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Title: Apparatus for measuring minority carrier lifetimes in semiconductor materials

Abstract

An apparatus for determining the minority carrier lifetime of a semiconductor sample includes a positioner for moving the sample relative to a coil. The coil is connected to a bridge circuit such that the impedance of one arm of the bridge circuit is varied as sample is positioned relative to the coil. The sample is positioned relative to the coil such that any change in the photoconductance of the sample created by illumination of the sample creates a linearly related change in the input impedance of the bridge circuit. In addition, the apparatus is calibrated to work at a fixed frequency so that the apparatus maintains a consistently high sensitivity and high linearly for samples of different sizes, shapes, and material properties. When a light source illuminates the sample, the impedance of the bridge circuit is altered as excess carriers are generated in the sample, thereby producing a measurable signal indicative of the minority carrier lifetimes or recombination rates of the sample.

Inventors:
 [1]
  1. Lakewood, CO
Issue Date:
Research Org.:
Midwest Research Institute, Kansas City, MO (United States)
OSTI Identifier:
872413
Patent Number(s):
5929652
Assignee:
Midwest Research Institute (Kansas City, MO)
Patent Classifications (CPCs):
G - PHYSICS G01 - MEASURING G01R - MEASURING ELECTRIC VARIABLES
H - ELECTRICITY H01 - BASIC ELECTRIC ELEMENTS H01L - SEMICONDUCTOR DEVICES
DOE Contract Number:  
AC36-83CH10093
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
apparatus; measuring; minority; carrier; lifetimes; semiconductor; materials; determining; lifetime; sample; positioner; moving; relative; coil; connected; bridge; circuit; impedance; arm; varied; positioned; change; photoconductance; created; illumination; creates; linearly; related; input; addition; calibrated; fixed; frequency; maintains; consistently; sensitivity; samples; sizes; shapes; material; properties; light; source; illuminates; altered; excess; carriers; generated; producing; measurable; signal; indicative; recombination; rates; semiconductor materials; light source; semiconductor material; material properties; minority carrier; bridge circuit; signal indicative; positioned relative; carrier lifetime; semiconductor sample; sample relative; source illuminates; fixed frequency; input impedance; carrier lifetimes; linearly related; measuring minority; recombination rate; /324/

Citation Formats

Ahrenkiel, Richard K. Apparatus for measuring minority carrier lifetimes in semiconductor materials. United States: N. p., 1999. Web.
Ahrenkiel, Richard K. Apparatus for measuring minority carrier lifetimes in semiconductor materials. United States.
Ahrenkiel, Richard K. Fri . "Apparatus for measuring minority carrier lifetimes in semiconductor materials". United States. https://www.osti.gov/servlets/purl/872413.
@article{osti_872413,
title = {Apparatus for measuring minority carrier lifetimes in semiconductor materials},
author = {Ahrenkiel, Richard K},
abstractNote = {An apparatus for determining the minority carrier lifetime of a semiconductor sample includes a positioner for moving the sample relative to a coil. The coil is connected to a bridge circuit such that the impedance of one arm of the bridge circuit is varied as sample is positioned relative to the coil. The sample is positioned relative to the coil such that any change in the photoconductance of the sample created by illumination of the sample creates a linearly related change in the input impedance of the bridge circuit. In addition, the apparatus is calibrated to work at a fixed frequency so that the apparatus maintains a consistently high sensitivity and high linearly for samples of different sizes, shapes, and material properties. When a light source illuminates the sample, the impedance of the bridge circuit is altered as excess carriers are generated in the sample, thereby producing a measurable signal indicative of the minority carrier lifetimes or recombination rates of the sample.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1999},
month = {1}
}

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Works referenced in this record:

Contactless measurement of bulk carrier lifetime in thick silicon wafers by an induced eddy current
journal, January 1995


Ultra-high frequency photoconductive decay for measuring recombination lifetime in silicon
conference, January 1996


Determination of surface recombination velocity and bulk lifetime in detector grade silicon and germanium crystals
journal, January 1994


Contactless Measurement of Carrier Lifetime in Silicon Thick Wafers
journal, December 1993