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10 μm GaN外延片的940 nm、1 550 nm光谱发射率, 以Thomas Swan CSS MOCVD为例, 比较了500 ℃至1 300 ℃范围内, 940 nm单色辐射测温法、1 550 nm单色辐射测温法、940 nm与1 550 nm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940 nm与1 550 nm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: 940 nm与1 550 nm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940 nm单色辐射测温法和1 550 nm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 10 μm 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, 940 nm /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 940 nm /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 940 nm/1 550 nm double-wavelength colorimetric thermometry offers advantages 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.