Determination of interfacial states in solid heterostructures using a variable-energy positron beam
Abstract
A method and means is provided for characterizing interfacial electron states in solid heterostructures using a variable energy positron beam to probe the solid heterostructure. The method includes the steps of directing a positron beam having a selected energy level at a point on the solid heterostructure so that the positron beam penetrates into the solid heterostructure and causes positrons to collide with the electrons at an interface of the solid heterostructure. The number and energy of gamma rays emitted from the solid heterostructure as a result of the annihilation of positrons with electrons at the interface are detected. The data is quantified as a function of the Doppler broadening of the photopeak about the 511 keV line created by the annihilation of the positrons and electrons at the interface, preferably, as an S-parameter function; and a normalized S-parameter function of the data is obtained. The function of data obtained is compared with a corresponding function of the Doppler broadening of the annihilation photopeak about 511 keV for a positron beam having a second energy level directed at the same material making up a portion of the solid heterostructure. The comparison of these functions facilitates characterization of the interfacial statesmore »
- Inventors:
- Issue Date:
- OSTI Identifier:
- 6023321
- Patent Number(s):
- 5200619
- Application Number:
- PPN: US 7-770891
- Assignee:
- Associated Universities, Inc., Washington, DC (United States)
- DOE Contract Number:
- AC02-76CH00016
- Resource Type:
- Patent
- Resource Relation:
- Patent File Date: 4 Oct 1991
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; HETEROJUNCTIONS; INTERFACES; ELECTRONIC STRUCTURE; ANNIHILATION; DOPPLER EFFECT; ELECTRONS; ENERGY LEVELS; GAMMA RADIATION; POSITRON BEAMS; SEMICONDUCTOR DEVICES; BASIC INTERACTIONS; BEAMS; ELECTROMAGNETIC INTERACTIONS; ELECTROMAGNETIC RADIATION; ELEMENTARY PARTICLES; FERMIONS; INTERACTIONS; IONIZING RADIATIONS; JUNCTIONS; LEPTON BEAMS; LEPTONS; PARTICLE BEAMS; PARTICLE INTERACTIONS; RADIATIONS; SEMICONDUCTOR JUNCTIONS; 665100* - Nuclear Techniques in Condensed Matter Physics - (1992-)
Citation Formats
Asokakumar, P P.V., and Lynn, K G. Determination of interfacial states in solid heterostructures using a variable-energy positron beam. United States: N. p., 1993.
Web.
Asokakumar, P P.V., & Lynn, K G. Determination of interfacial states in solid heterostructures using a variable-energy positron beam. United States.
Asokakumar, P P.V., and Lynn, K G. Tue .
"Determination of interfacial states in solid heterostructures using a variable-energy positron beam". United States.
@article{osti_6023321,
title = {Determination of interfacial states in solid heterostructures using a variable-energy positron beam},
author = {Asokakumar, P P.V. and Lynn, K G},
abstractNote = {A method and means is provided for characterizing interfacial electron states in solid heterostructures using a variable energy positron beam to probe the solid heterostructure. The method includes the steps of directing a positron beam having a selected energy level at a point on the solid heterostructure so that the positron beam penetrates into the solid heterostructure and causes positrons to collide with the electrons at an interface of the solid heterostructure. The number and energy of gamma rays emitted from the solid heterostructure as a result of the annihilation of positrons with electrons at the interface are detected. The data is quantified as a function of the Doppler broadening of the photopeak about the 511 keV line created by the annihilation of the positrons and electrons at the interface, preferably, as an S-parameter function; and a normalized S-parameter function of the data is obtained. The function of data obtained is compared with a corresponding function of the Doppler broadening of the annihilation photopeak about 511 keV for a positron beam having a second energy level directed at the same material making up a portion of the solid heterostructure. The comparison of these functions facilitates characterization of the interfacial states of electrons in the solid heterostructure at points corresponding to the penetration of positrons having the particular energy levels into the interface of the solid heterostructure. Accordingly, the invention provides a variable-energy non-destructive probe of solid heterostructures, such as SiO[sub 2]/Si, MOS or other semiconductor devices.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Apr 06 00:00:00 EDT 1993},
month = {Tue Apr 06 00:00:00 EDT 1993}
}