Impact of metal–oxide gate dielectric on minority carrier lifetime in silicon

Abstract

Using a deposition followed by high-temperature drive in, we have examined the impact of metalorganic chemical vapor deposition (MOCVD) HfO2, MOCVD ZrO2, and physical vapor deposition (PVD) ZrxSi1−xO2 gate dielectrics on the minority carrier lifetime. The lifetime measurement utilized electrolytical metal tracer (ELYMAT)™. The minority carrier lifetime in Si after a 1025 °C anneal is comparable for HfO2 and the SiO2 control. The ELYMAT™ data showed similar results for the MOCVD ZrO2. However, a highly reduced lifetime was measured for the PVD ZrxSi1−xO2 films due to the presence of significant levels of Fe and Ni in the PVD Zr-silicate wafers as detected by VPD-TXRF. Thus, we saw no impact on minority carrier lifetime in Si for the HfO2 and ZrO2 formed by MOCVD methods, while there was a major impact on minority carrier lifetime in Si for the ZrxSi1−xO2 produced by the PVD method.