Effect of the Hydrogen Peroxide on the Ti_0.4Sb₂Te₃Chemical Mechanical Polishing in Acidic Slurry

Abstract

In this work, chemical mechanical polishing (CMP) of Ti0.4Sb2Te3 (TST) was investigated in the presense of hydrogen peroxide (H2O2) as an oxidizer. The polishing rate of TST reached a maximum at 0.5 wt% H2O2 concentration and then decreased with a further increase in H2O2 concentration. The eletrochemical techniques were applied to investigate the passivation behabivor of the TST under static conditons at pH 2.3 with varying H2O2 concentrations. The TST static etched surface morphology indicated that there were strong chemical reactions taking place between TST surface and H2O2 at 0.5 wt% H2O2 concentration. With the H2O2 concentration further increasing, the chemical reactions were inhibited by the passivation behavior, which was obtained using eletrochemical techniques. In addition, the surface compounds of the TST in the presence of H2O2 were analyzed by the X-ray photoelectron spectroscope (XPS). Finally, Atomic Force Microscope (AFM) was used to characterize the surface quality after CMP. By combining the experimental results, we proposed a possible mechanism of TST in the presence of H2O2.

Influence of Polishing Parameters on Abrasive Free Chemical Mechanical Planarization (AFCMP) of Non-Polar (11-20) and Semi-Polar (11-22) GaN Surfaces

“…[3][4] To avoid this problem, GaN based devices grown along non-polar and semi-polar directions are getting increasing attention of the scientific community. [5][6][7] Non-polar (11)(12)(13)(14)(15)(16)(17)(18)(19)(20) and semi polar GaN (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) faces { (11)(12)(13)(14)(15)(16)(17)(18)(19)(20) and (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) represents the miller indexes (hkil) of the crystal planes for hexagonal GaN crystal structure in four coordinate axis scheme} are generally grown hetero-epitaxially on miscut r-plane and mplane s...…”

“…Therefore, use of nanoparticle abrasive containing slurries in CMP process is not economic. 19 The purpose of this study is to investigate the effect of abrasive free CMP on the MRR and surface quality of semi-polar (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) and non-polar (11)(12)(13)(14)(15)(16)(17)(18)(19)(20) GaN surfaces.…”

“…In this work a novel single step, abrasive-free CMP (AFCMP) process, using proprietary slurry chemistry and processing parameters, has been investigated to polish non-polar (11)(12)(13)(14)(15)(16)(17)(18)(19)(20) and semipolar (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) GaN epilayers grown on 2 inch sapphire wafers. This AFCMP process is an efficient, relatively low damage causing and cost effective surface planarization method for non-polar (11)(12)(13)(14)(15)(16)(17)(18)(19)(20) and semi-polar (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) GaN surfaces. Also, the post-CMP cleaning becomes relatively easier since the polishing slurry does not contain any abrasive particles that may remain on the surface after polishing.…”

“…In the present investigation, we report on the comparative study of CMP processes carried out on non polar (11)(12)(13)(14)(15)(16)(17)(18)(19)(20) and semi-polar (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) GaN surfaces using AFCMP. The effect of AFCMP process parameters, such as type and concentration of oxidizer, polishing pressure, platen velocity, and slurry pH, on the material removal rate (MRR) and surface finish of non-polar (11)(12)(13)(14)(15)(16)(17)(18)(19)(20) and semi-polar (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) GaN surfaces has been reported. To the best of our knowledge there is no report, in the open literature, on AFCMP of non-polar (11)(12)(13)…”

“…The effect of AFCMP process parameters, such as type and concentration of oxidizer, polishing pressure, platen velocity, and slurry pH, on the material removal rate (MRR) and surface finish of non-polar (11)(12)(13)(14)(15)(16)(17)(18)(19)(20) and semi-polar (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) GaN surfaces has been reported. To the best of our knowledge there is no report, in the open literature, on AFCMP of non-polar (11)(12)(13)(14)(15)(16)(17)(18)(19)(20) and semi-polar (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) GaN surfaces using KMnO 4 as oxidizer. KMnO 4 , most likely, oxidizes the non-polar (11)(12)(13)…”