Method for forming a film

摘要

A method for forming a film is carried out by a film forming apparatus in which two cylindrical discharge electrodes are arranged opposite to each other at an inner wall and at an outer wall of an annular reaction chamber. A plurality of cylindrical substrates on which film is to be formed are arranged along the circumference in the region surrounded by the discharge electrodes. The substrate revolves about its own axis and additionally the substrate rotates with a platform. An electric power of 200 W is applied to the discharge electrode of the inner wall by an electric power supply having a frequency of 231 KHz, for example. An electric power of 600 W is applied to the discharge electrode at the outer wall by an electric power supply having a frequency of 400 KHz, for example. A reaction gas mainly in the form of SiH4 gas is introduced into the reaction chamber and the pressure in the reaction chamber is held at about 0.5 to 2.0 Torr. In this manner, the reaction gas is decomposed and an amorphous silicon film is formed on the outer cylindrical surface of the cylindrical substrates.