Methods for depositing a microcrystalline silicon film for a photovoltaic device

A method of depositing a microcrystalline silicon film, comprising:

• flowing a gas mixture including a silane-based gas and H2 gas into a process chamber having a substrate disposed therein, the substrate having a surface area greater than about 1 square meter, wherein flowing the gas mixture further comprises:
• maintaining the process pressure at greater than about 3 Torr;
• and
• providing a substrate support assembly comprising a conductive body having an upper side for supporting the substrate and one or more cooling channels embedded within the conductive body to control the substrate temperature between about 100 degrees Celsius to about 400 degrees Celsius;
• maintaining a plasma formed from the gas mixture in the process chamber;
• and
• depositing a microcrystalline silicon film on the substrate while gradually reducing the ratio of H2 as to silane-based gas supplied in the gas mixture to de deposit the microcrystalline silicon film at a deposition rate greater than about 20 nm per minute, wherein the microcrystalline silicon film has a crystallized volume between about 20 percent to about 80 percent.

A method of depositing a microcrystalline silicon film, comprising:

• flowing a gas mixture including a silane-based gas and H2 gas into a process chamber having a substrate disposed therein, the substrate having a surface area greater than about 1 square meter;
• maintaining a plasma formed from the gas mixture in the process chamber;
• and depositing a microcrystalline silicon film on the substrate while gradually reducing the ratio of H2 gas to silane-based gas supplied in the gas mixture to deposit the microcrystalline silicon film at a deposition rate greater than about 20 nm per minute, wherein the microcrystalline silicon film has a crystallized volume between about 20 percent to about 80 percent;
• and
• maintaining a process spacing between a diffuser in the processing chamber and the substrate in a range between about 400 mils to about 1600 mils, wherein the diffuser has a plurality of orifices on a surface of the diffuser, wherein the orifices located in an inner region of the plurality of orifices have higher cavity volumes and densities than the orifices located in an outer region of the plurality of orifices.

A method of depositing a microcrystalline silicon film layer, comprising:

• flowing a gas mixture including a silane-based gas and H2 gas into a process chamber having a substrate therein, the substrate having a surface area greater than about 1 square meter;
• maintaining a plasma formed from the gas mixture in the process chamber;
• and
• depositing a microcrystalline silicon film on the substrate, comprising:
• depositing a microcrystalline silicon seed layer at a deposition rate of less than 20 nm per minute where the ratio of silane-based gas to H2 gas supplied in the gas mixture is between 1:100 and 1:2000;
• and
• depositing a microcrystalline silicon bulk layer at a deposition rate greater than 20 nm per minute while gradually reducing the ratio of H2 gas to silane-based gas supplied in the gas mixture;
• wherein the microcrystalline silicon film has a crystallized volume between about 20 percent to about 80 percent.

A method of forming photovoltaic device, comprising:

• forming a silicon based photoelectric converter on a substrate, wherein forming the photoelectric converter comprises:
• depositing a p-type semiconductor layer on a substrate in a process chamber;
• depositing an i-type semiconductor layer comprising a microcrystalline silicon film on the p-type semiconductor layer, wherein depositing the microcrystalline silicon film comprises:
• depositing a microcrystalline silicon seed layer at a deposition rate of less than 20 nm per minute where the ratio of silane-based gas to H2 gas supplied in the gas mixture is between 1:100 and 1:2000;
• and
• depositing a microcrystalline silicon bulk layer at a deposition rate greater than 20 nm per minute while gradually reducing the ratio of H2 gas to silane-based gas supplied in the gas mixture;
• wherein the microcrystalline silicon film has a crystallized volume between about 20 percent to about 80 percent;
• and
• depositing a n-type semiconductor layer on the i-type semiconductor layer.