Shifting CMOS loyalties affect embedded

While it may be difficult to assess the impact of Crolles2's demise on the Grenoble cluster and and the alliance's own founders, the link between CMOS technology and advanced embedded applications is inextricable.

Lacking the R&D capital and resources to pursue their own process advances, Crolles2's partners launched programs that provided pilot process steps and the basic building blocks of CMOS technology. Those developments trickled down to benefit many of the Minalogic embedded development cluster's smaller, highly innovative companies.

One example was the 2005 development by Crolles2 partners NXP (then Philips) and Freescale Semiconductor of an ultra-dense SRAM cell in a 45-nm low-cost, low-power CMOS process. The six-transistor SRAM bit cell has application in embedded systems, such as battery-powered devices, mobile phones and MP3 players.

Recent research advances at Crolles2 have underscored ST's leadership in CMOS image sensor technology, including such breakthroughs as ST's innovative process for 1.75-µm pixel image sensors, yielding improvements in such key parameters as light conversion gain, saturation voltage, sensitivity, dark current and noise. The copper-based ST process, introduced at the International Electron Devices Meeting IEDM a year ago, targeted mobile phone applications at low light levels.

A joint project of France's atomic energy commission and ST that benefited ST's research partner was the fabrication of a CMOS image sensor with 3-µm pixel pitch built with amorphous silicon. Experimental results demonstrated an unparalleled enhancement in amorphous silicon reliability under high levels of illumination, achieved by material, process and pixel design improvements.