TSMC seeing healthy yields on 7nm, Samsung delaying 7nm until EUV arrival

Here's a bit more process node technology news from the International Solid State Circuits Conference (ISSCC). EE Times was there and reports both Samsung and TSMC presented details about their future 7nm nodes.

Having lost most of Apple's business to TSMC, it seems Samsung is taking a step back for a while from the nanometermarketing game. One thing is for sure, there will be major differences between what both companies will call 7nm. TSMC presented a paper about a 7nm test chip it made that could pass for a commercial part, the company is currently making 16nm chips in volume for the iPhone 7 and needs to get its 7nm node ready for the iPhone 9 in 2018.

TSMC described its 7nm yields as healthy and said it made a 256Mbit SRAM test chip with a bit-cell area of 0.027mm², making it 0.34x smaller than its 16nm version. Jonathan Chang, director of TSMC’s memory group claims TSMC is "able to yield it right now, with a very, very healthy Vmin…that meets out design targets."

While the TSMC 7nm node seems to be pretty far along in the development process, what Samsung will name 7nm seems to be much more in research rather than development phase. EE Times notes Samsung will not rush to get a 7nm node in production, instead the company will aim to be the first to use, in some form, extreme ultraviolet lithography. As we've been saying for some time now, the naming of foundry processes is largely marketing so the key takeaway here is that while Samsung's 7nm node will arrive potentially a couple of years later later, it will be more advanced:

Samsung’s advance is more research and less development. The South Korean giant built an 8 Mbit test SRAM, really just a slice of a future commercial 7nm offering.

The chip was not built with EUV per se. Rather, Samsung developed a novel repair process which it tested on both existing and EUV steppers and--no surprise--found that EUV was much better. Generally, repair is not a production process, so the work says little about how Samsung is doing gearing up for EUV production at 7nm.

When EUV will be ready for mass production is still a big question mark. Experts believe it may be ready for production use on some critical layers around 2020.