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:
Jun. 04, 1991
Filed:
Oct. 31, 1989
Shinya Akamine, Stanford, CA (US);
Calvin F Quate, Stanford, CA (US);
The Board of Trustees of the Leland Stanford Junior University, Stanford, CA (US);
Abstract
Apparatus and method for forming a microfabricated cantilever with a single crystal, integral silicon tip on a nitride cantilever. A nitride-silicon-nitride sandwich structure is patterned and etched to form a cantilever structure, exposing sidewall portions of the silicon layer. The exposed sidewall portions of the silicon layer are oxidized to form oxide sidewalls. The top nitride layer is removed and the silicon layer is anisotropically etched and removed except fo a tetrahedral silicon tip formed on the rear nitride layer. The tetrahedral silicon tip has one exterior surface bounded by a (111) plane with two additional exterior surfaces bounded by the oxide sidewall. The oxide sidewall is removed to provide a tetrahedral silicon tip at the free end of the nitride cantilever. Alternative cantilever materials such as polysilicon and deposited oxide can be substituted for nitride. Doping the surface region of the cantilever form a P-N junction which provides a stop for electrochemical anisotropic etching of the silicon layer when an electrical potential is applied across the P-N position.