摘要 |
A semiconductor device is formed with sub-resolution features and at least one additional feature having a relatively larger critical dimension using only two masks. An embodiment includes forming a plurality of first mandrels, having a first width, and at least one second mandrel, having a second width greater than the first width, overlying a target layer using a first mask, forming sidewall spacers along the length and width of the first and second mandrels, forming a filler adjacent each sidewall spacer, the filler having the first width, removing the filler adjacent sidewall spacers along the widths of the first and second mandrels using a second mask, removing the sidewall spacers, and etching the target layer between the filler and the first and second mandrels, thereby forming at least two target features with different critical dimensions. Embodiments further include using a third mask to form a semiconductor device having further features with a different critical dimension, but the same pitch, as the sub-resolution features. |