News Article
Imec’s SiGe pFETs show superior characteristics for CMOS
The implant-free quantum-well (IF-QW) devices with a buried SiGe channel have good electrostatic gate control and a low variability of key electrical parameters, significantly improving device performance.
Imec has successfully fabricated IF-QW pFETs with an embedded SiGe source/drain.
These devices show an excellent short channel control and are claimed to have a record logic performance. A benchmark against various competing technologies showed competitive results. Finally, the device performance was also demonstrated at low operating voltages. These results prove that this device architecture is a viable option for the 16nm technology node and beyond.
Next-generation multimedia applications will require ICs that are at the same time very powerful and low power. One attractive option is to use high-mobility channels, for example using SiGe with a high germanium content. However, further scaling of the gate length will require a better electrostatic gate control, and a low variability of the key electrical parameters. Imec and its partners have recently shown that the IF-QW concept with a buried SiGe channel meets these requirements while significantly improving the device performance.
Imec is also announcing the development of 2nd generation of SiGe45% IF-QW pFETs, processed on standard 300mm STI wafers. Compared to earlier IF-QW devices, the raised SiGe and silicon substrate are recessed and replaced with a thick SiGe25% epi-layer to form the source/drain electrodes. Imec has also developed process modules that minimise local variations and maximise the device performance.
This has resulted in an excellent short channel control, with a drain induced barrier lowering of ~110mV/V at 35nm-LG and a record 1mA/µm-Ion at -1V. For lower operating voltages, an increased performance was demonstrated. The devices were benchmarked at various operating voltages against state-of-the-art technologies such as SOI nFETs or SiGe-FET, showing at least equivalent results. These results show that SiGe IF-QW devices with embedded source drain form a promising architecture for integration on bulk Si, from the 16nm node onwards.
These results were obtained in cooperation with imec’s key partners in its core CMOS programs Globalfoundries, Intel, Micron, Panasonic, Samsung, TSMC, Elpida, Hynix, Fujitsu and Sony.
Imec will show these results at SEMICON WEST, at booth #1724, South Hall, Moscone Centre, San Francisco, US through 12-14 July 2011.
