Patent ID: 8652933

Claim:
A method of forming a semiconductor device structure in a semiconductor layer comprising: forming a first trench of a first width and a second trench of a second width in the semiconductor layer; depositing a conformal liner in the first trench and the second trench, the conformal liner conforming to a wall of the first trench and a wall of the second trench; depositing a layer of first material on the conformal liner which conforms to the wall of the first trench but does not fill it and which fills the second trench; removing the first material completely from the first trench while simultaneously recessing the first material in the second trench, the first material remaining in the second trench except for a recess formed at a top of the second trench as a result of the recessing the first material; removing the conformal liner completely from the first trench while simultaneously partially removing the conformal liner from the second trench within the recess; depositing a second material into and filling the first trench and over a top of the first material in the second trench to fill the recess in the second trench with the first material; and uniformly removing the second material from the top of the first material in the second trench, wherein the first trench is filled with the second material and the second trench is filled with the first material and wherein the first material is different from the second material.