Directional Etch Mask in Single Layer Resist
Original Publication Date: 1983-Oct-01
Included in the Prior Art Database: 2005-Feb-07
This article describes a process for making a resist mask using a single layer of positive resist that is suitable for directional etching of micron and submicron lines. The resist is surface hardened and then E-beam exposed at a sufficiently high dose to completely undercut the resist lines. The resulting resist lines may or may not be fully suspended depending on their width and the dose used. In prior-art processes, single layer resists have been used to perform like double layer resists through a surface hardening technique which resulted in a different solubility in the developer between the upper layer and the remainder of the material. This provided undercut profiles which have been used, for example, in metal lift-off.