SOI wafers facilitate FinFET over oxide creation

July 09, 2012 // By Peter Clarke
Silicon wafer supplier MEMC Electronics Materials has announced the introduction of FOX-Si, a form of silicon-on-insulator (SOI) wafer designed to facilitate the creation of FinFETs with oxide dielectric isolation.

FinFETs, where transistors are contained in "fins" of silicon etched out of the wafer surface, have been introduced into commercial manufacturing by Intel Corp. at is 22-nm manufacturing node. Foundry chip makers had not been expected to introduce FinFETs until the 14-nm node. However, United Microelectronics Corp. (Hsinchu, Taiwan) has recently announced the licensing deal with IBM that includes FinFETs within a 20-nm process.

However, manufacturing conventional FinFETs on bulk silicon is difficult in high volume, particularly for system-on-chip devices, according to MEMC. Problems controlling fin dimensions can potentially compromise scalability.

The use of SOI for FinFET production has been proposed as the next step for Intel and foundries wishing to introduce FinFETs (see Intel FinFETs vary, may need SOI for shrink, says GSS).

An appropriate form of silicon-on-insulator (SOI) wafer, allows the production of controlled fin height and thereby deliver consistent channel width, the MEMC claimed.

MEMC said its FOX-Si wafers are priced "competitively" but did not disclose the price. MEMC allows customers to customize wafers and choose the depth of silicon above the oxide to "dial-in" in the fin height they want.

"Producing high-performance chips that don't require a lot of power continues to be the main challenge in creating multi-function mobile devices," said Gary Patton, vice president of semiconductor R&D at IBM, in a statement issued by MEMC. "Silicon-on-insulator substrates, such as those developed by MEMC, are fast becoming the preferred manufacturing solution for devices of the future as electronics makers seek out new types of custom silicon to meet the high requirements set by users to offer significant improvement in performance at low power."

"FinFETs built on MEMC FOX-Si wafers result in lower cost and better manufacturability, which will provide the industry with an important advantage," said Horacio Mendez, executive director of the SOI Industry Consortium, in the same statement.