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. 08, 1988
Filed:
Jul. 21, 1986
Applicant:
Inventor:
Howard K Leung, Austin, TX (US);
Assignee:
Motorola, Inc., Schaumburg, IL (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B44C / ; H01L / ;
U.S. Cl.
CPC ...
156643 ; 156646 ; 156648 ; 156651 ; 1566591 ; 156662 ;
Abstract
A process having three steps to etch a vertical trench with rounded top corners and rounded bottom corners. The first step involves anisotropically etching a vertical trench through an opening in a masking layer to approximately 85 to 90% of the final trench depth to give a trench with sharp or abrupt top corners and sharp bottom corners. The second step rounds the top corners and the third step extends the trench depth and provides rounded bottom corners. Using CHF.sub.3 as an etch species and adjusting the DC bias differently for each step gives better profile control and better critical dimension (CD) control.