Process for producing substrate for liquid ejection head and process for processing silicon substrate

Abstract

A process for producing a substrate for a liquid ejection head in which a depressed portion is formed on a second surface that is a surface opposite to a first surface of a silicon substrate having an element formation region on the first surface with a peripheral side region left, the process including the steps of (1) forming an etching mask layer covering the second surface of the silicon substrate; (2) subjecting the etching mask layer and the silicon substrate to laser abrasion processing to form a pattern opening that does not pass through the silicon substrate; and (3) performing a wet etching process to the silicon substrate where the pattern opening is formed from a side of the second surface to form the depressed portion. The depressed portion is formed over a center side region including a position corresponding to the element formation region.

Dependencies are inferred from the claim text.