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:
Mar. 19, 2002
Filed:
Jul. 28, 1999
Applicant:
Inventors:
Daniel Scott Marshall, Chandler, AZ (US);
Lucia R. Salem, Gilbert, AZ (US);
Harland G. Tompkins, Chandler, AZ (US);
Assignee:
Motorola, Inc., Schaumburg, IL (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B44C 1/22 ;
U.S. Cl.
CPC ...
B44C 1/22 ;
Abstract
A method of etching a layer of electrical insulating material including a layer of strontium titanate on a surface of a semiconductor substrate. The layer of strontium titanate is immersed in a passivated etching solution including an acid and HF and focused light is directed onto the surface of the layer of strontium titanate at areas to be etched, so as to depassivate the passivated surface and to etch the layer of strontium titanate only at the surface receiving collimated light. In a preferred embodiment, the passivated etching solution includes HCl and less than 1000 ppm of HF.