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. 29, 2005
Filed:
Jun. 12, 2002
Yi-lin Chen, Hsin-Chu, TW;
Yi-Lin Chen, Hsin-Chu, TW;
Taiwan Semiconductor Manufacturing Company, Hsin-Chu, TW;
Abstract
A new method is provided for the creation of an alignment mark. V-groove etching is applied whereby this anisotropic etch stops at the (1,1,1) crystal direction of the silicon of the substrate. The invention applies a wet etchant to the surface of monocrystalline silicon of the silicon substrate by using a solution containing a mixture of potassium hydroxide (KOH) or NHor tetramethyl ammonium hydroxide (TMAH). This solution anisotropically etches the silicon substrate, forming grooves in the substrate having sidewalls that are sloped at an angle of about 54 degrees with the horizontal. The slope of the sidewalls is a function of the different etch rates of monocrystalline silicon along the different crystalline orientations. The surface of the substrate represents <100> planes of the silicon, which etches faster than the sloped sidewalls that represent the <111> plane. The KOH/NH/TMAH etch stops on the <111> plane of the silicon substrate.