Indexed by:期刊论文

Date of Publication:2010-02-15

Journal:APPLIED SURFACE SCIENCE

Included Journals:SCIE、EI

Volume:256

Issue:9

Page Number:2691-2699

ISSN No.:0169-4332

Key Words:MgO single crystal substrate; Chemical mechanical polishing; Chemical etching; Pit

Abstract:Magnesium oxide (MgO) single crystal is an important substrate for high temperature superconductor, ferroelectric and photoelectric applications. The function and reliability of these devices are directly affected by the quality of polished MgO surface because any defect on the substrate, such as pit or scratch, may be propagated onto device level. In this paper, chemical mechanical polishing (CMP) experiments were conducted on MgO (1 0 0) substrate using slurry mainly comprised of 1-hydroxy ethylidene-11-diphosphonic acid (HEDP) and silica or ceria particles. Through monitoring the variations of the pits topography on substrate surface, generation and removal mechanism of the pits were investigated. The experimental results indicate that the pits were first generated by an indentation or scratch caused by particles in the slurry. If the rate of chemical etching in the defect area is higher than the material removal rate, the pits will grow. If chemical reaction in the defect area is slower than the material removal rate, the pits will become smaller and eventually disappear. Consequently, these findings may provide insight into strategies for minimizing pits during CMP process. (C) 2009 Elsevier B. V. All rights reserved.