MICROWAVE PLASMA CVD DEVICE HAVING IMPROVED MICROWAVE INTRODUCING WINDOW

摘要

PURPOSE:To perform formation of a deposited film continuously and stably by constituting a microwave introducing window of alpha-alumina contg. specified amount of a vitreous component in a microwave plasma CVD device. CONSTITUTION:The inside of a reaction vessel 101 is vacuumized and exhausted via an exhaust pipe 104 and a base body 105 is heated and held at prescribed temp. with a built-in heater and a gaseous raw material is introduced through a gas introducing pipe 108 and the inside of the reaction vessel is maintained at about <=1X10<-2>Torr degree of vacuum. Then a deposited film is formed on the electrically-conductive base body 105 by introducing microwave into a discharge space 106 via a waveguide 103 and a microwave introducing window 102. At this time, the introducing window 102 is constituted of alumina ceramics in which 1-10% vitreous component such as SiO2, CaO and MgO is incorporated and the other components substantially are alpha-alumina. Thereby the introducing window 102 excellent in durability and transmission efficiency is obtained and a deposited film is formed continuously and stably.