Up till now, no productive methods have been used to manufacture a side wall passivation after the individualization of the chips. Any methods associated with side wall passivation, such as oxide deposition, may be complex.
An etch method, such as the so-called Bosch process may be used for etching away unwanted portions of a wafer substrate. A Bosch process is described in Laermer et al., “Method of anisotropically etching silicon” U.S. Pat. No. 5,501,893 granted Mar. 26, 1996, the content of which is hereby incorporated by reference in its entirety. During the Bosch process, a polymer layer may be deposited on the floor and on a side wall of a chip. Following which, an etch process may be carried out wherein the polymer layer on the floor may be fully removed, and the polymer layer on the side wall may be partially thinned. The etching and polymerization process may be alternatingly repeated.
USPTO Backgrounds
USPTO Backgrounds