Accession Number : ADA314437

Title :   Tunable SiGe Detectors.

Descriptive Note : Final technical rept. Oct 95-Oct 96,

Corporate Author : CALSPAN UB RESEARCH CENTER BUFFALO NY

Personal Author(s) : Jimenez, Jorge R.

PDF Url : ADA314437

Report Date : AUG 1996

Pagination or Media Count : 32

Abstract : The theory of voltage tunable cut off wavelength silicide/SiGe/Si detectors is presented. Experimental data on tunable PtSi/SiGe/Si detectors is also presented. The theory is able to account for the experimentally observed behavior of tunable PtSi/SiGe/Si diodes. The tunability provided by the SiGe layer is understood as being due to two related effects: first, keeping the barrier peak position fixed with bias; and second, moving the barrier peak further away from the interface. The second effect decreases quantum efficiency, which depends on the peak to interface distance. However, maximizing the first effect allows us to obtain desired levels of tunability without potential decreases in quantum efficiency. For voltage switched, dual window imaging, a tunable range of 5-12 microns is required over moderate voltages (10-15 volts), for which calculated detector parameters are Ge percentages of at least 20%, and total SiGe thicknesses (uniform plus graded) of approx. 60-100 A and boron doping levels of approx. 4-8 x 10 to the 16th cm-3 throughout the depletion layer width (approx. 4000 A, in the SiGe and in the underlying S1).

Descriptors :   *INFRARED DETECTORS, LAYERS, SEMICONDUCTOR DIODES, SENSITIVITY, TUNING, QUANTUM EFFICIENCY, SILICON COMPOUNDS, GERMANIUM COMPOUNDS.

Subject Categories : Infrared Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE