Process for forming apertures in silicon bodies

DETAILED DESCRIPTION Accordingly, it is an object of this invention to provide an improved process for precisely locating and shaping holes in semiconductor material.
It is a further object of this invention to form an improved process for forming a hole through monocrystalline silicon material wherein the hole has substantially vertical sides.
In accordance with the invention, masking layers are formed on opposite sides of the silicon wafer, opposite registered openings formed in the masking layers, an impurity introduced through the openings into the wafer forming low resistivity regions, depositing a conductor contact on one side of the wafer in contact with the wafer, anodically etching the body through the openings from the opposite side until a region of porous silicon is formed completely through the wafer, and removing the resultant porous semiconductor material with an etchant for semiconductor material.
A preferred process embodiment includes the thermal oxidation of the inner surface of the resultant hole, which provides an insulating layer within the opening.
The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention as illustrated in the accompanying drawings.