Defect studies in HVPE GaN by positron annihilation spectroscopy

Filip Tuomisto

doi:10.1117/12.697892

8 February 2007 Defect studies in HVPE GaN by positron annihilation spectroscopy

Filip Tuomisto

Proceedings Volume 6473, Gallium Nitride Materials and Devices II; 647312 (2007) https://doi.org/10.1117/12.697892
Event: Integrated Optoelectronic Devices 2007, 2007, San Jose, California, United States

Abstract

We have used positron annihilation spectroscopy to study GaN grown by hydride vapor epitaxy. Our results imply that Ga vacancies in GaN are the dominant intrinsic acceptor defects in n-type nominally undoped pure material. Our experiments also show the universal role of the Ga vacancy as the most important compensating acceptor over four orders of magnitude of intentional oxygen doping. We have been able to identify the in-grown Ga vacancy-related defects as V_Ga-O_N pairs and to determine both the binding energy of the pair as well as the formation energy of the isolated Ga vacancy. The experiments performed in polar homo-epitaxial GaN and non-polar hetero-epitaxial GaN give support for a growth-surface-dependent defect incorporation model. On the other hand, the incorporation of impurities in hetero-epitaxial Ga-polar GaN seems to be dominated by effects related to extended defects such as dislocations. The preliminary results obtained in electron irradiated GaN show that negatively charged isolated Ga vacancies are produced together with non-open volume negative ion-type defects when 2-MeV electrons are used, while neutral N vacancy related defects seem to trap positrons in the material irradiated with 0.45 MeV electrons.

Citation Download Citation

Filip Tuomisto "Defect studies in HVPE GaN by positron annihilation spectroscopy", Proc. SPIE 6473, Gallium Nitride Materials and Devices II, 647312 (8 February 2007); https://doi.org/10.1117/12.697892

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