Method for manufacturing microcrystalline semiconductor film and method for manufacturing semiconductor device

A method for manufacturing a microcrystalline semiconductor film, comprising:

• mixing a deposition gas containing silicon with hydrogen and applying high-frequency power to form a first microcrystalline semiconductor film over a substrate;
• exposing the first microcrystalline semiconductor film to plasma generated by applying high-frequency power in a rare gas atmosphere;
• exposing the first microcrystalline semiconductor film exposed to the plasma generated by applying the high-frequency power in the rare gas atmosphere to plasma generated by applying high-frequency power in an atmosphere containing hydrogen;
• and
• mixing a deposition gas containing silicon with hydrogen and applying high-frequency power to form a second microcrystalline semiconductor film over the first microcrystalline semiconductor film after exposing the first microcrystalline semiconductor film exposed to the plasma generated by applying the high-frequency power in the rare gas atmosphere to the plasma generated by applying the high-frequency power in the atmosphere containing hydrogen.

A method for manufacturing a microcrystalline semiconductor film, comprising:

• mixing a deposition gas containing silicon with hydrogen and applying high-frequency power to form a first microcrystalline semiconductor film over a substrate;
• exposing the first microcrystalline semiconductor film to plasma generated by applying high-frequency power in a rare gas atmosphere to form a second microcrystalline semiconductor film having an amorphous semiconductor region on a surface side;
• exposing the second microcrystalline semiconductor film to plasma generated by applying high-frequency power in an atmosphere containing hydrogen and removing the amorphous semiconductor region of the second microcrystalline semiconductor film to form a third microcrystalline semiconductor film;
• and
• mixing a deposition gas containing silicon with hydrogen and applying high-frequency power to form a fourth microcrystalline semiconductor film over the third microcrystalline semiconductor film.

A method for manufacturing a semiconductor device, comprising:

• forming a gate electrode over a substrate;
• forming a gate insulating film over the substrate and the gate electrode;
• mixing a deposition gas containing silicon with hydrogen and applying high-frequency power to form a first microcrystalline semiconductor film over the gate insulating film;
• performing treatment for flattening the first microcrystalline semiconductor film;
• performing treatment for removing a superficial layer of the flattened first microcrystalline semiconductor film;
• mixing a deposition gas containing silicon with hydrogen and applying high-frequency power to form a second microcrystalline semiconductor film over the first microcrystalline semiconductor film with the superficial layer removed;
• forming a semiconductor film including a microcrystalline semiconductor region and an amorphous semiconductor region, over the second microcrystalline semiconductor film;
• forming a first impurity semiconductor film over the semiconductor film;
• etching a part of the first impurity semiconductor film to form a second impurity semiconductor film;
• etching a part of the first microcrystalline semiconductor film, a part of the second microcrystalline semiconductor film, and a part of the semiconductor film to form a first semiconductor stack;
• forming wirings functioning as a source electrode and a drain electrode over the second impurity semiconductor film;
• and
• etching the second impurity semiconductor film to form a pair of impurity semiconductor films functioning as a source region and a drain region.

A method for manufacturing a photoelectric conversion device, comprising:

• forming a first electrode over a substrate;
• forming a semiconductor film having a first conductivity type over the first electrode;
• forming a semiconductor film having a function of photoelectric conversion over the semiconductor film having the first conductivity type;
• forming a semiconductor film having a second conductivity type over the semiconductor film having the function of photoelectric conversion;
• and
• forming a second electrode over the semiconductor film having the second conductivity type,
• wherein at least one of the semiconductor film having the first conductivity type, the semiconductor film having the function of photoelectric conversion, and the semiconductor film having the second conductivity type is formed by a method comprising:
• mixing a deposition gas containing silicon with hydrogen and applying high-frequency power to form a first microcrystalline semiconductor film;
• performing treatment for flattening the first microcrystalline semiconductor film;
• performing treatment for removing a superficial layer of the flattened first microcrystalline semiconductor film;
• and
• mixing a deposition gas containing silicon with hydrogen and applying high-frequency power to form a second microcrystalline semiconductor film over the first microcrystalline semiconductor film with the superficial layer removed.