High accuracy jog CD control on OPC pattern by advanced laser writer Sigma7500

Abstract

With the progress of mask writer technology, 50 KV electron beam writers always perform with better pattern fidelity and critical dimension (CD) control than traditional laser raster-scan writers because laser spot size is confined by the laser longer wavelength relative to electron beam. As far as Optical Proximity Correction (OPC) pattern fidelity is concerned, critical masks with OPC process have to choose Variable-Shape-Beam (VSB) electron beam writer presently.However, the over-aggressive OPC fragmentation induces data volume abrupt explosion, longer writing time, higher mask cost and even mask quality degradation 1 .Micronic Sigma7500 laser writer introduces a novel imaging system combining partial coherent light and DUV spatial light modulation (SLM) to generate a high-quality pattern image 2 . The benefit of raster-scan laser writer is high throughput with consistent writing time regardless of pattern geometry, complexity and data size. However, pattern CD accuracy still needs improvement. This study is to evaluate jog CD control capability of Sigma7500 on OPC typical line-and-space test patterns with different orientations of 0°, 90°, 45° and 135°. In addition, mask CD uniformity and OPC jog height linearity will also be demonstrated.