Strain control of AlGaN/GaN high electron mobility transistor structures on silicon (111) by plasma assisted molecular beam epitaxy
Strain control of AlGaN/GaN high electron mobility transistor structures on silicon (111) by plasma assisted molecular beam epitaxy
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DOI：
10.1063/1.4729045
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发表时间：
2012-06
影响因子：
3.2
通讯作者：
R. Aidam;E. Diwo;N. Rollbühler;L. Kirste;F. Benkhelifa
中科院分区：
文献类型：
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作者：
R. Aidam;E. Diwo;N. Rollbühler;L. Kirste;F. Benkhelifa
本文报道了用等离子体辅助分子束外延技术在4In衬底上生长的AlGaN/GaN基高电子迁移率晶体管结构。Si(111)衬底。在生长过程中对晶片曲率的原位测量被证明是分析缓冲层厚度依赖应变的一种非常有效的方法。GaN缓冲层生长初期的Ga/N比是控制整个生长结构压缩应变的关键参数。必须在结构中设计工程量的压缩应变，以完美地补偿样品在从生长温度冷却过程中，由于表面层和衬底之间的热膨胀系数的差异而产生的拉伸应变。薄膜的最大厚度为4.2μm，在10μm以下没有形成任何裂纹和可忽略的弓形。对生长的硅片的测量表明，载流子浓度的深度分布与在碳化硅衬底上获得的值相当。
This paper reports on the use of plasma assisted molecular beam epitaxy of AlGaN/GaN-based high electron mobility transistor structures grown on 4 in. Si (111) substrates. In situ measurements of wafer curvature during growth proved to be a very powerful method to analyze the buffer layer’s thickness dependent strain. The Ga/N ratio at the beginning of growth of the GaN buffer layer is the critical parameter to control the compressive strain of the entire grown structure. An engineered amount of compressive strain must be designed into the structure to perfectly compensate for the tensile strain caused by differences in the thermal expansion coefficient between the epi-layer and substrate during sample cool down from growth temperatures. A maximum film thickness of 4.2 μm was achieved without the formation of any cracks and a negligible bow of the wafers below 10 μm. Measurement of the as-grown wafers revealed depth profiles of the charge carrier concentration comparable to values achieved on SiC substrat...