PURPOSE: To form a capacitor whose effective permittivity is large by a method wherein Ta(OC2H5)5 and an inert gas Ar are introduced into a vacuum chamber, a gas containing oxygen such as O2 or the like is not introduced and a tantalum oxide thin film is formed at a specific temperature or higher.
CONSTITUTION: A substrate 5 is attached to a substrate holder 15 and installed inside a vacuum chamber 1. The vacuum chamber 1 is made vacuum by an evacuation device and heated to about 600°C by a heater 6. The temperature of Ta(OC2H5)5 as an organic tantalum compound inside an ampule 3 is controlled to 120°C by a thermostatic tank 7, and an inert gas such as He, Ar or the like is bubbled by a flow-rate control device 8. In addition, the inert gas is heated to about 150°C by a heater 9 and introduced into the vacuum chamber 1 through an introduction pipe 10. A raw-material gas which has been introduced into the vacuum chamber 1 is pyrolyzed, reacted and deposited as a tantalum oxide thin film on the substrate 5. Thereby, it is possible to restrain that SiO2 is formed at the interface between polysilicon and the tantalum oxide thin film and to form a capacitor whose capacitance is large.
KITAGAWA MASATOSHI
KAMATA TAKESHI
HIRAO TAKASHI
