Date:12th July 2011
Implant-free quantum-well SiGe pFETs for
low power and high performance semiconductor devices
Imec has announced that it has successfully fabricated
implant-free quantum-well (IF-QW) pFETs with an embedded
silicon-germanium (SiGe) source/drain offering excellent
short channel control, record logic performance to address
the market demand of high performance but low power semicondcutor
ICs. Imec claims it has benchmarked this tech against various
competing technologies to find competitive results. These
devices were also demonstrated at low operating voltage.
Imec finds this device architecture is a viable option for
the 16nm technology node and beyond.
SiGe (silicon-germanium) based semiconductor devices with
a high Ge content offer high mobility. IF-QW concept with
a buried SiGe channel meets the performance requirements
of smaller gate length and better gate control and vary
less with key electrical parameters.
Imec now presents the 2nd generation of SiGe45% IF-QW pFETs,
processed on standard 300mm STI wafers. Compared to earlier
IF-QW devices, the raised SiGe and Si substrate are recessed
and replaced with a thick SiGe25% epi-layer to form the
source/drain electrodes. Also, imec has developed process
modules that minimize local variations and maximize the
Imec says 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, says Imec.
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, adds Imec.