Notable difference between rapid-thermal and microwave annealing on Ge pMOSFETs

Abstract

Effects of rapid-thermal-annealing (RTA) and microwave annealing (MWA) on Ge pMOSFET with GeOx interfacial layer (IL) and HfO2 gate dielectric were studied in this work. High gate leakage and low hole mobility may be induced by the diffusion of GeOx during RTA thermal process. A high hole mobility of ~510 cm2/V-s, low equivalent oxide thickness (EOT) of ~0.7 nm, and very low gate leakage density of ~10−4 A/cm2 at V = VFB + 1 V in Ge pMOSFET can be simultaneously achieved with the efficient annealing effects of MWA on hydrogen plasma (H*) treated GeOx IL due to the suppression of GeOx out-diffusion. The notable difference between RTA and MWA can be attributed to good annealing effects on gate stack by using a MWA with low effective thermal budget.