Record number :
1000241
Title of article :
Chemical mechanical polishing (CMP) anisotropy in sapphire
Author/Authors :
Honglin Zhu، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2004
Pages :
11
From page :
120
To page :
130
Abstract :
The polishing removal rate and surface quality of sapphire (Al2O3) varies greatly with crystal orientation when chemical effects couple with abrasive removal in chemical mechanical polishing (CMP). The relationship of orientation, solution chemistry and abrasive were studied for sapphire with c (0 0 0 1), a (1 1 2 0), and m (1 0 1 0) orientations. Aqueous abrasive slurries of alumina, monocrystalline diamond, and polycrystalline diamond were compared at various pH’s. Orientationdependent removal rate as determined by weight loss was greatest for the c (0 0 0 1) orientation, with a remarkably high removal rate of 1.0 mg/h for alumina slurry at pH 12. Surface quality was characterized with atomic force microscopy (AFM) in terms of RMS roughness and scratch depth. The optimum CMP removal by alumina also yielded a superior surface finish of 0.3 nm RMS roughness. Results are examined in light of atomic structure and hydration layer formation. It is proposed that the a-alumina abrasives experience surface hydration similar to sapphire, and a chemical–mechanical reaction between the sapphire and the aalumina abrasive hydration layers promotes accelerated material removal.
Keywords :
Sapphire , Anisotropy , AFM , c (0 0 0 1) orientation , m (1 0 10)orientation , alumina , Diamond , Chemical mechanical polishing (CMP) , a (1 1 2 0) orientation
Journal title :
Applied Surface Science
Journal title :
Applied Surface Science
Serial Year :
2004
Link To Document :
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