Method for manufacturing microcrystalline semiconductor film by plasma CVD apparatus

1. A method for manufacturing a microcrystalline semiconductor film, comprising the steps of:

forming a plasma region between a first electrode and a second electrode by supplying high-frequency power of 60 MHz or less to the first electrode under a condition where a pressure of a reactive gas in a reaction chamber of a plasma CVD apparatus is set to greater than or equal to 450 Pa and less than or equal to 13332 Pa, and a distance between the first electrode and the second electrode of the plasma CVD apparatus is set to greater than or equal to 1 mm and less than or equal to 20 mm;

forming crystalline deposition precursors in a gas phase including the plasma region;

forming a crystal nucleus of greater than or equal to 5 nm and less than or equal to 15 nm by depositing the crystalline deposition precursors over a substrate; and

forming a microcrystalline semiconductor film by growing a crystal from the crystal nucleus.

2. The method for manufacturing a microcrystalline semiconductor film according to claim 1 , wherein an electron temperature in the plasma region is reduced and an electron density in the plasma region is increased by adding a rare gas to the reactive gas, so that crystallinity of the microcrystalline semiconductor film is improved.

3. The method for manufacturing a microcrystalline semiconductor film according to claim 1 , further comprising the steps of:

forming a gate electrode over the substrate;

forming a gate insulating layer over the gate electrode;

forming the microcrystalline semiconductor layer over the gate insulating layer; and

forming a wiring electrically connected to the microcrystalline semiconductor layer.

4. A method for manufacturing a microcrystalline semiconductor film, using a plasma CVD apparatus provided with a first electrode and a second electrode in a reaction chamber, comprising the steps of:

introducing a reactive gas into the reaction chamber through a gas supply port in the first electrode provided with a plurality of projected portions;

setting a pressure of the reaction chamber to greater than or equal to 450 Pa and less than or equal to 13332 Pa;

setting a distance between the first electrode and the second electrode to greater than or equal to 1 mm and less than or equal to 20 mm;

forming a plasma region between the first electrode and the second electrode by supplying high-frequency power of 60 MHz or less to the first electrode;

forming crystalline deposition precursors including a semiconductor in a gas phase including the plasma region;

forming a crystal nucleus of greater than or equal to 5 nm and less than or equal to 15 nm by depositing the crystalline deposition precursors over a substrate; and

forming a microcrystalline semiconductor film by growing a crystal from the crystal nucleus.

5. The method for manufacturing a microcrystalline semiconductor film according to claim 4 , wherein the gas supply port is provided between the plurality of projected portions.

6. The method for manufacturing a microcrystalline semiconductor film according to claim 4 , wherein the gas supply port is provided on an apex of the plurality of projected portions.

7. The method for manufacturing a microcrystalline semiconductor film according to claim 4 , wherein an electron temperature in the plasma region is reduced and an electron density in the plasma region is increased by adding a rare gas to the reactive gas, so that crystallinity of the microcrystalline semiconductor film is improved.

8. The method for manufacturing a microcrystalline semiconductor film according to claim 4 , further comprising the steps of:

forming a gate electrode over the substrate;

forming a gate insulating layer over the gate electrode;

forming the microcrystalline semiconductor layer over the gate insulating layer; and

forming a wiring electrically connected to the microcrystalline semiconductor layer.

9. A method for manufacturing a microcrystalline semiconductor film, using a plasma CVD apparatus provided with an upper electrode and a lower electrode in a reaction chamber, comprising the steps of:

introducing a reactive gas into the reaction chamber;

setting a pressure of the reaction chamber to greater than or equal to 450 Pa and less than or equal to 13332 Pa;

forming a plasma region between the upper electrode and the lower electrode by supplying high-frequency power of 60 MHz or less to the upper electrode;

forming crystalline deposition precursors in a gas phase including the plasma region;

forming a crystal nucleus of greater than or equal to 5 nm and less than or equal to 15 nm by depositing the crystalline deposition precursors over a substrate; and

growing a crystal from the crystal nucleus,

wherein the upper electrode comprises:

a plurality of projected portions for forming glow discharge plasma in the reaction chamber by supplying the high-frequency power;

a first gas supply port provided on an apex of the plurality of projected portions; and

a second gas supply port provided between the plurality of projected portions,

wherein the plurality of projected portions have a tapered shape and are chamfered, and

wherein a distance between the upper electrode and the lower electrode is greater than or equal to 1 mm and less than or equal to 20 mm.

10. The method for manufacturing a microcrystalline semiconductor film according to claim 9 , wherein an electron temperature in the glow discharge plasma is reduced and an electron density in the glow discharge plasma is increased by adding a rare gas to the reactive gas, so that crystallinity of the microcrystalline semiconductor film is improved.

11. The method for manufacturing a microcrystalline semiconductor film according to claim 9 , further comprising the steps of:

forming a gate electrode over the substrate;

forming a gate insulating layer over the gate electrode;

forming the microcrystalline semiconductor layer over the gate insulating layer; and

forming a wiring electrically connected to the microcrystalline semiconductor layer.