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. 12, 2002
Filed:
Jul. 20, 2000
Stepan Essaian, San Jose, CA (US);
Abdalla A. Naem, Overijse, BE;
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
Extremely high dopant concentrations are uniformly introduced into a semiconductor material by laser annealing aided by an anti-reflective coating (ARC). A spin-on-glass (SOG) film containing dopant is formed on top of the semiconductor material. An ARC is then formed over the doped SOG layer. Application of radiation from an excimer laser to the ARC heats and melts the doped SOG film and the underlying semiconductor material. During this melting process, dopant from the SOG film diffuses uniformly within the semiconductor material. Upon removal of the laser radiation, the semiconductor material cools and crystallizes, evenly incorporating the diffused dopant within its lattice structure. The ARC suppresses reflection of the laser by the doped material, promoting efficient transfer of energy from the laser to heat and melt the underlying doped layer and semiconductor material. The present process is especially suited for introducing extremely high levels of conductivity-altering dopant (10 atoms/cm ) into the polysilicon emitter of a heterojunction bipolar transistor device.