First SOI wafers based on Smart Cut tech produced in China, target strong 200mm SOI demand in smart power, RF, automotive


Shanghai-based Simgui has produced the company’s first 200mm SOI wafers based on Soitec‘s Smart CutTM manufacturing technology (read the press release here). Samples will be going to customers in the coming weeks for qualification, with high-volume ramp planned for early 2016. Simgui will be selling the wafers directly to its own customers in China, and manufacturing on an OEM basis for Soitec customers worldwide. This includes manufacturing Soitec’s fabulously successful RFeSI90 substrates for LTE-A, 5G and Gigabit Wi-Fi in smartphones and other devices (read about those here), substantially increasing worldwide capacity to meet the recent rapid rise in demand.

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Simgui’s first 200mm SOI wafer manufactured using Soitec’s Smart Cut technology. (Courtesy: Simgui)

While overall worldwide 200mm wafer demand (including bulk and epi) has slipped a bit over the last year (they’re now accounting for a little over a quarter of all wafer sales), demand is increasing for certain types of 200mm SOI wafers. What’s driving it? RF and smart power (both of which are seeing big opps in automotive). SOI wafer leader Soitec, for example, is seeing an uptick of 20% in 200mm SOI wafers for smart power for automotive. RF is growing even faster.

The thick and thin of it

What’s different about these 200mm SOI wafers? It’s a question of layer thickness, quality and the manufacturing technology used to make them. Simgui and many others have been producing very “thick” 200mm SOI wafers for years. Traditionally in “thick” SOI (which has been used in things like power, aerospace, automotive, MEMS and sensors for decades), the top silicon might be up to anywhere from 2 µm to 300 µm thick, with an insulating box layer in the range of 3 µm (sometimes much more). But new apps in smart power and RF, for example, need a very high quality top silicon layer that might be as thin as 0.145µm for power*, or under 0.1µm for RF. The insulating layer also needs to be far thinner, and the bottom supporting layer also has to fulfill specific, advanced parameters.

(Bear in mind that these wafers for RF and smart power are still relatively thick compared to what you need for FD-SOI, for example, which is considered “ultra-thin”, and has ultra-uniform top silicon with a thickness in the range of 10-20 nm (0.01 – 0.02µm).)

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This graphic explains which SOI wafers are used for which applications, correlating top silicon and insulating buried oxide layer thicknesses.

There are several different manufacturing approaches to fabricating SOI wafers. To make the SOI wafers needed for new markets in smart power and RF, Simgui has opted to use Soitec’s Smart Cut technology (which is well-explained here). Smart Cut’s especially good for producing very high-quality wafers, with a thin and very uniform top layer of silicon and a thin layer of insulating buried oxide (BOx).

The new deal

Simgui is a high-tech company in Shanghai focused on supplying SOI wafers and providing foundry services for epi wafers. It was spun off from the Shanghai Institute of Microsystem and Information Technology (SIMIT) within the Chinese Academy of Sciences (CAS) and now is a joint venture with a group of investors from Silicon Valley. Both its SOI and epi businesses are growing dramatically.

With a surge in demand for leading-edge thick 200mm SOI wafers, Simgui partnered with Soitec, the industry’s SOI wafer leader, back in May 2014 (see that press release here).

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Simgui’s Fab-3 in Shanghai, where the company is manufacturing 200mm SOI wafers for power & RF using Soitec’s Smart Cut technology.

The May 2014 deal was a licensing and technology transfer agreement under which Simgui would manufacture Soitec’s 200-mm SOI wafers using Soitec’s proprietary Smart Cut™ technology. The news now is that it’s actually happened. Simgui has established a high-volume SOI manufacturing line to directly supply the Chinese market. In addition, Simgui will manufacture Soitec’s 200 mm SOI wafers for the global market outside China, expanding Soitec’s supply to customers worldwide in the growing RF and power markets. Beyond this initial cooperation, the two companies are expanding their collaborative efforts in the future to take advantage of their synergies.

China markets and beyond

Roughly a third of the fabs in China are 200mm (see SEMI’s map below). As recently noted by IC Insights, “Fabs running 200mm wafers will continue to be profitable for many more years and be used to fabricate numerous types of ICs, such as specialty memories, image sensors, display drivers, microcontrollers, analog products, and MEMS-based devices.”

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Current map of fabs by wafer diameter in China (as of April, 2015, Courtesy: SEMI)

The Soitec-Simgui partnership addresses two key areas: 1. China’s growing demand and 2. the need for an increase in worldwide production capacity for 200-mm SOI wafers used in fabricating semiconductors for RF and power applications. It’s also seen as a key element in establishing an SOI ecosystem in China.

Dr. Xi Wang, chairman of the board of directors of Simgui, notes that, “China is a hot spot for the IC industry today. The fast growth of China’s mobile devices demands a large number of SOI wafers. Through the collaboration with Soitec, Simgui has successfully demonstrated a strong technical ability and expanded capacity to meet our customers’ needs. In addition to the planned high-volume manufacturing of SOI wafers, we will continue to promote the SOI ecosystem in China and build a globally influential Chinese silicon industry.”

It’s also good news for Soitec’s 200mm SOI customers. “We are very pleased to have reached this major milestone with Simgui, which now has the capability to manufacture Soitec’s SOI products using our Smart Cut technology. This represents a key step in our commitment to increase capacity in response to the needs of our customers who serve the fast-growing RF and power markets, both in China and worldwide,” said Paul Boudre, CEO and chairman of the board of Soitec.

Which explains why the two companies see it as a win-win situation.

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