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. 09, 1993
Filed:
Sep. 17, 1991
Pierre M Petroff, Santa Barbara, CA (US);
University of California Office of Technology Transfer, Alameda, CA (US);
Abstract
A method for modulation doping of semiconductor heterostructures includes forming a semiconductor heterostructure comprising a substrate layer, a narrow band-gap quantum well layer, and a donor implantation layer. A focused ion beam writes across the surface of the donor implantation layer, at a maximum angle of incident less than that of the channeling half-angle .alpha. of the donor implantation layer. Channeled dopant ions penetrate deep within the donor implantation layer, far from surface damage sites, and away from the quantum well layer. The addition of a dechanneling layer within the donor implantation layer, and of a series of spacer layers, further localizes the implanted donor ions and separates these ions from the quantum well layer. Once activated by a thermal annealing process, the donor ions release carriers into the quantum well layer where carrier mobility is unimpeded by donor ion collisions. An alternative embodiment implants the donor ions before the heterostructure is completely formed. Another alternative embodiment deposits concentrations of dopant ions partially into the quantum layer, where the ions serve as point defects causing interdiffusion of the donor implantation layer material and that of the quantum well layer. Quantum well regions are formed, separated by interdiffusion regions containing donor ions.