SiGe pMOSFETs 의 저온 초고주파 특성 연구

In this paper, RF and DC characteristics of SiGe/Si channel pMOSFETs at low temperature are reported. The 180 ㎚-gate-length SiGe pMOSFETs at 77 K shows 22 % improvement of the transconductance(g m ) and 27 % improvement of the current gain cutoff frequency(f T ) compared with that at 300 K. This improvement is about 6 % and 14 % higher than that of Si pMOSFETs, respectively. As the temperature decreases, the effect of surface roughness scattering is dominated due to reduction of lattice scattering. Because SiGe/Si heterojunction pMOSFETs have a buried channel, the roughness scattering in a SiGe/Si channel is smaller than that in a Si channel.