Self-aligned imprint lithography for top-gate amorphous silicon thin-film transistor fabrication

Abstract

We developed self-aligned imprint lithography (SAIL) for top-gate amorphous silicon (a-Si) thin-film transistors (TFTs). Our SAIL process enables a device pattern definition in a single imprint step that uses a three-level mold. The various levels of the mold are defined by a stepwise opening of a chromium hardmask and subsequent dry-etching. For TFT fabrication we imprint, and consecutively etch the imprint resist levels and device layers. The imprinted top-gate a-Si TFTs have nickel silicide source/drain self-aligned to the gate with mobilities of ∼0.4 cm2/V s.