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Deep levels associated with dislocation annihilation by Al pre-seeding and silicon delta doping in GaN grown on Si(111) substrates

✍ Scribed by Soh, C. B. ;Zang, K. Y. ;Wang, L. S. ;Chow, S. Y. ;Chua, S. J.


Book ID
105364541
Publisher
John Wiley and Sons
Year
2008
Tongue
English
Weight
247 KB
Volume
205
Category
Article
ISSN
0031-8965

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✦ Synopsis


Abstract

The introduction of Si burst during the growth of GaN film on Si(111) substrate by MOCVD formed a Si__~x~__ N__~y~__ layer which leads to an effective reduction in the density of screw dislocations. The reduction is associated with bending of screw dislocations to form a square dislocation loop when neighbouring dislocations with opposite Burger's vector paired up. The concentration of electron traps E~c~–E~t~ ∼0.17–0.26 eV which is associated with screw dislocations is substantially reduced and a kink is left at the silicon rich position. The mixed‐edge dislocation, however, is not annihilated by the Si__~x~__ N__~y~__ layer. Addition of TMAl burst for the AlN growth leads to a substantial reduction in trap concentration associated with the nitrogen vacancies, V~N~, and antisite of nitrogen, N~Al~, at E~c~–E~t~ ∼0.10 eV and E~c~–E~t~ ∼ 0.60 eV respectively. This improves the quality of the subsequent layer of HT‐GaN grown and is useful for device fabrication. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)