Spatially resolved localized vibrational mode spectroscopy of carbon in liquid encapsulated Czochralski grown gallium arsenide wafers

Technical Report · Fri Apr 01 04:00:00 EST 1988

DOI:https://doi.org/10.2172/5398032· OSTI ID:5398032

Yau, Waifan

Substitutional carbon on an arsenic lattice site is the shallowest and one of the most dominant acceptors in semi-insulating Liquid Encapsulated Czochralski (LEC) GaAs. However, the role of this acceptor in determining the well known W'' shape spatial variation of neutral EL2 concentration along the diameter of a LEC wafer is not known. In this thesis, we attempt to clarify the issue of the carbon acceptor's effect on this W'' shaped variation by measuring spatial profiles of this acceptor along the radius of three different as-grown LEC GaAs wafers. With localized vibrational mode absorption spectroscopy, we find that the profile of the carbon acceptor is relatively constant along the radius of each wafer. Average values of concentration are 8 {times} 10E15 cm{sup -3}, 1.1 {times} 10E15 cm{sup -3}, and 2.2 {times} 10E15 cm{sup -3}, respectively. In addition, these carbon acceptor LVM measurements indicate that a residual donor with concentration comparable to carbon exists in these wafers and it is a good candidate for the observed neutral EL2 concentration variation. 22 refs., 39 figs.

• Research Organization: Lawrence Berkeley Lab., CA (USA)
• Sponsoring Organization: DOE/ER
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5398032
• Report Number(s): LBL-25790; ON: DE90003121
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201 -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
656002* -- Condensed Matter Physics-- General Techniques in Condensed Matter-- (1987-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION SPECTROSCOPY
ALLOYS
ARSENIC COMPOUNDS
ARSENIDES
BAND THEORY
CARBON ADDITIONS
CHARGE STATE
CONTROL EQUIPMENT
CRYOSTATS
ENERGY LEVELS
EQUIPMENT
EXCITED STATES
FERMI LEVEL
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
INTERFEROMETERS
MATERIALS
MEASURING INSTRUMENTS
PHOTOCONDUCTORS
PNICTIDES
SEMICONDUCTOR MATERIALS
SPECTROMETERS
SPECTROSCOPY
THERMOSTATS
VIBRATIONAL STATES