Structural Characterization Of Defects In Gaas With Ultrasonic Measurements

M. J. Brophy; A. V. Granato

doi:10.1117/12.961188

26 June 1986 Structural Characterization Of Defects In Gaas With Ultrasonic Measurements

M. J. Brophy, A. V. Granato

Proceedings Volume 0623, Advanced Processing and Characterization of Semiconductors III; (1986) https://doi.org/10.1117/12.961188
Event: O-E/LASE'86 Symposium, 1986, Los Angeles, CA, United States

Abstract

Measurements of ultrasonic attenuation and velocity as a function of temperature can yield valuable structural information on defects which lower the symmetry of the lattice site on which they are located. We report here on two such defects in GaAs: the Cr impurity and the as yet inconclusively identified defects caused by low temperature irradiation with 2.25-2.5 Mev electrons. The neutral Cr impurity (Cr³⁺-[Ar]3d³) traps an electron to become Cr²⁺. This charge state undergoes a static tetragonal Jahn-Teller distortion which can be detected ultrasonically. Ultrasonic measurements at 10 frequencies between 5 and 130 MHz for differing polarizations of the stress wave confirm the tetragonal symmetry of the defect, and provide quantatative information on the kinetics of reorientation between energetically equivalent distortions. Samples with as little as .2 appm Cr were studied. Two defects with trigonal symmetry were observed to be created after the above mentioned electron irradiation. Both have reorientation kinetics obeying the Arrhenius law. The frequency factor and activation energy is 10^11.5 (10^13.2) sec and 12.5 (54.1) meV for the low (high) temperature attenuation peak. Both defects were observed to anneal out below 340 K. The low temperature peak annealed in a complicated fashion between 208 and 334K, whereas the high temperature peak exhibited single activation energy annealing above 320K. Our results suggest that no long range migration of the radiation produced defects occurs below room temperature. There is some evidence that the low temperature attenuation peak could be caused by a Ga vacancy. Several candidates for defects which could be responsible for the high temperature peak are considered and discussed.

Citation Download Citation

M. J. Brophy and A. V. Granato "Structural Characterization Of Defects In Gaas With Ultrasonic Measurements", Proc. SPIE 0623, Advanced Processing and Characterization of Semiconductors III, (26 June 1986); https://doi.org/10.1117/12.961188

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
5 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Ultrasonics

Chromium

Signal attenuation

Gallium arsenide

Electrons

Annealing

Temperature metrology

Show All Keywords

Keywords/Phrases

Search In:

Publication Years