VEECOMOCVD温度的测量与控制.ppt

MOCVD Process Temperature Measurement and ControlMOCVD工艺温度的测量与控制 Dr Sherman Li In-situ Measurements for Advanced Process Control Temperature Measurement for GaN For GaN Growth, the Substrate is Transparent Thermo-radiance from the wafer surface is not measurable The Challenge… To determine a reliable, repeatable method for measuring growth temperature The Solution… Veeco’s RealTemp? 200 for GaN in-situ growth monitoring and temperature measurement Temperature Measurement Options RealTemp? 200 In-Situ Measurement Accurate measurement of growth rate, buffer layer thickness, and roughness of recovery layer due to absolute reflectivity measurement In-situ measurement of refractive index allows the calculation of bulk ternary layer composition Temperature measurement is not affected by changing emissivity during growth - eliminating process drift Individual wafer measurement - temperature and reflectance plotted for each wafer RealTemp? 200 In-Situ Measurement Advantages Fast recovery after maintenance through reliable temperature and reflectance measurement data More accurate and repeatable run-to-run temperature measurement than standard pyrometers with minimal drift Full integration with EpiView software package provides layer markers and auto start/stop features In-Situ Hardware TurboDisc Operations Confidential Nearly all material structures require precise process control to achieve reproducible, high yield Why are in-situ measurements / control important? Iterative process to calibrate Reduce cycle - reduce cost Higher productivity Consistent results Growth Characterization Adjustment Calibration Cycle Veeco MOCVD tools have in-situ measurement and control capabilities which reduce the calibration cycle Wafer carrier with variable surface emissivity Pyrometer Thermocouple with non- repeatable temperature offset Surface of Substrate RealTemp? for III/V Emissivity Compensated Pyrometer Accurate Pocket Temperature RealTemp? 200 Wafer Wafer carriers rotate up to 1