预非晶化离子注入对硅p^+n结性能的影响

Influence of Preamorphized Implantation on Silicon p+n Junction Properties

用Ｓｉ＋／Ｂ＋、Ａｒ＋／Ｂ＋双注入结合快速热退火技术制备出了较浅的ｐ＋ｎ结，用四探针法、扩展电阻法、背散射沟道谱、二次离子质谱等测试分析手段研究了Ｓｉ＋或Ａｒ＋预非晶化离子注入的作用。结果表明，适当条件的Ｓｉ＋预非晶化注入能有效地抑制硼原子的沟道效应，用Ｓｉ＋／Ｂ＋双注入制备出了高硼原子电激活率的Ｐ＋薄层，且电性能优良，残留二次缺陷少，ｐ＋ｎ结二极管反偏漏电流仅２．０ｎＡ／ｃｍ２（－１．４Ｖ）；而Ａｒ＋注入虽然也能抑制硼原子注入沟道效应，但它使注入硼原子电激活率低，制得的Ｐ＋薄层性能差。

The shallow p+n junctions have been fabricated by Si+/B+Ar+/B+ dual implant,in combination with rapid thermal annealing (RTA).The effect of Si+ or Ar+ preamorphized implantation has been studied by means of FPP (four point probe),SRP(spreading resistance probe),RBS/ion channelling and SIMS(secondary ion mass spectrometer).The results show that Si+ preamorphized implantation under suitable implant conditions can effectively inhibit the boron channelling effect,which can make good electrical properties' thin p+ layer with high boron electrical active rates and little residual secondary defects;and that the p+n diodes fabricated by Si+/B+ dual implant show excellent I-V characteristics,with reverse leakage current density of 2.0nA/cm2 at -1.4V.Although the Ar+ preamorphized implantation also can inhibit the boron channelling effect,it can result in the lower boron electrical active rates,some much residual secondary defects and poor electrical properties' p+ thin layers.