The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 17, 2005
Filed:
Dec. 05, 2001
Peggy J. Clews, Tijeras, NM (US);
Seethambal S. Mani, Albuquerque, NM (US);
Peggy J. Clews, Tijeras, NM (US);
Seethambal S. Mani, Albuquerque, NM (US);
Sandia Corporation, Albuquerque, NM (US);
Abstract
An etching composition and method is disclosed for removing an oxide sacrificial material during manufacture of semiconductor devices including micromechanical, microelectromechanical or microfluidic devices. The etching composition and method are based on the combination of hydrofluoric acid (HF) and sulfuric acid (HSO). These acids can be used in the ratio of 1:3 to 3:1 HF:HSOto remove all or part of the oxide sacrificial material while providing a high etch selectivity for non-oxide materials including polysilicon, silicon nitride and metals comprising aluminum. Both the HF and HSOcan be provided as 'semiconductor grade' acids in concentrations of generally 40-50% by weight HF, and at least 90% by weight HSO.