Patent ID: 7166335

Claim:
A layer formation method comprising the steps of supplying a discharge gas to a discharge space, exciting the supplied discharge gas at atmospheric pressure or at approximately atmospheric pressure by applying a high frequency electric field across the discharge space, transmitting the energy of the excited discharge gas to a layer formation gas such that the layer formation gas is in an excited state and exposing a substrate to the layer formation gas in the excited state, whereby a layer is formed on the substrate, wherein the high frequency electric field is an electric field in which a first high frequency electric field and a second high frequency electric field are superposed, frequency ω 2 of the second high frequency electric field is higher than frequency ω 1 of the first high frequency electric field, strength V 1 of the first high frequency electric field, strength V 2 of the second high frequency electric field and strength IV of discharge starting electric field satisfy relationship V 1 ≧IV>V 2 or V 1 >IV≧V 2 , and power density of the second high frequency electric field is not less than 1 W/cm 2 .