Low cost shallow trench isolation using non-conformal dielectric material

A method for planarizing a trench region provided in a semiconductor substrate, the method comprising:

• depositing a pad material on a non-trench region of said semiconductor substrate;
• forming at least one trench region in said semiconductor substrate;
• applying a filler material by high density plasma method in the trench region and on the semiconductor substrate;
• separating adjacent sections of said trench region and a non-trench region of filler material by at least a gap of exposed underlying pad material;
• and
• removing only said filler material which is not provided in said trench region.

A method of forming a planarized structure on a semiconductor substrate, the method comprising:

• depositing a pad material on said semiconductor substrate;
• forming a trench region and non-trench regions on said semiconductor substrate;
• depositing filler material by high density plasma method on said trench region and said non-trench regions, said filler material filling said trench region to a predetermined height;
• separating adjacent sections of said trench region and said non-rench region of filler material by at least a gap of exposed underlying material;
• and
• removing said filler material from said non-trench regions while allowing said filler material in said trench region to remain filled to the predetermined height.