Methods of forming polished material and methods of forming isolation regions

Abstract

In one aspect, the invention encompasses a method of forming a polished material. A substrate is provided and an elevational step is provided relative to the substrate. The elevational step has an uppermost surface. A material is formed beside the elevational step. The material extends to above the elevational step uppermost surface and has lower and upper layers. The lower layer polishes at slower rate than the upper layer under common polishing conditions. The lower layer joins the upper layer at an interface. The material is polished down to about the elevational level of the elevational step uppermost surface utilizing the common polishing conditions. In another aspect, the invention encompasses a method of forming an isolation region. A substrate is provided. The substrate has an opening extending therein and a surface proximate the opening. A material is formed within the opening. The material extends to above the substrate surface, and comprises a lower layer and an upper layer. The lower layer is more dense than the upper layer, and joins the upper layer at an interface that extends to at or below an elevational level of the substrate surface. The material is polished at least down to about the elevational level of the substrate surface.