Growth of Semiconductor Bulk Single Crystals

几乎所有的电子和光电子器件都需要单晶结构的半导体材料。这些材料被称为单晶，并且通过称为晶体生长的固化过程产生。今天，大多数大块半导体单晶是通过称为熔体/溶液技术的生长工艺从液相生长的。这些增长技术是从手工艺发展而来的，非常依赖经验和直觉。即使在今天，这是大多数技术的情况下，如果不是在所有。两次生产相同的晶体仍然是一个挑战。因此，本申请人的研究工作集中在使这些晶体生长技术科学化，从而可以可重复地生长所需的高质量晶体。这是拟议研究计划的主要目标。 在实现这一主要目标的方向上，拟议的研究计划将集中在：i）SixGe 1-x的生长通过液相扩散（LPD）技术从锗侧获得具有更高硅成分的（硅锗）单晶（浓度）高达40%，ii）CdxZn 1-xTe的生长（CZT;碲锌镉）单晶具有均匀的锌（Zn）组成，和iii）在各种温度水平下将硅（Si）溶解到锗（Ge）熔体中。将通过研究在这些过程中发生的液相（熔体）中的流体流动、传热和传质以及固相（生长的晶体、进料）中的传热和传质来确定用于均匀晶体组成、稳定生长/溶解界面以及液体溶液/熔体中最有利的混合和杂质（掺杂剂）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.