Methods for forming an integrated circuit with straightened recess profile

摘要

Methods are provided for forming an integrated circuit. In an embodiment, the method includes forming a sacrificial mandrel overlying a base substrate. Sidewall spacers are formed adjacent sidewalls of the sacrificial mandrel. The sidewall spacers have a lower portion that is proximal to the base substrate, and the lower portion has a substantially perpendicular outer surface relative to the base substrate. The sidewall spacers also have an upper portion that is spaced from the base substrate. The upper portion has a sloped outer surface. A first dielectric layer is formed overlying the base substrate and is conformal to at least a portion of the upper portion of the sidewall spacers. The upper portion of the sidewall spacers is removed after forming the first dielectric layer to form a recess having a re-entrant profile in the first dielectric layer. The re-entrant profile of the recess is straightened.