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:
Jul. 31, 1984
Filed:
Feb. 17, 1983
Masahiro Abe, Yokohama, JP;
Toshio Yonezawa, Yokosuka, JP;
Masaharu Aoyama, Fujisawa, JP;
Takashi Ajima, Kamakura, JP;
Abstract
A system is adapted to etch an aluminium film on a semiconductor wafer into a predetermined pattern by immersing the film in an etching solution. The system comprises a voltage detecting circuit for detecting a voltage created between a platinum electrode and the aluminium film on the semiconductor wafer which are immersed in the etching solution, a comparator for comparing a reference voltage with the voltage detected by the voltage detecting circuit to produce an output signal, and a timer for starting a time count operation upon receipt of the output signal from the comparator and for producing an etching completion signal when it continuously receives the output signal from the comparator for a predetermined time period.