Activation Behavior of Boron and Phosphorus Atoms Implanted in Polycrystalline Silicon Films by Heat Treatment at 250°C

Abstract

The activation behavior of boron and phosphorus implanted into laser-crystallized silicon films were investigated. The ratio of recrystallization of an ion-doping-induced amorphous region by heat treatment at 250°C was 0.35 for a boron concentration lower than 6.4×10 19 cm -3 and 0.5 for a phosphorus concentration lower than 2.5×10 19 cm -3 . This ratio decreased as dopant concentration increased. High electrical conductivities of 1.1×10 2 S/cm and 7.3 S/cm were achieved by oxygen plasma treatment at 250°C for 1 h in the cases of 3.2×10 20 -cm -3 boron and 5.0×10 19 -cm -3 -phosphorus doping, respectively. Numerical analysis of the electrical conductivity revealed that the electrical conductivity was governed by recrystallization ratio and the density of the intrinsic defects of polycrystalline films.