New Microchip Breakthrough First Time in History

New Semiconductor Researchers from Georgia Tech in collaboration with Tianjin University in China have developed  a new semiconductor material. With this new technology we will be able to build computer chips that will run orders of magnitude faster than ever and this could really spark a new era  in electronics. According to Moore’s law the number of transistors in a chip doubles approximately every 2 years. This observation was first described by Gordon Moore in 1965. However later Moore himself predicted that this rate would eventually slow down and that’s unfortunately true it’s getting harder and even more expensive to fit more and more transistors into a single silicon. It seems like we are hitting some hard physical limits such as a size of a single atom still there are lots of efforts made by companies like TSMC, IBM, Imec and Intel to continue shrinking transistors even further and keep more slow going indefinitely.

Right now we in the ball park of about 200 million transistors per square millimeter and that’s an impressive number and according to this chart from i.e. the number of transistors per square millimeter has increased nearly 600,000  times over the last five decades. However further scaling the transistor technology down is a huge challenge so in order to move the needle forward we are starting to build in the third dimension start stacking transistors on top of each other in order to be a able to fit more of them in the same area imagine it like a big densely populated city starting to grow vertically but here again we see  a new problem emerging because vertically stacked devices suffer badly suffer from heat dissipation  problem. There is no heat dissipation path which leads to overheating. IBM is trying to address  this problem. For example last year here they’ve introduced vertical transistors and that’s a novel  architecture where the gate is placed vertically, however these devices are still in the research phase and meanwhile researchers are constantly looking for new and novel semiconductor materials  that can offer better spit and heat dissipation than silicon and potentially replace it.

Graphene

For a long time the researchers were investigating graphene as a possibility and Graphene is really  appealing due to its particular crystal structure and its exceptional ability to dissipate hit. In  fact it has much higher thermal conductivity than silicon and as you know heat is one of the major bottlenecks for many modern electronic devices. This is super important when chips are becoming smaller and smaller and more dens packed you don’t want your phone to overheat for example because overheating degrades the performance and also the lifespan of the device and can even cause a meltdown. So this new graphene based devices they’re much better at thermal management. 

Benefits of Graphene Based Devices

The good thing about graphene is not only can you make things smaller and faster and with  Pros and Cons less heat dissipation. You’re actually using proper properties of electrons that are not accessible in  Silicon however there is one fundamental problem with graphene. It’s actually not a semiconductor  it has zero band Gap zero electron volt band Gap. Let me explain why Band Gap in semiconductors is such a big deal? You know all the modern microchips like  CPUs GPUs they built of transistors which are in my humble opinion the most important invention  in the history of humanity and transistors are essentially tiny switches which can be turned on  and off and there state is basically controlled by the voltage applied to the control terminal. So the band Gap in transistors is fundamental because it determines a minimum energy required to make a transistor to switch between the states ideally. The researchers found a way to make a perfect semiconductor out of graphine. What they did? They grew graphene on top of a silicon carbite wafer and that’s pretty sick in the  Fab. They heated it up silicon carbide to very high temperatures over 1,000° C and then do it. Actually doing a semiconductor has nothing to do with banned or forbidden substances. It’s actually adding impurities into material to alter its electrical properties. Actually silicon  which is used in all the modern chips is also always doped. So it’s dope by altering the very properties of graphene they’ve managed to introduce a band Gap and they called this  new semiconductor semiconducting epigraphene or shortly SEG.

An epigraphene transistor I would  New Transistor Explained call it back to square one an old school planner transistor. All this semiconductor story started  with a planner transistor back in 1957, since then the transistors have evolved significantly. We went from a planner transistor to thin fat to gate all around and then to fat complimentar and then even to vertical transistors but with this new semiconductor we started all over again with planner transistor. The device is built on top of a silicon carbide substrate  and the semiconducting graphene is in the channel to put it simple when a gate to Source voltage is  bigger than a certain threshold. The transistor is turned on and the current is flowing through the channel. This is cool  that these new transistors can switch very quickly .They can support frequencies in the  range of terahertz and this is possible thanks to very high electron Mobility of graphene. Actually they were able to achieve 10 times higher electron Mobility with graphene than of what was till today possible with silicon chips and the mobility is defined by crystal structure the flatness and the  band structure of the graphene allows electron to move ballistically and in practice.

Manufacturing Process

This means  that an electron can move much faster through a semiconductor which promises much faster chips with less heat dissipation. What’s also promising about this work is that the manufacturing process.  They used is compatible with a conventional manufacturing process. So overall it seems like  an economically viable technology and what’s even more fascinating is that they’ve not just managed  to make a single graphene based chip in a lab but they’ve managed to fabricate it in large  quantity on large silicon carbide wafers defect free and this is a big deal because usually it’s a huge and time-consuming challenge to make a new semiconductor technology to be manufacturable at  scale.

Graphene Based Chips

If we can figure out the graphene based chips this will be huge but there are still  many technical challenges to overcome until we can bring it to mass production as always. The whole idea is not to integrate this new technology with traditional silicon technology as it often happens but rather to use it with silicon carbide technology which is already well-developed. Silicon carbide is replacing silicon in high voltage applications such as in Power Electronics, in electric cars for example it’s widely used in Tesla for power train and other applications and the reason is because of its amazing property is  to operate at higher temperatures to withstand higher resistance and higher electric fields.  Another Candidate, another Discovery. I believe from a year ago or so is Boron Arsenide another potential candidate  to replace good old silicon due to its amazing properties. It has improved charge Mobility over silicon and better heat conductivity 10 times higher thermal conductivity than silicon. This  has huge potential however researchers found it hard to fabricate born arsenide at high volume defect free. You know that silicon is fabricated quite cheaply in high quality and  the whole manufacturing process is very well established but maybe with enough efforts and also sufficient investment we can also develop Boron Arsenide but it will definitely take time as it took several decades for silicon.