SOI substrate processing method

Abstract

An object of this invention is to provide a substrate processing method capable of satisfactorily performing in etching in the step of removing a porous silicon layer by etching. In order to achieve this object, a substrate processing method includes the anodizing step of forming a porous silicon layer on a major surface of a single-crystal silicon substrate, the silicon film formation step of growing a single-crystal silicon film on the porous silicon layer, the removal step of bonding a first substrate obtained by oxidizing a surface of the single-crystal silicon film to a second substrate as a supporting substrate, and removing a single-crystal silicon portion from a lower surface side of the first substrate to expose the porous silicon layer, and the etching step of etching the exposed porous silicon layer to remove the porous silicon layer on the single-crystal silicon film, wherein in washing after the anodizing step, a time in which the first substrate is removed from the electrolytic solution and exposed to the air until washing is limited to a range in which the porous silicon layer is prevented from remaining on the single-crystal silicon film in the etching step.

Dependencies are inferred from the claim text.