Study of non-equilibrium thermochemical reaction between Si melt and silica glass at high temperature in Czochralski Si crystal growth

直拉硅晶体生长中高温硅熔体与石英玻璃非平衡热化学反应研究

基本信息

批准号：
13450010
负责人：
HOSHIKAWA Keigo
金额：
$ 8万
依托单位：
Faculty of Education, Shinshu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

项目摘要

In this study, the thermochemical reactions and the physical phenomena at high temperature during Czochralski (CZ) Si crystal growth have been investigated, and we noticed (a) transportation of impurity atoms in the melt and the crystal, and (b) the dislocation behavior near the interface between seed and the grown crystal. Typical results are as follows;(1) Oxygen dissolution rate from silica crucible to Si melt could be obtained precisely by sessile drop method. Ge atoms heavily doped in Si melt were evaporated with oxygen atoms dissolved from silica crucible and the evaporation rate increased with increasing Ge concentration in the melt(2) Segregation coefficient of Ge was investigated by comparing Ge concentrations in Si crystal and in corresponding Si melt, and it was about 0.48 with Ge concentration in the crystal in the range from 10^<19> to 10^<21> atoms/cm^3.(3) Dislocation due to thermal shock in heavily B-doped Si seed was investigated under different temperature conditions. The dislocation could be suppressed when B concentration in the seed was larger and temperature difference between the seed placed just above the melt surface and the melt on dipping was smaller.(4) Dislocation suppression mechanism due to lattice misfit near the interface between heavily B-doped Si seed and lightly B-doped Si grown crystal was investigated experimentally and computationally. B concentration near the interface was gradually changed and the distribution was formed by diffusion of B atoms from the heavily B-doped seed during the crystal growth.(5) Dislocations were generated in the grown crystal although the dislocations due to both thermal shock and lattice misfit were suppressed by using a heavily B and Ge codoped Si seed. Such dislocation was generated in the case of lower melt temperature, and we conclude that the dislocation was due to incomplete seeding.

在这项研究中，研究了直拉（CZ）硅晶体生长过程中的热化学反应和高温物理现象，我们注意到（a）熔体和晶体中杂质原子的传输，以及（b）位错行为靠近种子和生长晶体之间的界面。典型结果如下： (1)采用座滴法可以精确获得石英坩埚到硅熔体的氧溶解速率。 Si 熔体中重掺杂的 Ge 原子与石英坩埚中溶解的氧原子一起蒸发，蒸发速率随着熔体中 Ge 浓度的增加而增加（2）通过比较 Si 晶体和相应 Si 熔体中的 Ge 浓度，研究了 Ge 的偏析系数，晶体中 Ge 浓度在 10^<19> 至 10^<21> 原子/cm^3 范围内时，其约为 0.48。 (3) 在以下条件下研究了重 B 掺杂 Si 籽晶中热冲击引起的位错。不同的温度条件。当籽晶中B浓度较大且置于熔体表面上方的籽晶与浸渍时熔体之间的温差较小时，位错可以被抑制。(4)由于重B-之间界面附近的晶格失配而产生的位错抑制机制。通过实验和计算研究了掺杂硅晶种和轻硼掺杂硅生长晶体。在晶体生长过程中，界面附近的B浓度逐渐变化，并且分布是由于B原子从重B掺杂种子中扩散而形成的。(5)虽然热冲击和晶格造成的位错，但在生长的晶体中产生了位错。通过使用重度 B 和 Ge 共掺杂的 Si 种子来抑制失配。这种位错是在较低熔化温度的情况下产生的，我们得出结论，位错是由于晶种不完全造成的。