Determination of conduction type in high-resistivity silicon by combining spreading resistance profiling (SRP) with hydrofluoric acid treatment

Abstract

The effect of hydrofluoric acid (HF) treatment on the surface electrical properties was observed in high-resistivity bulk silicon by the spreading resistance profiling (SRP) technique. It is found that the near-surface resistivity decreased in n-type silicon and increased in p-type silicon after HF treatment according to the SRP measurement. The variation of surface chemical elements and energy bands of HF-treated n-type and p-type (100) silicon has been characterized by x-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy measurements. The results indicate that the surface Fermi level is shifted toward the conduction band minimum after HF treatment. The surface energy band bending caused by the surface electronegative groups (–F and –OH) was investigated by the method of First-principles calculation. Based on these findings, a method combining the SRP measurement with HF treatment to determine the conduction type of high-resistivity silicon was proposed, which is critical for the development of high-resistivity CZ silicon crystal growth.