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本文叙述了如何用切克劳斯基法来制备P型掺金锗单晶。根据卅多次拉晶实验,我们总结得到制备时的要求:①金的加料要适当偏高,②锗料要过熔。给出了掺入金浓度沿锭长的分布,金浓度由首端至尾端逐渐升高。制备过程中观察到了一些异常现象。如①颗粒状悬浮物的析出。②单晶尾部有金的富集。③单晶表面有“沟渠”。对这些现象我们进行了讨论。在77°K—400°K范围内测量了P型掺金锗的电阻率及霍尔系数。所得曲线与敦莱普的实验作了比较。定性地解释了这些曲线,并根据霍尔系数确定了各样品的金原子浓度。由陷阱比γ=2的曲线算出了金的电离能为0.15电子伏特。用光磁法及补偿法测量了样品的寿命。实验是在77°K—400°K范围内进行。按多荷电中心复合理论对实验结果作了讨论,认为我们所测寿命确实是由金原子复合作用所决定,并受到表面复合的影响。由掺金浓度为2×10~(-14)cm~(-3)的样品之寿命值,估计出一次负电中心对电子的俘获截面是~8×10~(-17)cm~2。
This article describes how to use Czochralski method to prepare P-doped germanium single crystal. According to 卅 multiple crystal pulling experiments, we concluded that when the preparation requirements: ① gold feeding should be appropriate high, ② germanium material to be too melting. The distribution of doping concentration along the ingot length is given, and the gold concentration gradually increases from the beginning to the end. Some anomalies were observed during the preparation. Such as ① granular suspended solids precipitation. ② monocrystalline tail gold enrichment. ③ single crystal surface “ditches.” We have discussed these phenomena. The resistivity and Hall coefficient of P-doped germanium were measured in the range of 77 ° K-400 ° K. The resulting curve is compared with Dun Laipu’s experiment. These curves are qualitatively explained and the gold concentration of each sample is determined from the Hall coefficient. The curve of the trap ratio γ = 2 shows that the ionization energy of gold is 0.15 eV. The life of the sample was measured by magneto-optical method and compensation method. Experiments were conducted in the 77 ° K-400 ° K range. According to the theory of multi-charge center compound theory, the experimental results are discussed. It is believed that the lifetime measured by us is indeed determined by the complexation of gold atoms and is affected by the surface recombination. From the lifetime of the sample doped with gold at the concentration of 2 × 10 ~ (-14) cm ~ (-3), it is estimated that the electron trapping cross section at the negative charge center is ~ 8 × 10 ~ (-17) cm ~ 2.