FEEDBACK CONTROL SYSTEM FOR RAW MATERIAL FEED IN MOCVD SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a means in a practical stage in the feedback control of feeding raw materials of MOCVD (gas mixture containing solvent element). SOLUTION: A raw material feed control system performs in-line measurement of raw gas mixture to be fed via a vaporizer/mixer 6 so as to deposit an organic metal thin film (e.g., PZT film) of the target composition by an FTIR analyzer 11 in a preceding stage of a CVD apparatus 8. A feedback control panel 13 calculates the gas concentration (the actually measured concentration) for each composition by applying a component correction formula to the result of measurement of the raw gas mixture, obtains the feedback value as the operation quantity to a valve to adjust the feed of each raw solution by the formula of ((reference (target) concentration/actually measured concentration)-1)×(first MFC value (flow rate)/maximum MFC value (flow rate))×MFC resolution, and feeds back the result to the MFC 5 side. COPYRIGHT: (C)2004,JPO&NCIPI