Investigation of Crystal Defects in Epitaxial Layers on Nitrogen-Doped Substrates and a Method for their Suppression

摘要

Crystal defects in epitaxial layer on nitrogen-doped Czochralski-grown Silicon (CZ-Si) substrate was investigated by confocal laser inspection system and transmission electron microscope. It was found that typical crystal defects, such as stacking fault and perfect dislocation pair, are generated in epitaxial layer on the nitrogen-doped CZ-Si substrate. These defects are induced by the propagation of grown-in defects in nitrogen-doped CZ-Si substrate. The dependence of epitaxial layer defect formation on the quality of substrates was investigated. As a result, following two methods were revealed to be effective for the suppression of epitaxial layer defect: (1) control of grown-in defect distribution by nitrogen concentration and crystal growth parameter V/G; (2) carbon co-doping in addition to nitrogen doping.