Patent ID: 6787882
Filing Date: 2004-09-07
Classification: H01L

Abstract:
A varactor diode comprising:a substrate of semiconducting material; a plurality of barrier layers and a plurality of quantum-well layers alternately interleaved with each other and disposed on said substrate so as to form a multiple quantum-well heterostructure; a depletion region formed in said multiple quantum-well heterostructure, wherein said depletion region comprises a predetermined number of said plurality of barrier layers and a predetermined number of said plurality of quantum-well layers, wherein each of said predetermined number of barrier layers is doped with an n-type impurity concentration of 1Ã—1016 cmâˆ’3, and wherein each of said predetermined number of quantum-well layers is doped with an n-type impurity concentration of at least 1Ã—1018 cmâˆ’3; an embedded region formed in said multiple quantum-well heterostructure so as to be electrically connected to each of said barrier layers and each of said quantum-well layers; and a substrate contact electrically connected to said embedded region and a region contact electrically connected to said depletion region for enabling an external voltage to be applied between said substrate contact and said region contact so as to cause a variation in said depletion region as a result of a variation in the external voltage.