V型坑和夹杂物的形成

1、V 型坑和夹杂物的形成Investigation of V ? Defects and embedded inclusions in InGaN/GaN multiple quantum wells grown by metalorganic chemical vapor deposition on (0001) sapphireWe have exam ined the n ature of V-defects and in elusions夹 杂物 )embedded within these defects by atomic force microscopy (AFM) and hig

2、h-resolution scanningele ct ronmicroscopy (SEM)/cathodoluminescence (CL) in InGaN/GaN multiple quantum wells (MQWs). To date, indium distribution nonuniformity in the well or QaN barrier growth temperature have been identified as the main factors responsible for the V-defec t occurrence and propagat

3、i on. Fur ther complicating the matter, inclusions embedded within V-defects originating at the firstIn GaN-to - GaN in terface have bee n observed un der cer tain growth condi tio ns. Our AFM and high-resolution SEM/CL findings provide evide nee that some V-defects occur merely as direct results of

4、 barrier temperature growth, and that there are additi onal V-defec ts associated with In-rich regi ons, which act as sinks for further indium segregation during the MQW growth.Both types of V-defects have a tendency of promoti ng in clusi onsat low-temperature (800C) GaN barrier growth in an H2-freeen vir onment. Localized st rain-en ergy variati ons associated with the apex of V-defects may be responsible for the inclusion occurre nee. Addi ng H2 duri ng the GaN barrier growth reduces V-defect formati on and suppresses in clusi on propa