A novel approach of chemical mechanical polishing for cadmium zinc telluride wafers

Zhenyu Zhang; Bo Wang; Ping Zhou; Renke Kang; Bi Zhang; Dongming Guo

doi:10.1038/srep26891

A novel approach of chemical mechanical polishing for cadmium zinc telluride wafers

Sci Rep. 2016 May 26:6:26891. doi: 10.1038/srep26891.

Authors

Zhenyu Zhang^{1

2

3}, Bo Wang¹, Ping Zhou¹, Renke Kang¹, Bi Zhang^{1

4}, Dongming Guo¹

Affiliations

¹ Key Laboratory for Precision and Non-Traditional Machining Technology, Ministry of Education, Dalian University of Technology, Dalian 116024, China.
² Changzhou Institute of Dalian University of Technology, Changzhou 213164, China.
³ State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, China.
⁴ Department of Mechanical Engineering, University of Connecticut, Storrs, CT 06269, USA.

Abstract

A novel approach of chemical mechanical polishing (CMP) is developed for cadmium zinc telluride (CdZnTe or CZT) wafers. The approach uses environment-friendly slurry that consists of mainly silica, hydrogen peroxide, and citric acid. This is different from the previously reported slurries that are usually composed of strong acid, alkali, and bromine methanol, and are detrimental to the environment and operators. Surface roughness 0.5 nm and 4.7 nm are achieved for Ra and peak-to-valley (PV) values respectively in a measurement area of 70 × 50 μm(2), using the developed novel approach. Fundamental polishing mechanisms are also investigated in terms of X-ray photoelectron spectroscopy (XPS) and electrochemical measurements. Hydrogen peroxide dominates the passivating process during the CMP of CZT wafers, indicating by the lowest passivation current density among silica, citric acid and hydrogen peroxide solution. Chemical reaction equations are proposed during CMP according to the XPS and electrochemical measurements.

Publication types

Research Support, Non-U.S. Gov't