Method for manufacturing microcrystalline semiconductor film and method for manufacturing semiconductor device
AssigneeSemiconductor Energy Labortory Co., Ltd.
InventorsSachiaki Tezuka, Yasuhiro Jinbo, Toshinari Sasaki, Hidekazu Miyairi
Life of this patent
Estimating the term…
Abstract
A method for manufacturing a semiconductor device having favorable electric characteristics with high productivity is provided. A first microcrystalline semiconductor film is formed over an oxide insulating film under a first condition that mixed phase grains with high crystallinity are formed at a low particle density. After that, a second microcrystalline semiconductor film is stacked over the first microcrystalline semiconductor film under a second condition that a space between the mixed phase grains are filled by the crystal growth of the mixed phase grains of the first microcrystalline semiconductor film.
Claims25
A method for manufacturing a microcrystalline silicon film, comprising the steps of:
- forming a first microcrystalline silicon film over an oxide insulating film by a plasma CVD method in the presence of a deposition gas containing silicon and a diluting gas containing hydrogen under a first condition;
- and
- forming a second microcrystalline silicon film over the first microcrystalline silicon film by a plasma CVD method in the presence of the deposition gas and the diluting gas under a second condition,
- wherein a flow ratio of the diluting gas to the deposition gas in the second condition is larger than that in the first condition, and
- wherein a pressure inside a process chamber in the second condition is larger than that in the first condition.
A manufacturing method of a semiconductor device comprising the steps of:
- forming a gate electrode;
- forming an oxide insulating film over the gate electrode;
- forming a first microcrystalline silicon film over the oxide insulating film by a plasma CVD method in the presence of a deposition gas containing silicon and a diluting gas containing hydrogen under a first condition;
- and
- forming a second microcrystalline silicon film over the first microcrystalline silicon film by a plasma CVD method in the presence of the deposition gas and the diluting gas under a second condition,
- wherein a flow ratio of the diluting gas to the deposition gas in the second condition is larger than that in the first condition, and
- wherein a pressure inside a process chamber in the second condition is larger than that in the first condition.
A semiconductor device comprising a thin film transistor, the thin film transistor comprising:
- a gate electrode;
- an oxide insulating film over the gate electrode;
- and
- a microcrystalline silicon film over the oxide insulating film,
- wherein the microcrystalline silicon film comprises a mixed phase grain including a silicon crystallite and amorphous silicon,
- wherein the mixed phase grain has a grain size greater than or equal to 2 nm and less than or equal to 200 nm.
A method for manufacturing a microcrystalline semiconductor film, comprising the steps of:
- forming a first microcrystalline semiconductor film over an oxide insulating film under a first condition that a density of mixed phase grains is decreased and a crystallinity of the mixed phase grains is improved;
- and
- forming a second microcrystalline semiconductor film over the first microcrystalline semiconductor film under a second condition that a space between the mixed phase grains of the first microcrystalline semiconductor film is filled and crystal growth is promoted.
Dependencies are inferred from the claim text.