Epitaxial growth pretreatment method of deep hole structure

The invention provides an epitaxial growth pretreatment method of a deep hole structure, which comprises the following steps: providing a substrate, and etching the substrate to form the deep hole structure; within two hours after etching, utilizing etching gas ammonium fluoride (NH4F) and ammonium hydrogen fluoride (NH 4F. HF) to pretreat the deep hole structure so as to remove natural oxide layers on the side wall and the bottom of the deep hole structure; forming an epitaxial layer in the deep hole structure by adopting epitaxial growth; and judging the growth quality of the epitaxial layer and the contour condition of the deep hole structure through FA slicing and SEM data. In the pretreatment before the epitaxial growth of the deep hole structure, the etching gases NH4F and NH4F.HF are used for replacing the traditional wet process liquid medicine, the treatment on the natural oxide layers on the side wall and the bottom of the deep hole structure is better, a good foundation is laid for subsequent epita