Effect of the flash annealing on the impurity distribution and the electronic structure in the inversion layer

TL;DR

This study investigates how high-temperature flash annealing affects impurity distribution and electronic structure in inversion layers on Si(111), revealing significant changes in band bending and subband energies due to impurity redistribution.

Contribution

It demonstrates the relationship between flash annealing temperature, impurity concentration, and hole subband structure in inversion layers, using ARPES and SIMS analyses.

Findings

High-temperature flash annealing alters impurity profiles in Si(111).

Band bend shape and subband energy separation are affected by impurity redistribution.

Impurity reduction is limited below 900°C during flash annealing.

Abstract

Hole subband structure under strong band bending such a Pb on Si(111) and Indium on Si(111) have been investigated by angle-resolved photoelectron spectroscopy(ARPES). Energy levels of hole subband structure which indicate the quantized levels in inversion layer are strongly depend on band bend shape which can be controlled by the impurity concentration of substrate. Meanwhile, the discrepancy for the suband energy separation between experimental results and calculation results is also observed. In this study, we aim to clarify the relationship between flash annealing and impurity concentration and the hole subband. From this results, it was found out that high temperature flash annealing at 1250 degree has considerable effect on the impurity concentration at subsurface region by Secondary Ion Mass spectroscopy (SIMS) and our diffusion model. This effect makes the band bend shape and subband energy separation change. Moreover, It was revealed that the reduction of the impurity distribution was inhibited less than 900 degree of the flashing temperature.