Production process of semiconductor layer, fabrication process of photovoltaic cell and production apparatus of semiconductor layer

A process for producing a semiconductor layer by introducing a raw gas into a plurality of discharge chambers, supplying high-frequency power to the chambers to decompose the raw gas by discharge, and causing a substrate to successively pass through the discharge chambers, thereby forming a plurality of semiconductor layers on the substrate, the process comprising the steps of:

• supplying high-frequency power of very high frequency (VHF) as the high-frequency power to two or more discharge chambers of the plural discharge chambers;
• supplying bias power of different levels from each other to the discharge chambers, to which the high-frequency power of VHF is supplied, according to respective film-forming conditions in the discharge chambers;
• and
• controlling the electric potential of each electrode, to which the bias power is supplied, to the same level as that of the substrate or positive potential against the substrate.

A process for fabricating a photovoltaic cell, comprising the steps of introducing a raw gas into a discharge chamber and supplying high-frequency power to the chamber to decompose the raw gas by discharge, thereby forming an i-type semiconductor layer on a substrate within the discharge chamber, the process comprising the steps of:

• supplying high-frequency power of at least very high frequency (VHF) as the high-frequency power in the step of forming the i-type semiconductor layer;
• supplying bias power of direct current power and/or high-frequency power of radio-frequency (RF) together with the high-frequency power of VHF to the discharge chamber;
• and
• controlling a direct current component of an electric current flowing into an electrode, to which the bias power is supplied, so as to fall within a range of from 0.1 A/m2 to 10 A/m2 in terms of a current density based on the area of an inner wall of the discharge chamber.

A process for fabricating a photovoltaic cell by introducing a raw gas into a plurality of discharge chambers, supplying high-frequency power to the chambers to decompose the raw gas by discharge, and causing a substrate to successively pass through the discharge chambers, thereby at least forming a plurality of i-type semiconductor layers on the substrate, the process comprising the steps of:

• supplying high-frequency power of very high frequency (VHF) as the high-frequency power to two or more discharge chambers of the plural discharge chambers in which the respective i-type semiconductor layers are formed;
• supplying bias power of different levels from each other to the discharge chambers, to which the high-frequency power of VHF is supplied, according to respective film-forming conditions in the discharge chambers;
• and
• controlling the electric potential of each electrode, to which the bias power is supplied, to the same level as that of the substrate or positive potential against the substrate.

An apparatus for producing a semiconductor layer by introducing a raw gas into a discharge chamber and supplying high-frequency power to the chamber to decompose the raw gas by discharge, thereby forming a semiconductor layer on a substrate within the discharge chamber, the apparatus comprising:

• a means for supplying high-frequency power of at least very high frequency (VHF) as the high-frequency power;
• a means for supplying bias power of direct current power and/or high-frequency power of radio-frequency (RF) together with the high-frequency power of VHF to the discharge chamber;
• and
• a means for controlling a direct current component of an electric current flowing into an electrode, to which the bias power is supplied, so as to fall within a range of from 0.1 A/m2 to 10 A/m2 in terms of a current density based on the area of an inner wall of the discharge chamber.

An apparatus for producing a semiconductor layer by introducing a raw gas into a plurality of discharge chambers, supplying high-frequency power to the chambers to decompose the raw gas by discharge, and causing a substrate to successively pass through the discharge chambers, thereby forming a plurality of semiconductor layers on the substrate, the apparatus comprising:

• a means for supplying high-frequency power of very high frequency (VHF) as the high-frequency power to two or more discharge chambers of the plural discharge chambers;
• a means for supplying bias power of different levels from each other to the discharge chambers, to which the high-frequency power of VHF is supplied, according to respective film-forming conditions in the discharge chambers;
• and
• a means for controlling the electric potential of each electrode, to which the bias power is supplied, to the same level as that of the substrate or positive potential against the substrate.