Insulation film on semiconductor substrate and method for forming same

A method for forming an insulation film on a semiconductor substrate by plasma reaction, comprising the steps of:

• vaporizing a silicon-containing hydrocarbon compound to provide a source gas;
• introducing the source gas into a reaction space for plasma CVD processing wherein a semiconductor substrate is placed;
• introducing an additive gas selected from the group consisting of an inert gas and an oxidizing gas, said oxidizing gas being used in an amount less than the source gas, said source gas and said additive gas constituting a reaction gas;
• and
• forming an insulation film on the semiconductor substrate by activating plasma polymerization reaction in the reaction space, wherein the plasma polymerization reaction is activated while controlling the flow of the reaction gas to lengthen a residence time, Rt, of the reaction gas in the reaction space, wherein 100 msec≦Rt,
• Rt[s]=9.42×107(Pr·Ts/Ps·Tr)rw2d/F
• wherein:
• Pr:
• reaction space pressure (Pa)
• Ps:
• standard atmospheric pressure (Pa)
• Tr:
• average temperature of the reaction gas (K)
• Ts:
• standard temperature (K)
• rw:
• radius of the silicon substrate (m)
• d:
• space between the silicon substrate and the upper electrode (m)
• F:
• total flow volume of the reaction gas (sccm).