Diffuse optical reflectivity measurements on GaAs during molecular‐beam epitaxy processing
Diffuse optical reflectivity measurements on GaAs during molecular‐beam epitaxy processing
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DOI：
10.1116/1.577880
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发表时间：
1992-07
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影响因子：
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通讯作者：
C. Lavoie;S. Johnson;J. Mackenzie;T. Tiedje;T. Buuren
中科院分区：
文献类型：
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作者：
C. Lavoie;S. Johnson;J. Mackenzie;T. Tiedje;T. Buuren
分子束外延中 GaAs 衬底的漫反射和镜面反射率的原位测量表明，GaAs 表面在氧化物热解吸过程中变粗糙，在缓冲层生长过程中变平滑。当氧化物解吸时，漫反射率在小于 0.4 °C 的温度区间内突然增加。这提供了方便的光学特征，用于确定基材何时清洁。氧化物解吸温度和表面粗糙化量都随着氧化物厚度的增加而增加。缓冲层生长期间漫反射率的降低不是单调的，而是显示出振荡行为。
In situ measurements of the diffuse and specular reflectivity of GaAs substrates in molecular‐beam epitaxy show that the GaAs surface roughens during thermal desorption of the oxide and smooths during the growth of a buffer layer. The diffuse reflectivity increases abruptly over a temperature interval smaller than 0.4 °C as the oxide desorbs. This provides a convenient optical signature for determining when the substrate is clean. The oxide desorption temperature and the amount of surface roughening both increase with the thickness of the oxide. The decrease in the diffuse reflectivity during the growth of the buffer layer is not monotonic, showing instead an oscillatory behavior.