Patent ID: 7473615
Filing Date: 2009-01-06
Classification: H01L

Abstract:
1. A semiconductor processing method, comprising: providing a semiconductor substrate having a patterned mask thereover: forming a trench in the substrate proximate the mask: after forming the trench, laterally recessing the mask: oxidizing the substrate utilizing an oxidant in the presence of hydrogen to form an oxide structure between the trench and the laterally-recessed mask: depositing insulative material within the trench and over the oxide structure: while at least some of the oxide structure remains, replacing at least a portion of the mask with at least a portion of a transistor gate stack: wherein the mask comprises a first layer that contains silicon nitride over a second layer that contains silicon dioxide; and wherein the lateral recessing of the mask comprises first lateral recessing of the first layer with a first etchant, and subsequent lateral recessing of the second layer with a second etchant that is different from the first etchant.