Patent ID: 8338305

Claim:
A method of forming a multi-fin device, the method comprising: forming, on a semiconductor substrate, a patterned mask layer that includes a first opening having a first width W 1 and a second opening having a second width W 2 less than the first width, thereby defining a multi-fin device region and an inter-device region, wherein the inter-device region is aligned with the first opening; and the multi-fin device region includes at least one intra-device region being aligned with the second opening; forming a material layer on the semiconductor substrate and the patterned mask layer, wherein the material layer substantially fills in the second opening; performing a first etching process self-aligned to remove the material layer within the first opening such that the semiconductor substrate within the first opening is exposed; performing a second etching process to etch the semiconductor substrate within the first opening, and to form a first trench in the inter-device region; and performing a third etching process to remove the material layer in the second opening.