Patent ID: 7250336
Filing Date: 2007-07-31
Classification: B81B,B81C,H01L,Y10S

Abstract:
1. A method for fabricating a shadow mask in a trench of a microelectronic or micromechanical structure, comprising: providing a trench in the microelectronic or micromechanical structure; providing a partial filling in the trench; providing a first liner mask layer on the partial filling; providing a sacrificial filling on the liner mask layer to completely fill the trench; shallow etching back of the sacrificial filling into the trench; forming a first mask on a top side of the sacrificial filling in the trench by a shadow mask process; removing a subregion of the sacrificial filling in the trench using the first mask; and optionally removing a subregion of the first liner mask layer below it on the partial filling, a remaining subregion of the sacrificial filling in the trench serving as a second mask, wherein the first mask is formed by: carrying out an oblique implantation to modify the etching rate of a subregion at the top side of the sacrificial filling in the trench for a predetermined etching process; selectively recessing the subregion or the complementary subregion at the top side of the sacrificial filling in the predetermined etching process; filling the selectively recessed subregion or complementary subregion with at least a third liner mask layer; and leveling the filled subregion or complementary subregion so as to be flush with the top side of the sacrificial filling.