Globalfoundries' CEO on why FD-SOI and why now

July 13, 2015 // By Peter Clarke
With its latest news Globalfoundries Inc. has not only confirmed itself as a supporter of the fully-depleted silicon-on-insulator (FD-SOI) approach to IC manufacturing but that it also thinks sufficiently highly of the technology that it wants it own exclusive processes to address a swathe of low power applications.

Globalfoundries has developed a 22nm FD-SOI platform of four processes based on a licensing deal it originally signed with STMicroelectronics back in 2012 (see Globalfoundries launches own FD-SOI processes). That was before Sanjay Jha arrived at the company to take over as CEO at the beginning of 2014. Jha had previously been CEO of Motorola Mobility Inc. – now part of Google – and COO at Qualcomm.

The original plan was for Globalfoundries to act as a licensed foundry supplier of a 28nm FD-SOI process developed by STMicroelectronics. Samsung has agreed to take on that role while Globalfoundries has been putting in its own engineering expertise to produce four process variants at a 22nm node that are tuned to applications behind the leading-edge catered to by 14nm FinFET processes.

Jha explained to eeNews Europe, why Globalfoundries is embracing FDSOI and why now.

"Beyond 28nm Moore's Law faced challenges and industry faced a choice; FinFET or FD-SOI. We have 14nm FinFET in our wafer fab in the United States. Through our acquisition of IBM Microelectronics we are going to have access to 7nm," Jha said. "FinFET is very good for high cost, high volume, high performance applications. But there are many applications in IoT and mobile which require much lower power consumption."

So why didn't Globalfoundries come earlier with a 28nm FD-SOI offering?

"The 22nm process overcomes some challenges at 28nm. The transistor is better and the 20 percent area scaling we get makes up for the cost of the substrate," Jha said. "That means we can offer better performance at the same cost as 28nm [alternatives to FD-SOI]," Jha added.

The higher cost of SOI wafer compared with a silicon wafer is one of the reasons often given as to why Intel and Taiwan Semiconductor Manufacturing Co. Ltd. (TSMC) rejected FD-SOI approach and single-minded pursued the FinFET.

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