Influence and Suppression of Harmful Effects Due to By-Product in CVD Reactor for 4H-SiC Epitaxy
Influence and Suppression of Harmful Effects Due to By-Product in CVD Reactor for 4H-SiC Epitaxy
复制标题
4H-SiC外延CVD反应器副产物有害影响的影响及抑制
DOI：
10.1109/tsm.2021.3077627
复制
发表时间：
2021
影响因子：
2.7
通讯作者：
Yoshikazu Moriyama
中科院分区：
文献类型：
--
作者：
Y. Daigo;Toru Watanabe;A. Ishiguro;S. Ishii;Yoshikazu Moriyama
研究了抑制副产物对高速旋转垂直CVD法同质外延生长4 H-SiC薄膜的不利影响。在两个对比研究中，研究了外延生长过程中形成的副产物，例如热壁上的3C-SiC存款和气体喷嘴上的Si存款的影响。通过对薄膜上3C-SiC降膜三角形缺陷的分析，发现大部分降膜是在外延生长前从热壁剥离下来的，并附着在硅片上。通过在晶片刚装入反应器之后将晶片转速增加到300 rpm，有效地消除了向晶片表面落下的下落，并且与保持晶片转速为50 rpm直到外延生长步骤之前的情况相比，反应器的维护时间可以增加4倍以上。此外，在气体入口处的气体喷嘴上形成的Si存款与膜的厚度和掺杂浓度的波动之间的关系表明，在气体喷嘴上形成的Si存款充当Si源气体的捕获位点。通过使用优化的气体流动条件抑制Si存款，没有观察到膜的厚度和掺杂浓度的显著波动，并且与使用其上形成Si存款的喷嘴的外延生长相比，气体喷嘴的维护周期可以增加3倍以上。
Suppression of harmful effect due to by-product on homo-epitaxial growth of 4H-SiC films using a high speed wafer rotation vertical CVD method was demonstrated. Influence of by-product, such as 3C-SiC deposit on a hot-wall and Si deposit on gas nozzles, formed during the epitaxial growth was investigated in two comparative studies. The analysis of triangular defects with 3C-SiC down-falls on the films revealed that the most of the down-falls which were peeled from the hot-wall adhered to the wafers before the epitaxial growth. By increasing the wafer rotation speed to 300 rpm just after wafer loading into the reactor, the down-falls dropped towards the wafer surface were effectively eliminated, and the maintenance period of the reactor could be increased more than 4 times compared to the case of maintaining the wafer rotation speed of 50 rpm until just before epitaxial growth step. Additionally, the relationship between Si deposit formed on the gas nozzles in the gas inlet and fluctuation of thickness and doping concentration of the films suggested that Si deposit formed on the gas nozzles acts as a trap site of Si source gas. By suppression of the Si deposit using optimizing gas flow condition, no significant fluctuation of thickness and doping concentration of the films were observed and the maintenance period of the gas nozzles could be increased more than 3 times compared to the epitaxial growth using the nozzles on which Si deposit was formed.