Dependence of the Decomposition of Trimethylaluminum on Oxygen Concentration
Dependence of the Decomposition of Trimethylaluminum on Oxygen Concentration
复制标题
三甲基铝的分解对氧气浓度的依赖性
DOI：
10.1149/1.3517080
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发表时间：
2011
影响因子：
3.9
通讯作者：
T. Ohmi
中科院分区：
文献类型：
--
作者：
Satoru Yamashita;K. Watanuki;H. Ishii;Yoshinobu Shiba;Masafumi Kitano;Y. Shirai;S. Sugawa;T. Ohmi
三甲基铝（TMA）经常用作含铝的复合半导体或栅极绝缘体膜的源气体。然而，TMA容易与O2反应，并且该反应导致膜性能降低。由于原料气的分解性质影响着薄膜的形成，因此研究氧气对TMA分解行为的影响具有重要意义。在充Ar气的Al2O3管中，TMA的起始分解温度为332°C，在380°C以上分解速率迅速增加然而，当TMA被加热的气氛中含有超过1 ppm的O2，温度时，TMA开始分解增加。推测这是由于TMA与O2反应生成甲氧基所致。因此，在TMA中的O2的存在不仅导致薄膜被氧原子污染，而且还改变了TMA的分解行为。这意味着当沉积条件保持恒定时，沉积速率和膜性能的波动是由TMA中的O2的存在引起的。因此，在沉积过程中，希望TMA中存在的O2浓度保持在0.1ppm以下。
Trimethylaluminum (TMA) is often used as a source gas for composite semiconductor or gate insulator films containing aluminum. However, TMA readily reacts with O 2 and this reaction causes film performance to degrade. Film formation is affected by the decomposition properties of the source gas, so it is important to investigate the influence of O 2 on the decomposition behavior of TMA. The starting decomposition temperature of TMA was 332°C in an Al 2 O 3 tube filled with Ar gas, and the decomposition rate increased rapidly above 380°C. However, when TMA was heated in an atmosphere containing more than 1 ppm O 2 , the temperature at which TMA began to decompose increased. It is assumed that this phenomenon resulted from the formation of methoxy groups through reaction between TMA and O 2 . Thus, the presence of O 2 in TMA not only caused the films to be contaminated with oxygen atoms but also altered the decomposition behavior of TMA. This means that fluctuations in the deposition rate and film performance are caused by the presence of O 2 in TMA when deposition conditions are otherwise kept constant. As a result, it is desirable that the O 2 concentration present in TMA is maintained below 0.1 ppm during deposition.