Publication
Title
Comparison of As- and P-based metamorphic buffers for high performance InP heterojunction bipolar transistor and high electron mobility transistor applications
Author
Abstract
Metamorphic buffers (M-buffers) consisting of graded InAlAs or bulk InP were employed for the production of InP-based epiwafers on GaAs substrates by molecular-beam epitaxy. The graded InAlAs is the standard for production metamorphic high electron mobility transistors (M-HEMTs), while the bulk InP offers superior thermal properties for higher current density circuits. The surface morphology and crystal structure of the two M-buffers showed different relaxation mechanisms. The graded InAlAs gave a cross-hatched pattern with nearly full relaxation and very effective dislocation filtering, while the bulk InP had a uniform isotropic surface with dislocations propagating further up towards the active layers. Both types of M-buffers had atomic force microscopy root-mean-square roughness values around 2030 Å. The Hall transport properties of high electron mobility transistors (HEMTs) grown on the InAlAs M-buffer, and a baseline HEMT grown lattice matched on InP, both had room-temperature mobilities >10 000 cm2/V s, while the M-HEMT on the InP M-buffer showed a decrease to 9000 cm2/V  s. Similarly, the dc parameters of a double heterojunction bipolar transistor (DHBT) grown on the InAlAs M-buffer were much closer to the baseline heterojunction bipolar transistor than a DHBT grown on the InP M-buffer. A high breakdown voltage of 11.3 V was achieved on an M-DHBT with the InAlAs M-buffer. We speculate that the degradation in device characteristics on the InP M-buffer was related to the incomplete dislocation filtering.
Language
English
Source (journal)
Journal of vacuum science & technology. B. Microelectronics and nanometer structures. Processing, measurement and phenomena. - Woodbury, N.Y.
Publication
Woodbury, N.Y. : 2004
ISSN
1071-1023
Volume/pages
22:3(2004), p. 1565-1569
ISI
000222481400141
Full text (Publishers DOI)
UAntwerpen
Faculty/Department
Research group
Publication type
Subject
External links
Web of Science
Record
Identification
Creation 28.03.2011
Last edited 21.04.2017