Patent ID: 7256100

Claim:
A method of manufacturing a semiconductor device, comprising: providing a semiconductor substrate including a first active region having a first area, a second active region having a second area that is larger than the first area and an isolation region; selectively forming a mask layer on the first and second active regions of the substrate; forming a trench on the isolation region of the substrate; depositing a first isolation material on the trench and the mask layer so that the trench is filled with the first material and the first material covers the first and second active regions; subjecting the first material to a chemical mechanical polish so that the mask layer formed on the first active region is exposed while the mask layer formed on the second active region remains covered by the first material; depositing a second insulation material on the exposed mask layer and the first material; subjecting the second material to the chemical mechanical polish so that mask layer formed on the first and second active regions is substantially exposed; and forming the semiconductor device having an entire surface that is substantially flat.