MOCVD原位红外测温方法的比较研究

Comparative study on in situ infrared thermometry methods of MOCVD

MOCVD原位红外测温方法主要有单色辐射测温法与双波长比色测温法。利用薄膜等厚干涉模型与Kirchhoff定律计算了Si(111)衬底生长10μm GaN外延片的940nm、1 550nm光谱发射率,以Thomas Swan CSS MOCVD为例,比较了500℃至1 300℃范围内,940nm单色辐射测温法、1 550nm单色辐射测温法、940nm与1 550nm双波长比色测温法的相对误差和相对灵敏度,以及单色辐射测温法与双波长比色测温法的校准修正,并利用940nm与1 550nm双波长比色测温法在线监测了Si(111)衬底生长InGaN/GaN MQW结构LED外延片过程中的温度。研究表明:940nm与1 550nm双波长比色测温法在相对误差及有效探测孔径修正校准上优于940nm单色辐射测温法和1 550nm单色辐射测温法,该结论可为MOCVD原位红外测温设备开发提供参考。

The in situ infrared thermometry methods of metal organic chemical vapor deposition（MOCVD）mainly include monochromatic radiation thermometry and double-wavelength colorimetric thermometry.We calculated the 940 nm and 1 550 nm spectral emissivity of 10μm GaN on silicon（111）substrate by film thickness interference model and Kirchhoff＇s law,compared the relative error and relative sensitivity among 940 nm monochromatic radiation thermometry,1 550 nm monochromatic radiation thermometry,940nm/1 550 nm double-wavelength colorimetric thermometry within the scope of 500 ℃ to 1 300 ℃ by taking the Thomas Swan CSS MOCVD as an example,as well as the calibration betweenmonochromatic radiation thermometry and double-wavelength colorimetric thermometry.Moreover,by using the 940nm/1 550 nm double-wavelength colorimetric thermometry,the temperature of LED epitaxial wafer with InGaN/GaN MQW structure growing on silicon（111）substrate was monitored on-line.The result shows that the 940nm/1 550 nm double-wavelength colorimetric thermometry offers ad-vantages over the 940 nm and 1 550 nm monochromatic radiation thermometry in terms of relative error and correction.The conclusion can provide reference for the in situ infrared thermometry design of MOCVD.