The Devlelopment Of Online Temperature Measurement System During The Growth Of LED

Twelfth Five-Year National Semiconductor LED lighting plan greatly advanced metal-organic chemical vapor deposition equipment (Metal-Organic Chemical Vapor Deposition referred MOCVD) imports as well as localization development.MOCVD is a process method of manufacturing which based on a GaN-based LED epitaxial materials and chip Growth. And precise control of the process temperature determines the success or failure of the process, due to the complex and changing of technology growth environment, and can not contact LED for temperature measure, which leads to the process temperature control to become the industry difficult problem which has not yet been completely overcome. The basic measurement technology of process temperature has been abroad to master, the related products which have extraordinarily high prices failed tofully implement automatic temperature control. Industry thermometer which are customized depending on the device, also limits the the MOCVD industry independent research and development,At present industry MOCVD process temperature which basically depends on process engineering,has greatly hindered the advance of the MOCVD. In order to overcome this problem of process temperature measurement, Research Group specially set up this project.This thesis, starting from the theory of blackbody radiation, the goal is to achieve the real-time online temperature control of LED growth. Thesis work are as follows:(1) On the basis of the analysis of the theory of blackbody radiation,and collecting and analysis the process data,then put forward the goal of the project, as well as the challenges facing; Combined with the actual temperature control needs proposed solutions of online temperature control, with dual-channel single and double wavelength test method.At the same time aided design for system Optical path and mechanical structure parts.(2) According to the formula of Planck deduced the single and double wavelength temperature measurement algorithms,and proposed single wavelength temperature measurement correction algorithm to avoid installation (height and center offset) to influence the measurement result of temperature, and so provide protection for the system accurate temperature measurement. (3) Hardware design to achieve a dual-channel design compatible with single and double wavelength temperature measurement, simplify system design.(4) Actual inspect some parameters of growth process and the structure of MOCVD, the definition of software timing as well as the communication protocol to achieve accurate real-time temperature measurement and communication.(5) To make experimental prototype to do performance testing,and put forward algorithm which single point temperature pass to achieve a temperature from standard source transfer to the MOCVD chamber. The design test probability to use statistical methods to assess the performance of the system.Experimental prototype through the online process the growth temperature monitoring test, basically meet the company MOCVD real-time temperature needs and achieve the goal of thermometry:the temperature range of500-1200℃, accuracy0.1℃; With this monitoring system,MOCVD equipment growth Blu-ray GaN-based LED which achieve industry standards, and it greatly promotes the MOCVD process of localization.