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. 08, 1992
Filed:
Oct. 11, 1991
Erdmann F Schubert, New Providence, NJ (US);
Li-Wei Tu, Westfield, NJ (US);
George J Zydzik, Columbia, NJ (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
Conduction band or valence band discontinuities occurring at the junction of two unipolar heterogeneous semiconductors can be eliminated by compositional grading of the heterointerface and appropriate doping of the interfacial region. The compositional potential of graded junction and an interface dipole potential generated by modulation doping of the interfacial region are selected such that they exactly compensate each other. The compositional grading of the interface is achieved by semiparabolic grading of narrow regions immediately adjacent each side of the interface. The modulation doping is achieved by doping the two materials with suitable dopants, donors for the conductance band or acceptors for the valence band, depending on the polarity of the structure. This reduces the resistance in periodic semiconductor multilayer structures leading to low-resistance distributed Bragg reflectors.