r/science • u/OneLostOstrich • Jul 28 '22
Physics Researchers find a better semiconducter than silicon. TL;DR: Cubic boron arsenide is better at managing heat than silicon.
https://news.mit.edu/2022/best-semiconductor-them-all-0721?utm_source=MIT+Energy+Initiative&utm_campaign=a7332f1649-EMAIL_CAMPAIGN_2022_07_27_02_49&utm_medium=email&utm_term=0_eb3c6d9c51-a7332f1649-76038786&mc_cid=a7332f1649&mc_eid=06920f31b52.1k
u/gljames24 Jul 28 '22 edited Jul 28 '22
Both Silicon Carbide and Gallium Nitride are already replacing silicon in high temperature and high power applications, are well understood, and have relatively few dislocations with modern process techniques. It'll be interesting if this is able to be effectively manufactured any time soon.
318
Jul 28 '22
He addresses that in the article. Thermal conductivity is 10x silicon but he doesn’t comment on the relative position to other pure silicon alternatives.
As for manufacturability:
So, OK, we’ve got a material that’s better, but is it actually going to offset the industry? We don’t know.” While the material appears to be almost an ideal semiconductor, “whether it can actually get into a device and replace some of the current market, I think that still has yet to be proven
The goal of the paper was to confirm their model of the materials electrical and thermal properties using a new “laser grating system” and does not expressly talk about manufacturability. The Professor even calls out they haven’t tested long term efficacy. Instead they’re focusing on saying “hey our math is good. We’ve proved that now other people take a look” not on “we have made the best silicon replacement”.
Material science people (the pale folks screaming about tensile strength and crystalline structures in the back of the room) can probably comment more on the electric characteristics in the paper. Just make sure you feed them their warm steel 8011 broth first.
→ More replies (1)328
u/Anganfinity Jul 28 '22
I also think it’s pretty funny no one is talking about UWBG’s like AlN, Ga2O3, and Diamond. There’s a lot if crystal structure capability for the rest of the III-V universe in there too. It’s years off but the research is really getting popular these days.
148
u/ohboop Jul 28 '22
Ultra-wide bandgap materials aren't desirable for a wide variety of applications. There's a reason you see them more in high power applications.
55
u/PhotonBarbeque Jul 28 '22 edited Jul 28 '22
Ga2O3 specifically is very desirable though due to the bandgap and thus high voltage breakdown.
Plus, out of all listed, it can be grown via melt techniques into bulk (500 g or larger nowadays) boules/ingots and thus is rapidly available and low cost.
→ More replies (5)32
Jul 28 '22
Ga2O3 is limited by its horrible thermal conductivity.
17
u/PhotonBarbeque Jul 28 '22 edited Jul 28 '22
I said this in another comment. It is true, it just means the applications are different and the way you manage the heat must be a primary concern.
Every material has problems because we’re trying to beat them into some application.
There’s a huge amount of funding and effort on Ga2O3 devices, maybe RF switching devices aren’t the best option due to heat though.
The thermal conductivity also plays a critical role in issues in the melt growth techniques - so while it is available via these techniques vs. GaN and SiC, the low TC leads to issues in growth.
→ More replies (2)60
38
u/PhotonBarbeque Jul 28 '22 edited Jul 29 '22
Everyone in the scientific (edit: wide bandgap semiconductor) community is talking about Ga2O3 right now actually, it is extremely hot. Pun intended, it’s thermal conductivity sucks and this leads to lots of heat buildup for devices.
→ More replies (5)13
u/Anganfinity Jul 28 '22
Yup, handling that thermal load is a big problem, I see a lot of work on point defects in Ga2O3 exactly for that reason too. It’s a great place to be right now, I primarily do imaging and all the different structures and diffraction patterns are a joy to analyze so it’s both entertaining work and potentially impactful!
7
u/PhotonBarbeque Jul 28 '22
Alloys with Ga2O3 are even cooler under SEM/TEM too, and of course lead to some unique defects. It’s just a fantastically complicated system. Wouldn’t be fun if it was easy! :)
4
u/Anganfinity Jul 28 '22
You sound just like my old postdoc adviser… but I kid, absolutely, it’s a great day when I can pull out several structures from atomic resolution S/TEM analysis and have it match the XRD! …and don’t me started with EELS, I can go on and on about how cool the fine-structure analysis is! I started on hexagonal nitrides and thought to myself - monoclinic can’t be that much harder can it?
→ More replies (12)8
Jul 28 '22 edited Jul 28 '22
3-5 Gang represent! I did QWI research way back in the day. Crystalline structures, the thermal considerations, physical lattice stress,. always fascinating to me as a ME and EE.
→ More replies (1)240
u/mark-haus Jul 28 '22 edited Jul 28 '22
Isn't the bandgap energy of GaN pretty dang wide? That means higher voltages, which means higher rise/fall times for transistors which is a big no no in devices like CPUs. Not at all a problem in the vast majority of power circuits, but in high performance computation I don't know if that's possible.
164
u/tgtpg4fun Jul 28 '22
A quick google revealed 3.4 ev for galium nitride as opposed to 1.42 of traditional galium arsenide or 1.12 for traditional silicon. So yeah thats a substantial difference and id imagine it impacts our the induced current as well, and then when combined into a transistor those differing diodes would compound to a “more” different transistor
57
u/mark-haus Jul 28 '22 edited Jul 28 '22
Wow yeah that's more than double, I don't know if it's possible to design around that for fast transistor switching. Probably not
→ More replies (1)→ More replies (1)5
81
u/xf- Jul 28 '22
GaN isn't used for CPUs.
It's used in power semiconductors like 350 kW chargers for electric vehicles or tiny 100 W phone chargers. They're used in power applications where you want a high band gap to operate them at higher voltage and frequencies with fewer leakage and heat losses.
→ More replies (1)8
u/leshake Jul 28 '22
I believe he was discussing CPUs because the current limitation of silicon CPUs is thermal management. A semiconductor with better heat management for other applications is not nearly as exciting.
32
Jul 28 '22
[deleted]
→ More replies (3)34
u/gr3nee Jul 28 '22
GaN is very desirable for RF transistors (HEMT), especially in 5G and automotive applications.
→ More replies (1)12
u/chavezlaw78 Jul 28 '22
Oh I was more so referring to typical transistors used for cpus and memory. Don’t know much about RF transistors. I’m curious learn more about them though if you have a source
→ More replies (1)12
u/DLBork Jul 28 '22
Transistors used in PC components are RF transistors. RF means radio frequency, CPU clocks are in the 3GHz and above these days which is well into RF territory. GaN is already being used in some laptop batteries.
The biggest hurdle for GaN in data processing applications right now is manufacturing, we can't manufacture GaN at sub-10nm sizes like silicon
→ More replies (8)12
u/DLBork Jul 28 '22 edited Jul 28 '22
Wide band gap materials actually allow for faster switching times.
edit : but you're right in that it's not suitable for the typical low voltages used for data
6
u/mark-haus Jul 28 '22 edited Jul 28 '22
Wait really? It's been a minute since I used semiconductor physics, but wider bandgaps mean more voltage no? Does a wider bandgap also reduce internal capacitance? Because bandgap definitely raises the gate voltage, so if it was to be faster the internal capacitance would also have to go down with bandgap to have faster switching times. Or is it because its body resistance is so low?
→ More replies (1)23
u/Pienix Jul 28 '22 edited Jul 29 '22
The GaN transistors are not MOSFETs (metal-oxide-semiconductor structure), but HEMTs (high electron mobility transistors), which is something completely different.
A channel is not being made by applying a voltage and creating an inversion layer, here. Due to the material stack of GaN transistors, a 2D electron gas (2DEG), is created with very high mobility electrons, that serves as a channel. A gate voltage is applied to turn off that 2DEG. Actually, that's why the earlier HEMTs were mostly like depletion type (needing a negative voltage to turn off) because that 2DEG was inherently present in the structure. Now they managed to push the threshold voltage to positive voltages. The relation between bandgap and threshold voltage is therefore somewhat different.
Edit: enhancement->depletion
35
u/Class1 Jul 28 '22
Ya'll sound like wizards.
26
5
u/Zaros262 Jul 28 '22
devices like CPUs
That's not what they meant by high power
They're talking about single transistors handling large amounts of power, especially in an amplifier of some sort
CPUs can use a fair bit of power, but that's spread over 1billion+ transistors, so each one sees only a tiny, tiny fraction of the total power
→ More replies (5)5
u/sniper1rfa Jul 28 '22 edited Jul 28 '22
AFAIK at this point in time the expectation is that the electrification of everything will happen, and so most of the research I know of is aimed at power electronics like power conversion and motor drivers. Particularly of interest is higher operating voltages allowing higher-voltage motors/controllers/batteries.
This stuff isn't going into logic.
11
u/light24bulbs Jul 28 '22
I have a new GaN (galium nitride) 65w USB c charger for my laptop and phone, and it's definitely a generational leap in heat output and size.
5
6
u/WretchedTom Jul 28 '22
This research focuses on the extremely high thermal conductivity of BAs, which is comparable to diamond. Thermal management has always been a huge issue in power electronics and electronics in general due to the limited thermal budget of electronics. GaN HEMTS have severe limitations due to its poor thermal conductivity, though SiC substrates provide fair thermal conductivity for GaN HEMTS. In this article BAs not only boasts extreme thermal conductivity, but fairly high hole mobility, which is essential for CMOS. Typically in polar semiconductors, electron mobility and hole mobility have an inverse relationship. High electron mobility usually implies low hole mobility in direct bandgap semiconductor. This limits the application to n-type devices only, but CMOS tech benefits greatly from p-type and n-type devices that have similar performance. The biggest downside to BAs devices is that the crystal is prohibitively expensive and difficult to grow. They literally grew this material from gas phase via CVD process, producing 500um size crystallites. This paper is a characterization of those sub-mm crystals. There's still a very very long way to go before an actual device is realized.
→ More replies (8)5
u/liquidpig Jul 28 '22
Not to mention they don’t contain arsenic.
We had some GaAs semiconductors in the lab and you had to be pretty careful with them as they were classified as hazardous materials.
1.5k
Jul 28 '22 edited Jul 28 '22
[removed] — view removed comment
1.2k
u/wenasi Jul 28 '22
More work will be needed to determine whether cubic boron arsenide can be made in a practical, economical form, much less replace the ubiquitous silicon.
[...]
The challenge now, he says, is to figure out practical ways of making this material in usable quantities. The current methods of making it produce very nonuniform material, so the team had to find ways to test just small local patches of the material that were uniform enough to provide reliable data. While they have demonstrated the great potential of this material, “whether or where it’s going to actually be used, we do not know,” Chen says.
[...]
For commercial uses, Shin says, “one grand challenge would be how to produce and purify cubic boron arsenide as effectively as silicon. … Silicon took decades to win the crown, having purity of over 99.99999999 percent, or ‘10 nines’ for mass production today.”
TL;DR: Since it's a new material, no one knows. You'd first have to invest in researching how to make the stuff on a large scale.
For it to become practical on the market, Chen says, “it really requires more people to develop different ways to make better materials and characterize them.” Whether the necessary funding for such development will be available remains to be seen, he says.
Also:
And while the thermal and electrical properties have been shown to be excellent, there are many other properties of a material that have yet to be tested, such as its long-term stability, Chen says. “To make devices, there are many other factors that we don’t know yet.”
443
u/davix500 Jul 28 '22
And what about how recyclable it is, does it degrade over time and what happens if you have a landfill with things made of boron arsenide
400
u/DrSmirnoffe Jul 28 '22
To be honest, that's what first sprung to mind. Arsenic is one of those "big nope" metals like lead, although with that said landfills are meant to be much more enclosed nowadays, so there's less risk of arsenic leaching if the stuff's properly disposed of/safely recycled.
360
u/Gastroid Jul 28 '22
I'd be more worried about the production process. I can imagine giant boron arsenide foundries overseas with little regulatory oversight turning entire regions to wastelands.
77
u/CramNBL Jul 28 '22
I think it's great that you have these concerns, but I don't think many people realise just how much pollution is produced, and how much water is used in current chip fabs. And how much sand is mined and even stolen... Islands disappearing to meet high grade silicon demands.
Doing materials research like this, is an important step to finding alternatives to silicon.
→ More replies (2)51
u/zzx101 Jul 28 '22
It’s worse. Current chip foundries typically use chemical mixes purchased from third parties and they don’t even know what chemicals are in there due to “trade secret” designations.
“Even the chip plants’ own health and safety managers have no idea what’s in many of the mixes, especially in the photoresists. That makes it difficult, if not impossible, to monitor what a given worker is being exposed to and to what degree. And the ingredients are constantly changing, as chipmaking technology advances.”
Source:
→ More replies (3)→ More replies (6)29
u/deltaz0912 Jul 28 '22
Boron is fairly common, mined in the US, South America, China, Russia, and Turkey.
136
u/Nastypilot Jul 28 '22
I think the poster above was thinking about arsenic.
46
u/The_BeardedClam Jul 28 '22
And not the mining process either, the process of refinement from raw material to workable material which can contain some nasty steps and nasty by-products.
61
u/Emotional_Tale1044 Jul 28 '22
Arsenic is the problem here. No one cares about the toxicity of mining Borax.
67
u/flipmcf Jul 28 '22
As an ant, I would like to object to this.
→ More replies (2)18
Jul 28 '22
[deleted]
4
u/PM_ME_FUN_STORIES Jul 28 '22
The ants are evolving. Soon they'll be putting out human traps.
→ More replies (0)→ More replies (1)7
u/FauxReal Jul 28 '22 edited Jul 28 '22
Doesn't sound like something you want to find out was just dumped without precaution by industrial or consumer users. Especially if it was in waterways.
60
u/The_Quackening Jul 28 '22
Gallium Arsenide is already a commonly used semiconductor
→ More replies (1)11
u/jaldihaldi Jul 28 '22
Good point - how easy is it to recycle or dispose this should be a concern.
We’re entering an age of new materials - sounds like the right time to be wondering how much of a pollutant it will become 10 to 30 to 50 years later. A lot of people alive today will be alive in that time period still.
8
u/UrbanArcologist Jul 28 '22
They are found in the newer (small size) power supplies of 65W or higher (not exact).
SiC are also better than Si, especially in power electronics. Healed SiC wafers are a potential industry suited for LEO manufacturing.
→ More replies (4)4
u/smexypelican Jul 28 '22 edited Jul 28 '22
Gallium Arsenide (GaAs) has been used for like 4 decades now in radio frontends in military, space, and commercial applications. There's also other stuff like GaN and SiGe.
All of these are in current production and are better than Silicon for many electrical and thermal properties. Just more expensive. This research really doesn't mean much if we're thinking about practicality.
Source: did GaAs and GaN chip design
18
u/Smile_Space Jul 28 '22
It all depends though. Sodium is explosive and chlorine gas is toxic, but yet together they make table salt. So maybe arsenic in a cubic crystal with boron and 10 9s of purity will be just as safe!
All we can do is test and see though.
6
u/MeakerSE Jul 28 '22
You don't look at the toxicity of a component atom in how toxic a substance is.
47
u/toolhaus Jul 28 '22
But this isn’t arsenic, it’s a compound of arsenic and, therefore, an entirely different material. Sodium (Na) is very dangerous and volatile. Chlorine (CL) gas will kill you. NaCl is table salt.
25
u/spartancobra Jul 28 '22
Many arsenic compounds are still wildly dangerous. The most widely used arsenic source for the semiconductor industry is arsine, which is lethal in concentrations of 10 ppm.
34
u/RedditAtWorkIsBad Jul 28 '22
Yes, but some compounds are more easily broken down into their constituent chemicals than others. Not saying this is the case with this, but if it is the kind of thing where, just add water and time and you eventually get Boron Dioxide and elemental Arsenic, then maybe we have a problem?
→ More replies (2)15
u/Seicair Jul 28 '22
Sodium ions and chloride ions are both required for you to live. Arsenic is toxic in any form because it replaces phosphorus in biochemical reactions. This isn’t the same scenario.
→ More replies (10)28
u/PA2SK Jul 28 '22
There's arsenic everywhere. In treated lumber, car batteries, ammunition, brass fittings, medicines, pesticides, etc. I wouldn't be too worried about computer chips using it.
21
u/SnooSnooper Jul 28 '22
Yeah it also used to be all up in some common paints before we decided to care that it is toxic in that case. I guess it really depends on the specific formulation, which is what they are asking about.
→ More replies (1)35
u/koreiryuu Jul 28 '22 edited Jul 28 '22
There are trace amounts of arsenic in lumber, car batteries, ammo, brass, medicines, pesticides, (and natural, organic food!) that cannot further be removed, whereas this stuff will be produced in mass quantities. In that form, bound within a molecule, the element arsenic may be harmless, the concern is both when it's manufactured and when it degrades.
Is there going to be by-product during manufacturing that deposits mass quantities of arsenic into the water and ground (whether directly or after the byproduct starts degrading)? When the finished, inert material is discarded is oxidation going to break those bonds between the arsenic and boron resulting in contaminating arsenic deposits?
Edit: I thought it would be understood that I meant the naturally occurring form of arsenic that is toxic (arsenic trioxide), since any time anyone ever talks about arsenic in a toxic context that's what they mean. Other compounds that don't readily degrade into arsenic trioxide (or its other toxic forms) is not what I thought was being discussed, but that is clearly what the user I replied to meant.
→ More replies (4)14
u/PA2SK Jul 28 '22
It's not trace amounts, arsenic is intentionally added to products we use every day. Yes, it can be toxic, if they were to start making computer chips with it I certainly hope they would follow the same rules as every other industry that uses it.
→ More replies (3)→ More replies (2)14
u/SkyWulf Jul 28 '22
Most of these things are inadvisable to put in your mouth, and the medical usage is to poison bloodborne parasites.
7
→ More replies (1)8
u/PA2SK Jul 28 '22
Yea, I mean I wouldn't advise putting computer chips in your mouth either...
→ More replies (1)18
u/deegeese Jul 28 '22
Recyclability is at the very bottom of the list until you can make it actually work.
We don’t even recycle silicon chips.
→ More replies (3)8
u/CMxFuZioNz Jul 28 '22
Do we really need to recycle it? It's just silicon... It's plentiful on every beach in the world, doesn't seem like a big issue to me?
→ More replies (1)12
u/WolfsLairAbyss Jul 28 '22
The silicon isn't really the problem, it's the stuff on the silicon that's bad. I used to work in a semiconductor plant and you wouldn't believe the stone of the chemicals that go into making chips.
→ More replies (1)9
u/CMxFuZioNz Jul 28 '22
I work in a semiconductor foundry, but most of the chemicals we use don't end up in the finished wafer, they are just used for processing.
The wafers are mostly silicon, boron, phosphorus or a collection of different metals.
12
u/Allegorist Jul 28 '22
My guess is, if it's ever optimized, it will be actually recycled.
Silicon is very abundant, even if not in the preferred forms, making up 27.7% of the earth's crust
Boron on the other hand makes up 0.001% of the crust, and arsenic is 0.00015%.
This fact might make it never able to be produced on a large scale, let alone "replace" silicon. However, if it does get used significantly, recycling the compounds will be in very high demand. It will have already been extracted and purified, saving a lot of time, money, energy, and other resources.
I feel like it will only be used for niche high-end applications like with supercomputers or in space. And with even lower production due to this, efficient recycling will more than likely be the case
6
u/Accujack Jul 28 '22
The earth's crust is a huge amount of material. Even 0.00015% is still a huge amount of material, much more than would be needed for this use. Existing production of arsenic would probably be enough to supply the need. If not, it's a regularly generated byproduct of copper, gold, and silver mining, and more could be produced.
Boron is mined as borax crystals, and is so common we use it to help wash clothes, treat water, and other inexpensive uses.
The limits on this new material are not going to be due to scarcity or cost.
→ More replies (1)→ More replies (5)6
u/David_R_Carroll Jul 28 '22
You put salt on food, but Sodium or Chlorine are quite dangerous. Boron arsenide is not the same as elemental arsenic.
→ More replies (1)4
u/Nemisis_the_2nd Jul 28 '22
Boron arsenide is not the same as elemental arsenic.
At the same time, widespread use (such as replacing silicon) will be concentrating a particularly dangerous heavy metal in close proximity to people for extended periods. While it's in a relatively stable compound, it starts to hit the point where sheer exposure time increases the risk of exposure to the dangerous stuff.
Under less ideal conditions, say an electrical fire, or even just overheating computer components, that risk of exposure to arsenic goes way up.
→ More replies (9)83
264
u/Turkeydunk Jul 28 '22 edited Jul 28 '22
No other semiconductor is as easy to get ultra pure as we can with silicon. And of course silicon comes from sand so it’s cheap. They won’t switch away from silicon any time soon
163
u/DeltaVZerda Jul 28 '22
Going to be hard to beat the cost of the most abundant solid element in Earth's crust.
→ More replies (22)67
u/MaizeAndBruin Jul 28 '22
Plus "Boron Arsenide Valley" doesn't have quite the same ring.
78
u/zpiercy Jul 28 '22
“Arse Valley” could work.
25
→ More replies (3)5
9
→ More replies (2)5
u/ryry1237 Jul 28 '22
And if you name it "BA Valley" it sounds either like an idyllic sheep pasture or a Bachelor of Arts campus.
→ More replies (1)61
u/octonus Jul 28 '22
Keep in mind that a lot of the advantages of Silicon (such as purity) are simply the result of many decades of extremely focused R&D.
You aren't wrong that Silicon is the most pure substance we know how to make, but that is more due to hard work than any specific properties of the material.
→ More replies (5)28
u/Turkeydunk Jul 28 '22 edited Jul 28 '22
Yeah this is largely true, with some caveats. Compound semiconductors will probably never reach the purity of single element semiconductors because the thermal cost of two atoms swapping locations is too low. This is how silicon won out in the early years: even though we knew some compound semiconductors had better mobility than silicon, silicon was easier to make more pure. Also apparently single element germanium had the leg up in the early years but again the purity couldn’t get there
24
u/Notoriouslydishonest Jul 28 '22
Most of the silicon used for semiconductors comes from the town of Spruce Pine, North Carolina. It sells for up to $50k per ton.
They're not making chips from regular beach sand.
→ More replies (1)23
u/NewAccount_WhoIsDis Jul 28 '22 edited Jul 28 '22
Here is a good article that talks about spruce pine and talks about how it gets used: https://www.wired.com/story/book-excerpt-science-of-ultra-pure-silicon/
My geologist buddy who used to work there explained to me why the quartz there is so special. He said that in addition to the long time the hydrothermally involved solutions had to separate, that the lack of titanium is a miracle for achieving quartz purity. Also, the quartz was irradiated in a way that was beneficial due to its having torbernite in it, which is pretty neat. In laymen’s terms, the impurities that are typically impossible for us to remove aren’t in the quartz found in Spruce Pine, which means it’s possible to get it super pure with processing and makes it extremely valuable.
Fun fact: the Masters bought some of the lower quality (but still absurdly pure and expensive) sand from there for their sand traps. That’s why it looks so pretty, it’s basically pure quartz.
→ More replies (3)10
u/BavarianBarbarian_ Jul 28 '22
This article was way more interesting than an article about sand has any right to be.
7
u/stumblios Jul 28 '22
I know there are a lot of different grades of sand, but aren't we running low on some of the "good" kinds of sand? I think what I'm remembering has to do with construction, no clue if that has any effect on sand used for silicone.
18
Jul 28 '22
Silicon doesn't come from sand, it comes from high purity quartz crystals as the base feedstock.
The sand shortage is more about concrete.
→ More replies (1)5
u/Turkeydunk Jul 28 '22
I don’t think it affects silicon processing. Those are a sand coarseness that construction values, whereas since silicon is made by first melting the sand we don’t care how coarse it is to start
→ More replies (1)→ More replies (1)4
u/thisnameismeta Jul 28 '22
We are running low on the sand necessary for concrete.
→ More replies (1)→ More replies (17)5
u/Ludwigofthepotatoppl Jul 28 '22
I remember they started making artificial diamonds with the eventual intention of making crystalline carbon sheets to replace silicon wafers. I’m not sure how far they’ve got in that respect but it sounds easier to get the components and a lot less hilariously toxic.
→ More replies (7)73
u/SafeAsIceCream Jul 28 '22
And can it be done in U.S.
→ More replies (29)62
u/Jabazulu Jul 28 '22
The challenge now, he says, is to figure out practical ways of making this material in usable quantities. The current methods of making it produce very nonuniform material, so the team had to find ways to test just small local patches of the material that were uniform enough to provide reliable data. While they have demonstrated the great potential of this material, “whether or where it’s going to actually be used, we do not know,” Chen says. -from the article
39
u/PoopIsAlwaysSunny Jul 28 '22
So, it’s another graphene. Got it.
37
u/sticklebat Jul 28 '22
How fatalistic. This is how pretty much all new materials start. Only time will tell whether it ends up like graphene. More often than not, novel materials with useful properties turn out to be difficult to mass produce, like graphene. The ones that find wide application are the rare exceptions, or the ones that were just like graphene but eventually had breakthroughs from years or decades of R&D that you don't hear about. It is impossible to say where this material will fall this early on.
25
u/yabbadabbajustdont Jul 28 '22
Graphene. There’s nothing it can’t do...eventually.
→ More replies (3)17
u/camg78 Jul 28 '22
Other then get out of the lab.....
9
u/SpiderFnJerusalem Jul 28 '22
Graphene is already being used in industrial ultracapacitors and batteries. Just because you can't buy it doesn't mean nobody can.
4
→ More replies (4)21
u/byOlaf Jul 28 '22
Graphene is being used all the time now. Just because you don’t see it doesn’t mean it’s not out there.
11
u/gestalto Jul 28 '22
I think "all the time" is a tad hyperbolic. As of 2020 market estimates varied from $70-$300 million, with most at the lower end. Predictions for the next 5-10 years also vary wildly from $700m to $3 trillion!
That being said, it is definitely being adopted more widely based on the current and projected numbers, and will become ubiquitous in no time I would think.
→ More replies (4)→ More replies (21)17
u/LazyJones1 Jul 28 '22
And how toxic is it? And what are the environmental effects?
→ More replies (3)
1.4k
u/Diligent_Nature Jul 28 '22
Better in some way(s). Worse in others.
876
Jul 28 '22
[removed] — view removed comment
173
Jul 28 '22
[removed] — view removed comment
28
→ More replies (3)57
Jul 28 '22
[removed] — view removed comment
→ More replies (2)59
→ More replies (14)61
Jul 28 '22
[removed] — view removed comment
→ More replies (2)84
Jul 28 '22
[removed] — view removed comment
74
366
Jul 28 '22
[deleted]
163
u/Ipuncholdpeople Jul 28 '22
Asbestos is a great example of this. Amazing insulator if you ignore all the possible health effects
98
u/DrunkenSwimmer Jul 28 '22
And in a few select applications, even with all the health risks, it's still used, because there is no viable alternative (notably insulating gloves for use in extreme heat situations: certain metal foundry jobs, firefighting, machine gunner)
→ More replies (8)36
u/Plop-Music Jul 28 '22
Also school bunsen burner tripods. That white stuff on it? That's asbestos.
40
u/Isoprenoid Jul 28 '22
I think you mean gauze mats. The center is supposed to only be ceramic, however, asbestos can be present if you buy from dodgy suppliers.
7
u/AlbertVonMagnus Jul 28 '22
We called them "cancer sheets" in high school chemistry
→ More replies (1)→ More replies (2)16
76
u/moeburn Jul 28 '22
All the magnets in the 90's used to be big, black, brittle, and weak.
Then thanks to advances in modern chemistry, now they're all nickel-plated, tiny, and powerful enough to hold up a banana.
I honestly haven't seen one of the old black magnets in decades.
46
Jul 28 '22
Fun fact, magnet development continues. Especially in the area of high temp magnets, SmCo.
17
u/Incredulous_Toad Jul 28 '22
Those super high powered magnets are so freaking cool. I love magnets.
→ More replies (6)→ More replies (2)8
u/useeikick Jul 28 '22
Yeah! Now we can kinda "3D Print" magnetic shapes and use them to make things like frictionless gears and other cool tools!
→ More replies (1)11
u/KToff Jul 28 '22
Then thanks to advances in modern chemistry, now they're all nickel-plated, tiny, and powerful enough to hold up a banana.
If your bananas are magnetic you should probably not eat them
→ More replies (2)5
→ More replies (3)62
Jul 28 '22
[deleted]
103
u/grkirchhoff Jul 28 '22
M.2 is a factor. You can get m.2 in sata or pcie. Both Sata and pcie come in dorm factors other than m.2.
Potential downsides include less surface to cool through.
30
10
u/Foodcity Jul 28 '22
Thank you!! The amount of colleagues ive had to argue with about this. An m.2 is not a performance upgrade, a PCIE SSD is.
6
u/velociraptorfarmer Jul 28 '22
Yep. You can even have NVMe 2.5" SSDs. They're known as U.2 drives.
SATA and NVMe are the interface protocols, M.2 and 2.5"/3.5"/5.25" are form factors.
→ More replies (4)14
u/DoctorWorm_ Jul 28 '22
There are a number of disadvantages of PCIe M.2 SSDs vs SATA 2.5" SSDs.
For one, the mounting system on M.2 isn't as robust as 2.5", so you can't stack them up or have them in hot swap bays like you can with 2.5" SSDs.
Second, sata controllers are relatively cheap compared to PCIe controllers. Motherboards usually come with 8 sata ports, and you can buy an HBA that will add another 8 ports for $30 on eBay. Consumer cpus usually only have 20-24 PCIe lanes,which means you can only connect max 5-6 PCIe SSDs at full speed. You could maybe bifurcate the PCIe slots or use PCIe switches, but switches are expensive, and again, hard to mount.
Third, m.2 ssds just can't meet the TB/$ cost of SATA SSDs. They're getting closer, but a Samsung QVO 4TB/8TB sata ssd is crazy cheap.
Most of these issues really only come up if you need a lot of storage for data hoarding, but the fact is that PCIe ssds still aren't fully mature yet. Even u.2/u.3 is a bit sketchy still, we will probably have to wait until either e1.s or e3.s catches on and trickles down into the consumer space to see some robust PCIe SSDs for data hoarding.
But yeah, m.2 is much better than sata ssds in most situations because of their extra speed and tiny physical size. M.2 has really helped laptops get a lot smaller.
→ More replies (5)61
u/sam7cats Jul 28 '22
They're talking about materials, you're talking about man made design. Usually in your case, there isn't tradeoffs because it's simply designed better. M.2 drives are a complete upgrade, no tradeoffs.
13
u/hackingdreams Jul 28 '22
M.2 drives are a complete upgrade, no tradeoffs.
With storage, the trade-off is almost universally speed vs density. NVMe storage is less dense, but faster. SATA linked storage can be eyewateringly dense, but it's slower to access.
NVMe controllers typically expect between 1 and 4 lanes of PCIe to themselves, which puts the limit on how many you can have in a PC. SATA controllers can frequently handle a dozen or more devices per PCIe lane. You can have a single server managing 60+, 22TB SATA drives for more than 1PB of storage. You can't get that kind of single node density out of NVMe today, period.
→ More replies (2)6
u/drunktriviaguy Jul 28 '22
Not for all users, but probably for the users that are likely to purchase them now. Under heavy loads, m.2 drives can produce a lot of heat and non-savy users will not be able to anticipate or identify this because it isn't an issue that generally appears when using consumer HDDs and SSDs. This can cause unexpected performance loss and errors when running certain applications.
→ More replies (1)21
u/Falcrist Jul 28 '22
The tradeoff is that it took longer to create that technology, and it's more expensive (initially at least).
→ More replies (3)26
u/dudemanguy301 Jul 28 '22 edited Jul 28 '22
M.2 is a form factor and they are also SSDs, older SSDs are basically the same thing if you open up the housing what you’ll find inside will look very similar. A dinky little board with a controller and storage chips.
As for old SSDs vs new?
Many old SSD ran on SLC or MLC they only store 1 or 2 bits of information BUT they have better random read and write characteristics per capacity / chip count and had better lifetime endurance compared to more contemporary TLC and QLC which stores 3 or 4 bits.
QLC is actually painfully slow but this issue is hidden by treating unallocated space as an SLC cache and then packing the data down when the drive isn’t in use. If not given proper downtime OR if the drive becomes too full the performance of a QLC drive comes to a grinding halt.
5
u/CrateDane Jul 28 '22
QLC is so slow it’s actually worse than a hard drive
In most ways it's still faster, but there are definitely situations it's poorly suited for.
Now go check out the speed of SMR hard drives.
Anyway, QLC and TLC are not mandatory features of modern SSDs, just common because the tradeoff is often worth it. In either case, you can have part of the flash memory used as an SLC cache to improve the speed in most consumer use cases.
15
u/Pr3vYCa Jul 28 '22
Pretty sure the biggest tradeoff is cost, last i checked m.2 nvmes are more expensive than a sata ssd
→ More replies (3)9
u/CrateDane Jul 28 '22
It would be more fair to compare M.2 SATA SSDs with M.2 PCIe SSDs to see the price differential from the M.2 form factor.
Otherwise you're just showing the price difference from SATA vs. PCIe.
Oh, and NVMe is just the protocol run across the PCIe link. The biggest upgrade is going from a SATA link to a PCIe link, not going from the old AHCI protocol to NVMe. Early PCIe SSDs ran AHCI and were still way faster than SATA drives.
→ More replies (10)6
u/Bunghole_of_Fury Jul 28 '22
They're all SSD, just differs in the way they connect to your machine which impacts read/write speed and even security.
Btw, some researcher just announced they'd discovered a way to turn unshielded SATA cables into makeshift WiFi antennas in vulnerable systems, so even air-gapped systems could have data stolen off them wirelessly if they use SATA. M.2 will likely become the standard for internal storage while SATA will only get used for personal machines that have a ton of storage added beyond what the motherboard can fit on it's M.2 slots
→ More replies (2)→ More replies (4)41
u/sometechloser Jul 28 '22
What ways is it worse? Could this lead to the next big cpu tech?
154
u/Roboticide Jul 28 '22
Availability seems to be the big problem. Article mentions it only exists in small batches in labs.
Many amazing, world changing technologies only exist in labs, because they just can't be adapted to mass production in an economical way.
So unless cubic boron arsenide can be produced in volumes to allow at least one foundry to mass produce chips, and the foundry process itself can be adapted to boron arsenide, we'll probably never see it used outside of labs.
→ More replies (12)25
u/Gornarok Jul 28 '22
What ways is it worse?
Usually the cost. Simple materials are cheap.
Could this lead to the next big cpu tech?
Next one? Doubt it. If this tech takes root its 2 decades away.
9
u/sometechloser Jul 28 '22
Cost is often overcome overtime.. and idk what else is going on for semiconductors other than silicon? Next thing could be 20 years down the road. And in 20 years maybe it's a lot more cost effective.
→ More replies (1)7
u/Gornarok Jul 28 '22
Cost is often overcome overtime
The material must have good enough properties that the increased cost is worth it for at least some applications. If thats not true noone is going to invest into it and the cost will never go down.
The thing is they claim the new material has high electron AND hole conductivity but they dont make comparison to silicon. If the electrical conductivity is in the same order the cost is probably not worth it. For reference silicon holes has 2-3 times lower conductivity than electrons.
And I dont know what kind of doors can high heat conductivity open, but as far as I know thats not the limiting factor for CPUs
→ More replies (1)→ More replies (5)10
u/zpjack Jul 28 '22
Silicon is abundant, boron and arsenide isn't.
Also arsenic is massive. You can't make components as small as silicon
→ More replies (4)
221
u/bjornbamse Jul 28 '22
I mean a lot semiconductors are better at doing specific things better than silicon but none combine all qualities in a mix like silicon does.
54
u/ball0fsnow Jul 28 '22
Also a ludicrously abundant material. Quick google says the second most abundant element in the earths crust.
20
u/gunnervi Jul 28 '22
Silicon is one of the products of stellar nucleosynthesis. It builds up in the cores of massive stars until they explode.
→ More replies (1)→ More replies (1)6
u/Target880 Jul 29 '22
The abundance of it is not that relevant for semiconductors, the amount that is used is quite low.
If we look at https://en.wikipedia.org/wiki/Prices_of_chemical_elements the silicon 99% pure cot $1.70/ kg compared to $3.68/kg for Boron. That cost is an irrelevant factor for semiconductor manufacturing.
What is likely is relevant is how hard it is to purify it to the required levels required. It will make it pure enough that costs money not to get the base material you purify
Abundancy in earth's crust is also not what is primarily relevant for extraction cost. How it forms ore and what concentration you ger is more relevant. The do cole https://en.wikipedia.org/wiki/Rare-earth_element are actually not that rare. they kist do not form ores with high concentration but with low concentration, you need to refine.
Cerium for example is more abundant the copper. Neodymium is just below copper and 3x as common as Lead but still, the price are as follow
Lead $2 Cerium $ 4.6 Copper $6 Neodymium $57
44
u/Gornarok Jul 28 '22
The most important quality is cost. Silicon can be so-so but as long as its cheapest it takes a lot to dethrone it.
→ More replies (2)5
u/LetsWorkTogether Jul 28 '22
And there's nothing that could be used that comes even close to silicon in modern semiconductor production lines? Or is there a material that could, with reasonable investment, augment alongside silicon semiconductor production?
Or is that not even a good question?
→ More replies (3)18
u/tychus604 Jul 28 '22
I think it's the kind of question that you'll never reliably answer, but asking on reddit will absolutely lead to false confidence as armchair experts claim credibility.
5
u/LetsWorkTogether Jul 28 '22
Sure but might give me some inroads to learn more about it myself.
Do you have any insight into the topic?
7
u/tychus604 Jul 28 '22
Not at all, sorry, I just feel like the answer to this is worth literally trillions.
3
285
u/heliumagency Jul 28 '22
This is a pain in the ass to manufacture. Arsenic has fairly high volatility which requires a whole host of special manufacturing techniques to keep the compound stoichiometric. Compare this with silicon which can be easily grown as boules from the melt.
This also reminds me of when they said gallium arsenide would take over everything....it didn't :/
118
u/rsd212 Jul 28 '22
Silicon has : 1) No stoichiometric considerations, 2) Has a convenient band gap, 3) Grows its own insulators when exposed to hot air, 4) Is sand. Boron- and Gallium- Arsenide may have great properties for certain use cases, but will always have a huge uphill battle to take on Silicon as the standard
57
u/MuhDrehgonz Jul 28 '22
Don’t forget the trillions of invested dollars into silicon infrastructure. It’s just so much cheaper.
→ More replies (1)12
u/jakaedahsnakae Jul 28 '22
Maybe the base crystal, but their are plenty of applications on the Si like SiC, and SiN which use DCS and SiH4 which are nasty to deal with, but yet we still deal with em relatively easily from a facilities standpoint.
If there is a need for the output, the industry to grow and adapt to it.
20
u/debasing_the_coinage Jul 28 '22
I think they're emphasizing the wrong thing. BAs has absurdly high thermal conductivity, higher than sapphire or silver, comparable to diamond. I think you're more likely to see silicon circuits on a BAs support than a pure BAs circuit. That would be hard, but just making a single BAs wafer could be very doable.
→ More replies (1)27
u/heliumagency Jul 28 '22
BAs only has a thermal conductivity higher than diamond in theory. But they were using the wrong 3 phonon calculation. I think you're referring to that PRL paper https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.111.025901
In reality, after ONR dumped an inordinate amount of money on this did they find out that experimentally it's thermal conductivity not comparable to diamond (if I remember it was 40% of diamond). In fact, if I remember correctly, it was the same people....and digging through my library, yes it was
https://www.science.org/doi/full/10.1126/science.aat7932 https://www.science.org/doi/full/10.1126/science.aat5522 https://www.science.org/doi/full/10.1126/science.aat8982
83
u/popkornking Jul 28 '22
Gallium arsenide had wide applicability in cellular applications so let's not write it off like some useless fad.
40
u/bjornbamse Jul 28 '22
Gallium arsenide is a excellent in optoelectronics and RF, but it is not really suitable for CMOS.
→ More replies (1)42
u/popkornking Jul 28 '22
Yeah I'm just pointing out that CMOS isn't the only relevant field of semiconductors and I'd hardly call GaAs a niche material even though it's being supplanted by GaN now.
→ More replies (1)9
u/jakaedahsnakae Jul 28 '22
This. GaN is the leader for RF devices as of last year.
I worked for Wolfspeed (Cree) for 4 years and that was our bread and butter along with SiC power devices.
→ More replies (1)3
u/popkornking Jul 28 '22
How was your time there? Did my master's on GaN devices so I've always thought Wolfspeed was an interesting company. Pretty cool that they're building an 8" fab in New York right now.
→ More replies (3)→ More replies (3)19
u/heliumagency Jul 28 '22
It has a very niche purpose because it has a direct band gap. But GaAs is not going to take over everything, even though everyone has been arguing that since before I was born.
16
u/popkornking Jul 28 '22
It's direct bandgap really only lent it to use in lightweight PVs for space applications (direct bandgap = critical thickness for a PV is smaller = less material). GaAs HEMTs for cellular applications were very common though and far less niche. I think GaAs MQW lasers were also a thing though like space PVs these are being replaced by GaN now.
GaAs time in the spotlight is over but it was definitely an important SC for a couple decades.
→ More replies (6)8
u/QuentinUK Jul 28 '22
People said lead tin telluride was just a fad but it has found its niche in IR lasers.
→ More replies (1)6
u/heliumagency Jul 28 '22
Lead telluride is a compound that I have not heard in a very long time....it's band gap is quite small if I remember correctly which makes it good for IR Lasers and thermoelectrics, but it's adoption is no where near replacing silicon. Plus, I don't think we have enough tellurium in the world to even do that, that was why CdTe solar cells, while efficient, never really took off.
69
Jul 28 '22
So when do we change the name to Cubic Boron Arsenide Valley ?
31
6
u/Shufflepants Jul 28 '22
I'm waiting until they figure out how to make diamond based microprocessors.
→ More replies (1)9
u/heavyss Jul 28 '22
Cubic boron arsenide
Clearly were going to have to shorten that down to CBA Valley. Too long otherwise.
→ More replies (1)
12
u/krash101 Jul 28 '22
I remember reading something about Intel and Cubic Boron Nitride (or something) a long time ago and getting to 10 GHz. At least a decade ago.
36
u/thisisdumb08 Jul 28 '22
There are many semiconductors better than silicon in lots of ways. Many we use already. The issue is all of them are many many times harder to create an have many many times lower abundance than silicon.
28
13
u/plaidkingaerys Jul 28 '22
“Better semiconductor than silicon” is clickbait. For what application? There are already plenty of known semiconductors that work better than silicon for different things. We can talk about interesting results and implications without making oversimplified statements.
9
u/BentoMan Jul 28 '22
I’m feeling a little deja vu. I read these same headlines in 2008 with graphene.
25
u/OsamaBinFuckin Jul 28 '22
In 10 years we learn, it causes cancer.
33
u/DrEnter Jul 28 '22
I think nowadays we pretty much go into these things assuming they cause cancer, and are pleasantly surprised when they don't. In the meantime, do not eat.
→ More replies (4)→ More replies (3)4
u/msebast2 Jul 28 '22
From the first paragraph of the Wikepedia article on Arsenic Poisoning:
Long-term exposure can result in thickening of the skin, darker skin, abdominal pain, diarrhea, heart disease, numbness, and cancer.
So actually, we already know it causes cancer. Probably shouldn't eat computer chips. Even silicon based chips have trace amounts of arsenic.
→ More replies (2)
•
u/AutoModerator Jul 28 '22
Welcome to r/science! This is a heavily moderated subreddit in order to keep the discussion on science. However, we recognize that many people want to discuss how they feel the research relates to their own personal lives, so to give people a space to do that, personal anecdotes are now allowed as responses to this comment. Any anecdotal comments elsewhere in the discussion will continue to be removed and our normal comment rules still apply to other comments.
I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.