Manufacturing method of semiconductor device having trench type element isolation

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 surrounding the first and second active regions;
• selectively forming a mask layer on the substrate within the first and second active regions;
• forming a trench in the substrate within the isolation region;
• forming a first isolation layer on the trench and the mask layer so that the trench is filled with the first isolation layer and the first isolation layer covers the first and second active regions;
• subjecting the first isolation layer to a chemical mechanical polish so that the mask layer formed within the first active region is exposed while the mask layer formed on the second active region remains covered by the first isolation layer;
• forming a second insulation layer on the exposed mask layer and the first isolation layer;
• subjecting the second insulation layer to the chemical mechanical polish so that mask layer formed within the first and second active regions is substantially exposed;
• and
• forming the semiconductor device having an entire surface that is substantially flat.

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, the first active region is covered by the first material with a first thickness, and the second active region is covered by the first material with a second thickness that is thicker than the first thickness;
• 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.