Pattern Transfer Characterization after Double-Level Lithography for a Fabrication of the Three-Dimensional Aluminum Titanium Carbide Air Bearing Surface of the Hard Disk Slider

Abstract

The transfer characteristics of the three-dimensional (3D) photoresist (PR) pattern to the aluminum titanium carbide (AlTiC) layer made for an air bearing surface (ABS) using the double-level lithography process and reactive ion etching (RIE) is investigated. The simulated process windows for single-level (conventional) and double-level lithography provide the process conditions to obtain desired PR thicknesses. The PR pattern with the underneath AlTiC layer is then etched with the designed recipe that consists of three consecutive etchings using CF4, O2, and CF4, respectively. The triple-step pattern is successfully formed on the AlTiC layer. The nonlinear relationship of the cumulative exposure and the PR thickness is believed to contribute to a decrease in etch selectivity of PR:AlTiC on the double-exposure area with the cumulative exposure.