With the great news about FD-SOI foundry offerings from Samsung, ST and now GlobalFoundries, plus the IP availability, the wafer suppliers have chimed in to remind the ecosystem they’re ready to ramp (and have been for a number of years!). So the wafers are ready (and they truly are amazing), the processes ensuring high yield are in place, and high-volume capacity is ready to roll. Most recently in the wafer news, top-10 equipment supplier Screen Semi Solutions has joined the ecosystem (press release here) with wafer cleaning processes that ensure and maintain the requisite wafer uniformity in high-volume FD-SOI wafer production.
The industry-standard process for making all the different flavors of silicon-on-insulator (SOI) wafers (FD-SOI, RF-SOI, power, photonics, etc.) is Soitec’s Smart CutTM technology (you can learn about how it works here). Invented at Leti and industrialized by Soitec, Smart Cut made its world debut at Semicon West 20 years ago (!!) in 1995.
But for FD-SOI, the SOI wafers needed to meet new exigencies of extremely thin and uniform top silicon and an extremely thin insulating (aka Buried Oxide, or BOx) layer. Consider this: uniformity of the top silicon layer of Soitec FD-2D wafers (that’s the wafer product name) is guaranteed to within +/-5Å at all points on all wafers. This uniformity is equivalent to 5 mm over 3,000 km, which corresponds to approximately 0.2 inches over the distance between Chicago and San Francisco. Meeting this requirement is not new: Soitec announced they were ready for industrialization with this level of uniformity back in 2010.
As ST’s godfather of FD-SOI, Thomas Skotnicki, noted at Leti Days in Grenoble a few weeks, Soitec made even greater strides in the wafer requirements for the 14nm node. The FD-SOI offering just announced by GF is referred to as 22nm, but that really means a 14nm front-end with two double-patterning layers, and 28nm upper interconnect layers in the back-end.
Here’s what Paul Boudre, CEO of Soitec had to say about the GF announcement: “GlobalFoundries’ announcement is a key milestone for enabling the next generation of low-power electronics and we are very pleased to be GlobalFoundries’ strategic partner. Our ultra-thin SOI substrate is ready for high-volume manufacturing of 22FDX technology. With our two fabs and our worldwide licensing strategy, the market will enjoy all of the SOI wafers it needs for strong adoption. The markets we are addressing with this product will be key contributors to Soitec’s growth.”
For a number of years now, Shin‐Etsu Handotai (SEH), the world’s largest maker of silicon wafers, has been saying that they’re meeting the specs for FD-SOI wafers, too (read about that here), and can quickly expand capacity to meet rising demand. SEH is a $12.7 billion company supplying over 20% of the world’s bulk silicon wafers. They’ve been making SOI wafers since 1988, and in 1997 first introduced SOI wafers produced using Soitec’s Smart Cut technology. (And of course Soitec and SEH continue their long-standing collaboration – read about that here.)
So with the GF announcement, Nobuhiko Noto, general manager of SOI Division at SEH, said, “SEH welcomes this development, bringing FD-SOI products to the industry, and we look forward to the continuation of our work in extending the global supply chain for FD-SOI. We are very glad to be engaged in supporting the growth and development of the FD-SOI market, own FD-SOI wafer supply.”
So no worries about wafer supply. As Dr. Handel Jones, CEO of IBS notes, “Multi-source supply chain for substrates has been established, and wafer volumes can potentially be one million per year and more in the future. We are confident that Soitec and its licensing to supply the substrates required to allow FD-SOI wafer volumes to reach their potential.” (You can read Dr. Jones’ ASN posts here.)
Maximizing production yields with atomic-scale uniformity
At Semicon West, Soitec and Screen Semiconductor Solutions announced they have jointly developed a process to ensure atomic-scale uniformity of ±5 angstroms across the surface of all 300-mm FD-SOI wafers at the high-volumes the industry needs.
Maximizing FD-SOI production yields is of course critical to meeting worldwide market demand.
“Our strategic partnership with Screen enables us to produce ultra-thin FD-SOI substrates that meet chip makers’ challenging requirements of atomic level resolution in high volume manufacturing. Our FD-SOI wafers are already qualified by a number of foundries,” said Christophe Maleville, senior vice president of Soitec’s Digital Electronics Business Unit. “We are extremely pleased to see such high support from Screen on FD-SOI manufacturing and we are looking forward to finalize our on-going efforts on 14nm FD-SOI node.”
“Screen is proud to collaborate with Soitec on meeting this advanced technical challenge and enabling FD-SOI technology to reach high performance levels,” said Screen CTO Dr. Olivier Vatel.“Our high-productivity cleaning systems are available and ready for the FD-SOI ecosystem. As an industry leader, we will continue to deliver world-class products that contribute to our customers’ market success.”
Screen’s single-wafer cleaning equipment, the SU-3200, delivers the industry’s best productivity by using a perfect balance of high-speed cleaning capacity and highly stable processing. It has multiple process chambers, allowing each wafer to be treated individually with its own dedicated recipe based on incoming layer thicknesses, the desired surface condition to be achieved and a predictive etch model. Key advantages of the system include highly uniform chamber-to-chamber processing and cycle times for robust results, tight control of layer thicknesses, the elimination of defects and metal contamination and high productivity enabled by a versatile chemical-supply system.
So it’s all systems GO!