March 2008

Journal

Doping Characterization of InAs/GaAs Quantum Dot Heterostructure by Cross-Sectional Scanning Capacitance Microscopy

By:
Zhao, Z.; Zhang, W,; Yi, C.; Stiff-Roberts, A.; Rodriguez, Brian J; Baddorf, Arthur P
Journal Name:
Applied Physics Letters
Page Number:
92101
Volume:
92
Issue Number:
9
Publication Date:
March 2008
View DOI Listing:
https://doi.org/10.1063/1.2889938

Abstract

In order to better understand dopant incorporation in quantum dot infrared photodetectors, the novel application of cross-sectional scanning capacitance microscopy (SCM) has been used to investigate carrier occupation/distribution in a multi-layer InAs/GaAs quantum dot (QD) heterostructure for different doping techniques. The doping schemes in the QD structure include direct-doping (in InAs QD layers) and remote-doping (in GaAs barrier layers), each with different doping concentrations. The SCM image suggests electrons in direct-doping layers are redistributed due to large band-bending induced by highly-doped, remote-doping layers. The experimental result is supported by a bandstructure calculation using the Schr�dinger-Poisson method by Nextnano.