大尺寸HVPE反应器寄生沉积的数值模拟研究

发布时间：2018-05-27 00:29

  本文选题：HVPE反应器 + GaN　； 参考：《人工晶体学报》2017年04期

【摘要】：在氢化物气相外延(HVPE)生长GaN厚膜中,反应腔壁面总会产生大量的寄生沉积,严重影响薄膜生长速率及质量。本文针对自制的大尺寸垂直式HVPE反应器,通过数值模拟与实验对比,研究了反应腔壁面沉积以及GaN生长速率的分布规律,特别是寄生沉积分布与载气流量的关系。研究发现:在基准条件下,顶壁寄生沉积速率由中心向边缘逐渐降低,与实验结果吻合;侧壁沉积出现8个高寄生沉积区域,对应喷头边缘处排布的GaCl管,说明沉积主要取决于GaCl的浓度输运;模拟得出的石墨托表面生长速率低于实验速率,但趋势一致。保持其他条件不变,增大NH_3管载气N_2流量,顶壁和侧壁的寄生沉积速率及分布区域均随之增大,石墨托表面生长速率随之减小而均匀性却随之提高;增大GaCl管载气N_2流量,顶壁和侧壁的寄生沉积速率及分布区域均随之减小,石墨托表面生长速率随之增大而均匀性却随之降低。研究结果为大尺寸HVPE反应器生长GaN的工艺优化提供了理论依据。
[Abstract]:In GaN thick films grown by hydride vapor phase epitaxy (HvE), a large amount of parasitic deposition always occurs on the wall of the reaction cavity, which seriously affects the growth rate and quality of the films. In this paper, the distribution law of reaction chamber wall deposition and GaN growth rate, especially the relationship between parasitic deposition distribution and carrier gas flow rate, is studied by numerical simulation and experimental comparison for a large scale vertical HVPE reactor. It is found that the parasitic deposition rate of the parietal wall decreases gradually from the center to the edge under the reference condition, which coincides with the experimental results. There are eight high parasitic deposition areas on the lateral wall, corresponding to the GaCl tube arranged at the edge of the nozzle. The results show that the deposition mainly depends on the transport of GaCl concentration, and the simulated growth rate of graphite base surface is lower than the experimental rate, but the trend is consistent. Keeping the other conditions unchanged, the parasitic deposition rate and distribution area of the top wall and side wall increase with increasing the flow rate of NH_3 tube carrier gas, and the surface growth rate of graphite support decreases, but the uniformity increases, and the flow rate of GaCl tube carrier gas increases with the increase of the flow rate of GaCl tube carrier gas N2. The parasitic deposition rate and distribution area of the top wall and lateral wall decrease, while the growth rate of graphite base surface increases and the uniformity decreases. The results provide a theoretical basis for the process optimization of GaN growth in a large scale HVPE reactor.
【作者单位】： 江苏大学能源与动力工程学院;东莞中镓半导体科技有限公司;
【基金】：国家自然科学基金(61474058);国家自然科学基金重大仪器装备专项(61327801) 江苏省普通高校研究生科研创新计划项目(CXLX11_057) 国家高技术研究发展计划(2014AA032605) “广东特支计划”科技青年拔尖人才项目(510264251033)
【分类号】：TN304.2
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本文编号：1939620