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. 09, 1981
Filed:
Jun. 04, 1979
James B Compton, Los Gatos, CA (US);
Robert A Cometta, San Jose, CA (US);
Daniel D Culmer, Sunnyvale, CA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
An element of an integrated circuit, such as an ion implanted region or a metal layer, may be laser trimmed without exposing P-N junctions or other circuit elements not to be trimmed to damage by the laser through use of the present protection process and structure. In the process, an oxide through which the laser trimming is carried out is formed over a selected portion of the circuit to be trimmed by the laser. A bare layer of a metal reflective to the laser radiant energy beam, such as aluminum, gold or silver, is formed surrounding the selected portion of the circuit. The selected portion of the integrated circuit is then trimmed with the laser. The oxide promotes trimming in the selected area by absorbing the laser radiant energy beam. The bare metal layer protects the portion of the integrated circuit underlying it by reflecting most of its energy.