【作者】 陈磊；

【导师】 王超；

【作者基本信息】 电子科技大学 ， 机械工程， 2016， 硕士

【摘要】 氮化镓是Ⅲ/Ⅴ族直接带隙半导体晶体,其在蓝光和紫光发射器件的研发领域起到了极大的促进作用。其在光电子、高频微波器件和功率电子器件应用方面前景十分美好。金属有机化合物气相沉积(Metal Organic Chemical Vapor Deposition,MOCVD)方法是最新一代化合物半导体器件制造的技术,MOCVD设备因其外延半导体器件的优良的品质和量产能力在工业上得到广泛的应用。由于近红外波长可透过氮化镓材料,故MOCVD设备外延生长氮化镓材料时,常用的红外测温仪只能测量外延片底部Pocket温度。但在外延生长量子阱对温度特别敏感,因此如何精确测量外延片表面温度有着重要的研究意义。本文对氮化镓外延生长表层温度在线监测方法做了详细的研究并设计测量仪器实现,主要研究内容如下:(1)分析了各种温度测量方法,根据氮化镓的材料特性选择采用测量近紫外波段热辐射强度方法进行氮化镓表层温度测量。研究微弱信号的测量方法以及根据信号与噪声的特点,寻找去除背景噪声的方法。(2)根据MOCVD设备结构特点,设计了氮化镓外延生长表层温度在线监测系统。通过垂直入射式探头光学和机械结构设计为其它在线监测设备安装节约了空间。同时通过抗振动与光路探头的大视场设计使得探头角度倾斜1°范围内,反射信号强度变化在2%以内。(3)在电路中实现了光电倍增管放大倍数控制与LED光源恒功率控制,光电倍增益管同时实现热辐射与反射率的测量。通过软件系统设计了针对不同温度条件下采用与当前温度对应条件下的光电倍增管信号放大倍数与LED光源的功率切换,使LED光源的反射光信号与当前温度下的热辐射信号强度处于相等数量级并有较强的输出信号。(4)对温度测量方法理论设计出的温度监测系统进行实验验证以及现场测试。通过实验结果分析,得到该温度监测系统温度测量范围在750~1200℃,重复性在1℃以内;低温段(750~870℃)范围内温度测量不确定度为3℃;高温段(870~1200℃)内温度测量精度在1℃以内时温度测量不确定度为0.5℃。其中1000℃以上时温度测量不确定度低于0.2℃。本文设计的氮化镓外延生长表层温度监测系统实现了氮化镓表层温度的测量,并用于中微半导体自主研发的Prismo D-Blue?485 MOCVD机台测试验证。更多还原

【Abstract】 Gallium nitride is the group Ⅲ/Ⅴ direct bandgap semiconductor crystal, which has played a great role in promoting research and development in the field of blue and violet light emitting device. It’s the third generation semiconductor material after the first generation material, Silicon and the second generation material GaAs, InP, which has broad prospects in optoelectronics, high-frequency microwave devices and high-power device applications. Metal Organic Chemical Vapor Deposition(MOCVD) method is the newest generation of compound semiconductor device manufacturing technology, MOCVD equipment are widely used in industry because of their excellent quality and high production capacity. But surface temperature measurement during GaN MOCVD is particularly difficult because the epilayers and substrates(typically sapphire) are transparent at the near-IR wavelengths normally used for pyrometry. In this paper we describe a method and ancillary equipment for monitoring the true surface temperature of the gallium nitride during it’s epitaxial growth. Thesis mainly investigated contents are as follows:(a) Analysis the different temperature measurement ways and find one solution is to detect radiation near 400 nm(UVviolet range, or UVV) where the GaN epilayers are opaque at the high temperatures encountered during deposition. Analysis the weak signal detection solutions and find ways to get rid of background noise according the feature of signal and noise.(b) Design on-line monitoring system testing and fixing method according to the structure of MOCVD device. Save space for another on-line monitoring equipment installation by designing optical and mechanical structure into normal incidence type. Large field of view and anti-vibration design of the optical path of the probe make sure the probe inclined at an angle within the range of 1°, the reflected signal intensity changes within 2%.(c) Achieve a photomultiplier tube amplification control and constant power control of LED light source, use one photomultiplier tube measuring thermal radiation and reflectivity and through the control of software to control the LED indensity to keep the same emitting indensity magnitude with thermal radiation..Through analysis the experiments and field test data with the temperature monitoring system, the temperature monitoring system temperature measurement range is 750 ~ 1200℃, repeatability within 1℃; Temperature measurement uncertainty is 3℃ during the range of 750 ~ 870℃; The temperature measurement accuracy within 1℃, temperature measurement uncertainty is 0.5℃ in the range of 870 ~ 1200℃. Wherein when more than 1000℃, temperature measurement uncertainty less than 0.2℃.。The temperature monitor system developed in this paper realized true surface temperature measurement and which has been verified in Prismo D-Blue? 485 MOCVD machine platform that is self-developed by AMEC.更多还原