Spinel wafers and methods of preparation

US7919815B1 · kind B1 · utility

Assignee

• SAINT-GOBAIN CERAMICS & PLASTICS, INC. · US

Inventors

• Brahmanandam V. Tanikella · Northborough, US
• Elizabeth THOMAS · New Milford, US
• Frank L. Csillag · Hopkinton, US
• Palaniappan Chinnakaruppan · Springboro, US
• Jadwiga Jaroniec · Stow, US
• Eric Virey · Portland, US
• Robert A. Rizzuto · Worcester, US

Key dates

• Filing date: Mar 1, 2006
• Grant date: Apr 5, 2011
• Expiry date: Nov 23, 2029

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S438/974

Abstract

Wafer suitable for semiconductor deposition application can be fabricated to have low bow, warp, total thickness variation, taper, and total indicated reading properties. The wafers can be fabricated by cutting a boule to produce rough-cut wafers, lapping the rough-cut wafers, etching the lapped wafers to remove a defect, deformation zone and relieve residual stress, and chemically mechanically polishing the etched wafers to desired finish properties. Etching can be performed by immersion in a heated etching solution comprising sulfuric acid or a mixture of sulfuric and phosphoric acids. A low pH slurry utilized in chemical mechanical polishing of the spinel wafer can comprise α-Al2O3 and an organic phosphate.