Feature Article: Recent developments in micromachining of fused silica and quartz using excimer lasers

This issue's Feature Article reports on the current achievements of structuring fused silica and crystal quartz materials on the micrometer scale by excimer laser ablation techniques [1]. It discusses the characteristics of direct ablation as well as the more specialized methods of laser‐induced backside wet etching and laser‐induced plasma‐assisted ablation. As an example of such high‐precision, high‐quality structures, the cover picture shows a set of scanning electron microscopy images of the morphologies of different patterns ablated on quartz substrates by an ArF excimer laser. These micro‐structures were ablated using the 193 nm line of an excimer laser at a fluence of 3.4 J/cm 2 with 100 pulse shots. The cover picture was contributed by Ying‐Tung Chen, Chung Cheng Institute of Technology (Taiwan). The Feature Article is authored by Ampere A. Tseng, who is a professor at the Department of Mechanical and Aerospace Engineering of Arizona State University. His main research interests lie with micro‐ and nanofabrication of various devices and systems. The issue also includes an Editor's Choice article presenting experimental results on laser‐assisted debonding of GaN high electron mobility transistors [2]. The authors show how the laser‐assisted debonding process can be accomplished without compromising the electrical device characteristics or the material defect density.