First 7nm node test chips developed
IBM Research has successfully created the first 7nm node test chip with functioning transistors, a development that could lead to processors that boast four times the capacity of those on the market today.
Developed in conjunction with GlobalFoundries and Samsung, the new manufacturing technique has the potential to see a whopping 20 billion transistors packed into a chip the size of a fingernail.
In order to achieve this, the team used a number of non-conventional semiconductor manufacturing methods including the development of transistor channels made of silicon-germanium, or SiGe, rather than pure silicon. SiGe is better suited for smaller transistors because of the fact that it has higher electron mobility than pure silicon. Basically, when pure silicon is used, the gap between silicon nuclei gets so small that silicon atoms cannot carry enough current. When some germanium is added to the mix, electron mobility is increased.
These transistors are each only 7 nanometers wide – that's about 1/10,000th the width of a human hair and three times the width of a single strand of DNA. The smallest transistors in use on chips today are 14 nm wide, although 10 nm chips are in development by the likes of Intel and Samsung.
The team also used extreme ultraviolet lithography, or EUVL, for etching. Current chips are etched using an argon fluoride laser, which has a beam that is 193 nm wide. EUV beams are only 13.5 nm wide, however they are expensive and to date have been difficult to deploy on a commercial level.
We probably won’t see any 7 nm chips on the market for at least a few years because of how expensive they are to produce, but the breakthrough promises to help satisfy our appetite for more powerful, less energy-hungry devices in years to come, as well as help industry keep pace with Moore's Law as it continues the search for viable alternatives to silicon.