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:
Dec. 29, 1998
Filed:
Aug. 15, 1996
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
According to the present invention, to flatten the surface of a silicon substrate by polishing an element isolating buried insulation film by chemical mechanical polishing, a polysilicon film is formed on the top surface of a projection of a silicon substrate. After that, a buried insulation film is formed all over the silicon substrate along the irregularities thereof. A carbon film is formed on the surface of a recess of the buried insulation film. Using the carbon film as a stopper, the buried insulation film is polished by the chemical mechanical polishing to ease the irregularities of the surface of the polished insulation film. Then the carbon film is removed and, using the polysilicon film as a stopper, the buried insulation film is polished by the chemical mechanical polishing to flatten the surface of the polished insulation film. Thus, the flatness of the buried insulation film can easily be controlled, and the surface of the silicon substrate can always be flattened satisfactorily.