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. 19, 1995
Filed:
Jul. 07, 1993
Matsushita Electronics Corporation, Osaka, JP;
Abstract
Crystal evaluation apparatus is disclosed which includes a cell region having an anode and a cathode, a reservoir tank for supplying of an aqueous solution for forming an anodic oxide film in the cell region, a reservoir tank for supplying of an aqueous solution for removing the anodic oxide film and a scanning microprobe microscope having a scanning microprobe, installed inside the cell region. A crystal evaluation method is also disclosed which contains anodic oxidation on a semiconductor substrate, removal of an anodic oxide film developed. The semiconductor substrate is observed with a scanning probe microscope having a scanning microprobe. The oxide film is formed on the semiconductor substrate by the anodic oxidation method and then removed by a mixture of hydrofluoric acid and ammonium fluoride. The anodic oxidation method exerts no or little physical impact on the substrate. The hydrofluoric acid and ammonium fluoride mixture removes selectively only the oxide film so that secondary ion implantation defects are exposed to a surface of the substrate. The shape or configuration of the secondary ion implantation defects is observed with an atomic force microscope having a high resolution on the order of nano meter. Therefore, the shape of the defects on the order of nano meter may be observed. In addition, the distribution of impurity concentration over the surface of the substrate may be measured very accurately.