<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Wang, Maojun</style></author><author><style face="normal" font="default" size="100%">Cheng, Chung Choi</style></author><author><style face="normal" font="default" size="100%">Beling, Chris D.</style></author><author><style face="normal" font="default" size="100%">Fung, Stevenson</style></author><author><style face="normal" font="default" size="100%">Chen, Kevin J.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Modulation of polarization field by fluorine ions in AlGaN/GaN heterostructures revealed by positron annihilation spectroscopy</style></title><secondary-title><style face="normal" font="default" size="100%">PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2010</style></year><pub-dates><date><style  face="normal" font="default" size="100%">JUN</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">6</style></number><volume><style face="normal" font="default" size="100%">207</style></volume><pages><style face="normal" font="default" size="100%">1332-1334</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Modulations of energy band and polarization field by fluorine ions in fluorine plasma treated AlGaN/GaN heterostructures were revealed by positron annihilation spectroscopy (PAS). It is found that the annihilation probability is mainly governed by the electric field in the AlGaN/GaN heterostructure, which could be modulated by charged ions, opposite to what was first expected from the large number of plasma-induced defects such as Ga-vacancies. The modulation of electric field is successfully observed through the opposite changes in the S parameters on the two sides of the hetero-interface after fluorine plasma treatment due to the opposite E-field directions. Fluorine is experimentally proved to be negatively charged in GaN related materials, which is consistent with the operation principle of enhancement-mode AlGaN/GaN HEMT fabricated by fluorine plasma treatment. It is also suggested that PAS is a useful tool to probe the intrinsic electric field in AlGaN/GaN system. (C) 2010 WILEY-VCH Verlag GmbH &amp; Co. KGaA, Weinheim</style></abstract><notes><style face="normal" font="default" size="100%">8th International Conference on Nitride Semiconductors (ICNS-8), Jeju, SOUTH KOREA, OCT 18-23, 2009</style></notes><custom7><style face="normal" font="default" size="100%">000279989000014</style></custom7></record></records></xml>