Double spacer quadruple patterning with self-connected hook-up

Abstract

A photolithographic method for fabricating a pattern which includes a line and a hook-up pad in a semiconductor device, such that the line and the hook-up pad are self-connected to one another by spacer deposition that mitigates a process control issue, and without being misaligned or short circuited. Spacer double patterning lithography can be used. A pattern of sidewall spacer material is formed from a photoresist deposition, conformal spacer material deposition, etching, and removal of the photoresist. A pattern of the sidewall spacer material and a sacrificial layer is formed by performing a further photoresist deposition at a hook-up pad location, a further conformal spacer material deposition, covering part of the sacrificial layer and etching an uncovered part of the sacrificial layer to form a gap. The pattern is transferred to a hard mask layer and then to a wiring layer.