A. Nishiyama et al., FORMATION OF SIGE SOURCE DRAIN USING GE IMPLANTATION FOR FLOATING-BODY EFFECT RESISTANT SOI MOSFETS, JPN J A P 1, 35(2B), 1996, pp. 954-959
SiGe was formed by Ge implantation into silicon on insulator (SOI) sub
strates with the dosage range from 0.5 to 3 x 10(16) cm(-2) and subseq
uent annealing in N-2. The implantation dosage dependence of the cryst
alline quality bandgap and sheet resistance of the SiGe layers are inv
estigated. The implantation damage for Ge dosage up to 1 x 10(16) cm(-
2) can be removed at a temperature as low as 700 degrees C. A SiGe cry
stalline network is formed by the annealing at the same time. With a G
e dosage of 1 x 10(16) cm(-2) or more, bandgap narrowing of the SiGe l
ayer was detected. Sheet resistances of SiGe N+ and P+ layers graduall
y increase for higher Ge dosage. SOI MOSFET characteristics in terms o
f the floating-body effect with the SiGe source/drain layers are prese
nted. The bandgap narrowing suppresses the floating-body effect of ful
ly depleted SOI MOSFETs, while maintaining the reverse leakage current
of the p-n junction between the source/drain and channel at a low lev
el.