Growth of Semiconductor Bulk Single Crystals

几乎所有的电子和光电设备都需要单晶结构的半导体材料。这些材料被称为单晶，由一种称为晶体生长的凝固过程产生。今天，大多数块体半导体单晶是通过称为熔融/溶液技术的生长过程从液态生长出来的。这些生长技术是从手工演变而来的，非常依赖经验和直觉。即使在今天，大多数技术都是如此，如果不是全部的话。两次生产相同的晶体仍然是一个挑战。因此，申请人的研究努力集中在使这些晶体生长技术科学化，以便能够重复生长所需的高质量晶体。这是拟议的研究计划的主要目标。 为了实现这一主要目标，拟议的研究计划将集中在：i)通过液相扩散(LPD)技术从锗一侧生长硅成分(浓度)高达40%的SixGe1-x(硅锗)单晶，ii)使用锥形新型坩埚的移动加热法(THM)生长锌(锌)组分均匀的CdxZn1-xTe(CZT；碲化锌镉)单晶，以及iii)在不同的温度水平下将硅(Si)溶解到锗(Ge)熔体中。通过研究在这些过程中发生的流体流动、液相(熔体)中的热质传递和固相(生长晶体、进料)中的热质传递，可以确定均匀的晶体组成、稳定的生长/溶解界面以及最有利的混合和杂质(杂质)在液体/熔体中传输的最佳生长条件。

Almost all electronic and optoelectronic devices need semiconducting materials of single crystalline structure. These materials are called single crystals, and are produced by a solidification process called crystal growth. Today, most bulk semiconductor single crystals are grown from the liquid phase by the growth processes known as the melt/solution techniques. These growth techniques have evolved from artisanship, relying very much on experience and intuition. Even today, this is the case in most techniques if not in all. The production of the same crystal twice is still a challenge. The applicant's research efforts have thus been focused on making these crystal growth techniques scientific so that the desired high quality crystals can be grown reproducibly. This is the main objective of the proposed research program. In the direction of achieving this main objective, the proposed research program will focus on: i) Growth of SixGe1-x (silicon germanium) single crystals from the germanium side by the Liquid Phase Diffusion (LPD) technique with higher silicon compositions (concentrations) up to 40%, ii) Growth of CdxZn1-xTe (CZT; cadmium zinc telluride) single crystals with uniform zinc (Zn) compositions by the Travelling Heater Method (THM) using tapered novel crucibles, and iii) Dissolution of silicon (Si) into germanium (Ge) melt at various temperature levels. Optimum growth conditions for uniform crystal composition, stable growth/dissolution interfaces, and most favorable mixing and impurity (dopant) transport in the liquid solution/melt will be determined by studying fluid flow, heat and mass transfer in the liquid phase (melt) and heat and mass transfer in the solid phases (grown crystal, feed)) occurring during these processes.