半导体中浅杂质的傅里叶变换光热电离光谱

FOURIER TRANSFORM PHOTOTHERMAL IONIZATION SPEC-TROSCOPY OF SHALLOW IMPURITIES IN SEMICONDUCTORS

本文报道与快扫描傅里叶变换红外光谱仪相结合的光热电离光谱实验装置和测量系统。采用该系统高分辨率、高灵敏度地研究和测量高纯锗和高纯硅中的剩余浅杂质获得成功。在P型超纯Ge中发现浓度低达10~8cm^(-3)的硼受主杂质的光热电离谱线,而探测灵敏度则至少可达10~7cm^(-3);在n型高纯Si中观测到Li-O复合型浅施主中心D(Li,O);施加本征激发光后在P型高纯Si中同时观察到B受主和P施主的跃迁谱线系。此外,在Si,Ge中均观察到与浅杂质更高激发态有关的跃迁。

We report the experimental set-up and measurement system combining with a fast-scan Fourier transform spectrometer for photothermal ionization spectroscopy. They have been successfully applied for the investigation and detection of residual shallow impurity centers in ultra-pure germanium and silicon single crystals with high resolution as well as high sensitivity. Boron acceptor at a concentration of the order of magnitude of 10~8 cm^(-3) has been detected in ultra-pure germanium, and the detection limit of at least 10~7 cm^(-3) has been demonstrated. Lithiumoxygen donor complex D(Li, O) has been revealed in n-type highpurity silicon. Transition line series of both boron acceptor and phosphorus donor in p-type high-purity silicon have been observed simultaneously with the excitation of intrinsic light. In addition, the transitions associated with higher excited states of shallow impurities in both germanium and silicon have also been observed.