Application And Mechanism Study Of Trans-dichloroethylene In Oxidation Furnace

DCE(C₂H₂CL₂)is widely used in semiconductor oxide furnace.It can remove metal ion in furnace quartz tube,fix metal ion in chip device,improve Si O₂ quality and affect silicon oxide growth speed.This paper studied different conditions of silicon DCE oxidation,the effect of DCE to STI oxidation and the quartz tube cleaning function of DCE.Following experiment was based on TEL aspha-8se high temperature furnace.In this paper,the effect of DCE flow rate change,different process temperature and different oxygen flow rate were studied.STI shape silicon oxidation speed with DCE was deeply studied.In the case of shallow trench holes issue,silicon oxidation speed on the side wall direction,the relationship between DCE flux and shallow trench holes,the effect of quartz hydroxyl concentration on silicon oxidation rate were studied.This paper studied metal ion concentration change in furnace quartz tube,DCE cleaning quartz tube theory,and periodic justification method.Base on many experiments,silicon oxidation speed increases with the increase of DCE flow rate,the oxygen flow rate and the process temperature.Hydroxyl(OH-)concentration affecting silicon oxidation with DCE reaction model was proposed.New quartz tube has defects.Oxygen atoms'not paired electron in quartz can adsorb H to forming OH-.It can accelerate the decomposition reaction of HCl to release H and Cl.More Cl atoms will penetrate silicon dioxide layer and reach the Si-Si O₂ interface to promote silicon oxidation speed.The sustainable time after DCE clean quartz tube can be accurately measured by TXRF(Total Reflection X-Ray Fluorescence Spectrometer)method.Ten days is proposed instead of one week basing on experiment tool process conditions.DCE CLEAN recipe was optimized to solve the problem of DCE residue.