Hole confinement and 1/f noise characteristics of SiGe double-quantum-well p-Type metal-oxide-semiconductor field-effect transistors
Journal
Japanese Journal of Applied Physics Part1
Journal Volume
45
Journal Issue
5 A
Pages
4006-4008
Date Issued
2006
Author(s)
Abstract
A working p-type SiGe double-quantum-well metal�Voxide�Vsemiconductor field effect transistor (DQW-pMOSFETs) has been fabricated and characterized. The upper quantum well with 15%-Ge acts as an induced-carrier buffer to slow holes into the Si surface channel and increases the number of high-mobility holes in the 30%-Ge well at the bottom under high gate voltage by improving carrier confinement. DQW devices with a thinner Si-spacer layer between the two SiGe quantum wells exhibit an improved effective hole mobility and wider gate voltage swings but also reduced 1/ f noise levels than Si-controlled pMOSFETs. The DQW has an enhanced carrier confinement compared to a single quantum-well (SQW) device; however, the degradation of mobility and transconductance observed in a sample DQW indicates that this poor transport mechanism may result from an additional hole scattering effect at the Si/SiGe interface.
Type
journal article