Spacer formation for graded dopant profile having a triangular geometry

摘要

The formation of a spacer for a graded dopant profile having a triangular geometry is disclosed. In one embodiment, a method has three steps. In the first step, a gate is formed on a substrate, the gate having two edges. In the second step, at least one spacer is formed, where each spacer is adjacent to an edge of the gate and has a triangular geometry. In the third step, an ion implantation is applied to form a graded lightly doped region within the substrate underneath each spacer, the region corresponding to the triangular geometry of the spacer.