An electron-beam excited plasma reactor was developed, where an electron-beam was transmitted into the reactor through an interface film from the source. The interface film of polyimide was abraded during the electron-beam transmission and the interface material was deposited on a substrate in the reactor. The abrasion phenomena were studied experimentally by using Monte Carlo simulation of electron-beam transmission in the film. At the condition of minimized abrasion, stable etching of the Si wafer in CF4 was realized under a negative bias condition.