Homogeneous growth of SiGe bulk crystals by using the traveling liquidus-zone method

我们的目的是：(1)验证旅行液区（TLZ）方法[1]不仅适用于III-V类化合物，也适用于IV-IV类化合物的均匀晶体生长；(2)利用TLZ方法生长均匀的SiGe体晶体。为了获得均匀的晶体，需要通过计算理论TLZ模型来确定最佳的样品平移速率。这意味着我们必须先知道扩散系数。因此，我们通过将一维模拟得到的数值数据与实验数据进行比较，估计了9.5×10^<-5> cm^2/s的扩散系数。利用估计的扩散系数和温度梯度，计算出样品的最佳平移速率为0.234 mm/hr。因此，利用与计算值相似的0.24 mm/hr的平移速率，我们成功地生长出了Si_<0.503>Ge_<0.497>的均匀体晶体，晶格常数的偏差很小，约为±0.025%。为了了解生长模式是TLZ模式还是其他生长模式，还进行了一维模拟。从仿真结果可以看出，生长模式应为TLZ模式，但与实验确定的偏差相比，偏差略大，为±0.05%。然而，晶格常数的偏差仍然很小，可以忽略不计。综上，我们认为TLZ方法不仅适用于III-V类化合物的晶体生长，也适用于IV-IV类化合物的晶体生长。木下等，j .晶体生长，225(2001)59。

Our aims are (1)to verify that the traveling liquidus-zone(TLZ) method [1]is applicable to the homogeneous crystal growth of not only III-V compounds but also IV-IV compounds, and (2)to grow homogeneous SiGe bulk crystals by using the TLZ method.In order to obtain homogeneous crystals, it is required to determine the optimum sample translation rate by calculating the theoretical TLZ model. This means that we must know the diffusion coefficient first. So we estimate the diffusion coefficient of 9.5×10^<-5> cm^2/s by comparing the numerical data obtained from the one-dimensional simulation with the experimental data. By using the estimated diffusion coefficient and the temperature gradient, the optimum sample translation rate of 0.234 mm/hr is calculated. Thus, by using the similar translation rate of 0.24 mm/hr to the calculated one, we succeed in growing the homogeneous bulk crystals of Si_<0.503>Ge_<0.497> with negligibly small deviation of the lattice constant, that is, about ±0.025 %.The one-dimensional simulation is also carried out in order to know whether the growth mode is the TLZ mode or other growth modes. From the simulation results, it is found that the growth mode should be the TLZ mode but the deviation is slightly large as compared with the experimentally determined deviation, ±0.05 %. However, the deviation of the lattice constant is still negligibly small. As a conclusion, we believe that the TLZ method is applicable to the crystal growth of not only III-V compounds but also IV-IV compounds.[1]K.Kinoshita et al., J.Crystal Growth,225(2001)59.