Effect of metallisation on surface acoustic wave velocity in GaN-on-sapphire structures

Author

Ciplys, D. ; Rimeika, R. ; Gaska, R. ; Shur, Michael S. ; Khan, Ajmal ; Yang, J.W.

Author_Institution

Fac. of Phys., Vilnius Univ.

Volume

36

Issue

6

fYear

2000

fDate

3/16/2000 12:00:00 AM

Firstpage

591

Lastpage

592

Abstract

Surface acoustic wave (SAW) velocities have been measured on the free and metallised surfaces of GaN layers grown by metal organic chemical vapour deposition on (0001) sapphire substrates. The measurements were performed using the acousto-optic diffraction technique in the frequency range 100-400 MHz for SAW propagation direction along the [112¯0] sapphire axis. the deposition of thin aluminium films on the GaN surface reduced the SAW velocity up to 1% as compared to that on the free surface of the GaN-on-sapphire structure. The level of reduction was found to increase linearly with the acoustic frequency and GaN layer thickness

Keywords

aluminium; gallium compounds; metallisation; sapphire; surface acoustic wave devices; ultrasonic velocity; (0001) sapphire substrates; 100 to 400 MHz; Al-GaN-Al₂O₃; Al₂O₃; GaN layer thickness; GaN-on-sapphire structures; MOCVD deposition; SAW velocities; acoustic frequency; acousto-optic diffraction technique; metallisation effect; surface acoustic wave velocity; thin Al films;

fLanguage

English

Journal_Title

Electronics Letters

Publisher

iet

ISSN

0013-5194

Type

jour

DOI

10.1049/el:20000415

Filename

840188