US Patent:
20010053583, Dec 20, 2001
Inventors:
Simon Fang - Richardson TX, US
Stanton Ashburn - McKinney TX, US
International Classification:
H01L021/76
US Classification:
438/424000, 438/435000, 438/430000
Abstract:
An embodiment of the instant invention is a method of forming an isolation structure within a semiconductor structure so as to provide isolation between two electronic devices, the method comprising: forming trenches in the semiconductor structure, the trenches having a top and a bottom, and a first portion of the trenches having a narrow bottom and a second portion of the trenches having an extended bottom; forming a filler material (of FIG. ) in the trenches, the filler material filling the first portion of trenches to a first height and filling the second portion of trenches to a second height which is less than the first height thereby resulting in a stepped down portion of the filler material in the second portion of trenches; forming a planar layer on the filler material using a first material (of FIG. ), the planar layer having a substantially planar top surface; removing the top portion of the planar material using a first removal agent which removes the first material more readily than the filler material, this step resulting in a substantially planar top surface formed substantially of the filler material over the first portion of the trenches and the first material over the second portion of the trenches; and removing the portions of the filler material and the first material which overlie the top of the trenches, the step of removing the portions of the filler material and the first material removes the filler material at about the same rate as the removal of the first material.
