GaP的缺陷随温度变化的PAT研究

PAT INVESTIGATION OF DEFECTS CHANGE WITH THE HEAT-TREATMENT TEMPERATURES IN GaP

我们对ＬＥＣ法制成的掺Ｓ的ＧａＰ单晶，从室温至１０００℃，每隔５０℃恒温３０分钟，在Ａｒ气保护下进行热处理．用正电子湮没技术（ＰＡＴ）对样品中的缺陷进行了分析研究．结果指出，随着热处理温度的升高，ＧａＰ中的点缺陷组态发生变化．测试结果表明，正电子湮没寿命可分解为两个寿命．其中捕获态寿命τ２随热处理温度的升高，由３１０ｐｓ变为３３０ｐｓ；进而在高温下变为２８０ｐｓ．相应地捕获强度Ｉ２随温度而发生变化，它反映出ＧａＰ单晶中的空位浓度也在随温度发生变化．

LEC grown GaP S doped single crystal samples were heated-treatment from room temperature to 1000℃ with interval of 50℃ and Ar was used as safeguarding gas.The defects in GaP samples were investigated with Positron Annililation Technology(PAT) and Scanning Electron Microscopy(SEM).The experimental results indicate,point defects and dislocations exist in GaP.The composition of defects changes with heat-treatment temperature.The results of PAT investigation express that positron annililation lifetime can decompose into two parts.As the heat treatment temperature were raised, its lifetime of capture component τ2 at first increases from 310 ps into 330 ps,then decreses into 280 ps.Intensity of capture component make corresponding change with temperature raised.It reflect that concentration of defects make relevant change with the temperature.