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. 20, 2003
Filed:
Aug. 06, 2001
Applicant:
Inventors:
Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L 2/1336 ; H01L 2/176 ; H01L 2/900 ;
U.S. Cl.
CPC ...
H01L 2/1336 ; H01L 2/176 ; H01L 2/900 ;
Abstract
The present invention provides a formation method of a trench structure comprising forming a pad oxide layer on a substrate. A first polysilicon layer is formed on the pad oxide layer and an oxide layer is formed thereon. A second polysilicon layer is formed on the oxide layer. The partial second polysilicon layer, the oxide layer, the first polysilicon layer, and the pad oxide layer are removed to expose the partial substrate. The second polysilicon layer and the partial substrate are etched for forming the trench structure in the substrate. An etched depth of the trench structure is well controlled by the etched thickness of the second polysilicon layer.