摘要
文章研究了A lGaN材料的MOCVD生长机制。在位监控曲线表明,A lGaN材料生长过程是由三维生长逐渐过渡到二维生长,由于A l原子表面迁移率太小,随着TMA l流量的增加,需要更长的时间才能出现二维生长,材料质量也随着A l组分的增加而下降,A lGaN的表面形貌也变差。随着TMA l流量的增加,A lGaN材料的生长速率反而下降,这是由于A l原子阻止了Ga原子参与材料生长。实验还发现,由于TMA l与NH3之间存在强烈的寄生反应,A lGaN材料中的A l组分远小于气相中的A l组分。文中简单探讨了提高A lGaN材料质量的生长方法。
The growth of AIGaN films on sapphire substrate by metalorganic chemical vapor deposition are investigated. Through studying the traces of in situ optical reflectivity,we have observed that the quasi two-dimensional growth of AlGaN occurred followed by three-dimensional growth in the initial stage. Due to low surface mobility of Al atoms, it will take more time to transfer the two-dimensional growth into three-dimentional growth in the process. Since there are parasitic reaction of TMAl and NH3, the Al content in solid phase is much less than that in vapor phase. We have also found that the growth rate of AlGaN decrease with increasing the flux of TMAl, this may be attribute to the siteblocking effect in which the competitive adsorption of TMAl decreases the TMGa reaction with NH3 on the surface. The possible method of improving the AlGaN quality is discussed.
出处
《激光与红外》
CAS
CSCD
北大核心
2005年第11期873-876,共4页
Laser & Infrared
作者简介
赵德刚（1972-）,男,副研究员,博士,目前主要从事GaN材料生长与器件研究.
