I've been following this topic for quite some time. Probably because I always wanted to be an EE/HPC engineer, but never was. When you listen to what guys from IBM, Intel, Applied Materials etc. have to say, then it seems that 5nm will probably be the last silicon based process. III-V (Boron, Nitrogen group) type of materials will then be next, with most likely candidate being GaAs (Gallium arsenide) which is already being used in niche productions.
What is more interesting than semiconductor base used is lithography process. Deep UV (immersion, using refraction of medium such as water) lithography currently used is showing its limits for ever smaller features. So, they came up with Extreme UV lithography which uses mirrors to project features onto surface, because at that short wavelength everything is opaque. Applied materials has a machine with EUVL apparently (there is one on their site and a nice video with description) as well as ASML (their machine reportedly costs $88 million).
There is a probability that with new semiconductor base (group III-V) there will be a reset back to 22nm or similar and a race down to bottom once again. We'll see.
GaN, SiC and Diamond are also very good candidate materials.
Also don't forget multi-patterning, which is what has allowed us to get to 14nm in the first place. I reckon Intel will ditch their immersion lithography which they love so dearly and move on to other techniques, which is when I will actually get excited about these techniques. X-Ray Lithography is also being investigated and seems to hold some promise.
The crazy thing about all these advancements is that no one knows what the future will hold, and right now we are essentially living under a renaissance era, witnessing the death of Silicon. I just hope the stuff I'm working on succeeds so I can make that cash money.
Intel already said they are moving to EUV from immersion lithography multi patterning, but tech isn't ready for them in another year or two. X-ray lithography has been used in the past, if I'm not mistaken. I didn't know there is an interest to bring it back. I know there is some research in Electron beam lithography, but jitter and slowness of it is a major hurdle.
What are you working on - graphene? In any case, very very interesting times ahead. Projections are that 2020 will see the last of the cycles (5nm) for Silicon. And that's only a few years away!
You don't know if Intel's tech is ready. It's classified for the machine manufacturers to disclose if Intel's their customer. I tried really hard to ask this Intel guy at IEDM what they're using for 10nm research and he wouldn't say anything.
E-beam lithography has been the work horse for research in fabrication for decades now. You can't get better resolution than E-beam lithography. The wavelength of an electron at 5kV acceleration is something like 0.017 nm. There are some crazy people who are trying to make E-beam systems for production processes (multiple beams, etc.), but I don't think E-beam will ever see use outside of research.
It might be due to my limited scope of knowledge, but how would one scale E-beam to a production capacity anyways?
Thanks for the link. I'll have to cross-read it with a lot of info though since it's 'a bit' over my head. I'm already lost at 1D and how it relates to, well, anything. I still can't warp my head around 1D geometry.
Hah, I've heard that! It's a really interesting field that blends physics, maths, chemistry, electronic and electrical engineering, computer science and other fields. Really amazing even to the outsiders like me, and it's not too hard to follow.
One of the cooler research topics going on now is the use of block copolymers for even more precise lithography, at the nano-scale. Really interesting stuff!
What is more interesting than semiconductor base used is lithography process. Deep UV (immersion, using refraction of medium such as water) lithography currently used is showing its limits for ever smaller features. So, they came up with Extreme UV lithography which uses mirrors to project features onto surface, because at that short wavelength everything is opaque. Applied materials has a machine with EUVL apparently (there is one on their site and a nice video with description) as well as ASML (their machine reportedly costs $88 million).
There is a probability that with new semiconductor base (group III-V) there will be a reset back to 22nm or similar and a race down to bottom once again. We'll see.