Boosting n-Type Doping Levels of Ge With Co-Doping by Integrating Plasma-Assisted Atomic Layer Deposition and Flash Annealing Process

Abstract

To achieve a high concentration of dopants over 1 x 10(20) cm(-3) on germanium (Ge), co-doping with phosphorus (P) and antimony (Sb) by plasma assisted atomic layer deposition (PALD) and a subsequent annealing process [rapid thermal annealing process (RTP) or flash lamp annealing process (FLP)] are proposed and investigated. We found that the PALD stacked co-doping (POx/SiOy and Sb-2 O-5) films were uniformly deposited. Using the conventional RTP method led to a low doping concentration (<3 x 10(19) cm(-3)). However, FLP with a Xenon (Xe) lamp (lamp duration: 3 ms; energy density: 56 J/cm(2)) raised the surface temperature to nearly 800 degrees C. Furthermore, high concentrations of both P and Sb (>1 x 10(20) cm(-3)) were achieved at the surface. Our findings suggest that the FLP with high energy in a short amount of time (similar to 3 ms) can create the peak power effect and the co-doping effect. The evidence shows that these effects contribute to enhancing n-type doping levels in the Ge structure.