Frequently asked questions: Ceiling / Window / Viewport
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What is the typical size of the ceiling or liner tube hole in horizontal MOCVD systems?
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about 6mm for EpiTT / EpiR DA, about 7x10 for EpiCurve Two TT
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What is the typical requirements for Aix CCS MOCVD systems?
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EpiTT and EpiTwin TT need a viewport which is located to inner 50% of the wafer at the according ring (crown) , best situation location at wafer center.
EpiCurve TT needs two viewport (minimum aperture 2mm) at the same crown. Since reflection and curvature optical heads needs to be mounted at separated viewports. -
What size must the view port have?
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The size of the viewport depends on the distance sample-viewport and on the amplitude of a potential sample wobble. Usually 2“ is sufficient, but please contact us and we will determine the needed size for your growth system.
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What material should the window be made of?
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The material of the window must be transparent for the spectroscopic range of the sensor used. In general we recommend quartz windows, as they are compatible with all our sensors.
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Are there special requirements for windows used for RAS measurements?
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Yes, low strain quartz windows are essential in this case.