PHOSPHORUS DEACTIVATION PROCESS IN SILICON SUBMITTED TO HYDROGEN PLASMA

Abstract

C-V measurement is an efficient method to determine the active doping concentration in silicon. In this study, we use it in the aim to understand the process which govern the phosphorus deactivation by hydrogen. To do this, the hydrogenation experiments were carried out in hydrogen plasma generated in an electron cyclotron resonance system (MW-ECR) using microwave power (PMW) for a fixed parameters like hydrogen flux, process time and hydrogenation temperature. The hydrogenation revealed a dopant deactivation due to the formation of phosphorus-hydrogen bonding (PH) as evident from the changes in the doping level after hydrogenation of schottky diode made using FZ-single crystalline silicon. It was also found that deactivation of phosphorus was more pronounced at low microwave plasma power and for samples with low initial phosphorus concentration. On the other hand, the formation of molecular hydrogen below the silicon surface called platelets increase with increasing the initial phosphorus concentration. Therefore, the increase of the average platelets size decreases the density of atomic hydrogen and in turn lowers the effective hydrogen diffusivity