快速热处理对电子辐照直拉硅中氧沉淀的影响

对n型111]晶向直拉硅样品进行电子辐照,然后分别在不同温度和降温速率下快速热处理(rapid thermal process,RTP),再在1100℃下进行常规一步退火。研究了RTP温度和降温速率对硅样品内氧沉淀的变化及样品表面清洁区形成的影响。结果表明:经过RTP再经高温一步退火后,硅晶体内形成了密度较高的氧化诱生层错以及完整的位错环,样品表面形成了一定宽度的清洁区;清洁区的宽度随RTP温度及降温速率的升高而变窄。当RTP温度达到1280℃时,样品中的层错和位错环明显减少,此时当RTP降温速率增加至150℃/s时,大部分层错消失,样品中出现了大量的点状腐蚀坑。

EFFECT OF RAPID THERMAL PROCESS ON OXYGEN PRECIPITATION IN ELECTRON IRRADIATED CZOCHRALSKI SILICON

The n-type 111] silicon single crystal sample grown by Czochralski method was irradiated via an electron beam. The rapid thermal process (RTP) treatments of the silicon crystal at different temperatures and cooling rates and annealing at 1 100 ℃ were then carried out. The effects of RTP on the oxygen precipitation and the denuded zone (DZ) formation in electron irradiated silicon samples were investigated. The results show that oxidation induced stacking faults and the complete dislocation loops are formed in the silicon sample after RTP and pre-annealing. The DZ is also formed on the silicon sample surface. Furthermore, the width of DZ become narrow with the increasing of the RTP temperature and the cooling rate. The stacking faults and dislocation loops in samples decrease when the RTP temperature reaches 1 280 ℃. When the RTP cooling rate increases to 150 ℃/s, most of stacking faults disappear and a large number of point-like corrosion pits appear in the sample.