Thin-film semiconductor device fabrication method
AssigneeSeiko Epson Corporation
InventorsMitsutoshi Miyasaki, Hidetada Tokioka, Tetsuya Ogawa
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Abstract
In the thin-film semiconductor device fabrication method according to the present invention, after forming an amorphous semiconductor film, the film is crystallized in the solid phase state, then a portion of the semiconductor film is molten by irradiating it with a pulsed laser beam having an absorption coefficient in amorphous silicon that is greater than the absorption coefficient in polysilicon. Thereby, polycrystalline thin-film semiconductor devices having superior characteristics can be fabricated.
Claims35
A method of fabricating on a substrate a thin film semiconductor device that employs as the active layer a crystalline semiconductor film composed primarily of silicon (Si), the method comprising:
- a semiconductor film formation step in which an amorphous semiconductor film composed primarily of silicon (Si) is deposited on a substrate;
- a solid phase crystallization step in which said amorphous semiconductor film is crystallized in the solid phase to yield a solid phase crystallization film;
- and
- a laser irradiation step in which a pulsed laser beam irradiates said solid phase crystallization film to yield a crystalline semiconductor film;
- wherein the wavelength of said pulse laser beam is approximately 370 nm or more and approximately 710 nm or less.
A method of fabricating on a substrate a thin film semiconductor device that employs as the active layer a crystalline semiconductor film composed primarily of silicon (Si), the method comprising:
- a semiconductor film formation step in which an amorphous semiconductor film composed primarily of silicon (Si) is deposited on a substrate;
- a solid phase crystallization step in which said amorphous semiconductor film is crystallized in the solid phase to yield a solid phase crystallization film;
- and
- a laser irradiation step in which a pulsed laser beam having a wavelength of approximately 532 nm irradiates said solid phase crystallization film to yield a crystalline semiconductor film;
- wherein the irradiated energy intensity of said pulse laser beam on said solid phase crystallization film is approximately 100 mJ·cm−2 or more and approximately 1500 mJ·cm−2 or less.
A method of fabricating on a substrate a thin film semiconductor device that employs as the active layer a crystalline semiconductor film composed primarily of silicon (Si), the method comprising:
- a semiconductor film formation step in which an amorphous semiconductor film composed primarily of silicon (Si) is deposited on a substrate;
- a solid phase crystallization step in which said amorphous semiconductor film is crystallized in the solid phase to yield a solid phase crystallization film;
- and
- a laser irradiation step in which a pulsed laser beam having a wavelength of approximately 532 nm irradiates said solid phase crystallization film to yield a crystalline semiconductor film;
- wherein the irradiated energy intensity of said pulse laser beam on said solid phase crystallization film is approximately 600 mJ·cm−2 or more and approximately 1500 mJ·cm−2 or less.
A method of fabricating on a substrate a thin film semiconductor device that employs as the active layer a crystalline semiconductor film composed primarily of silicon (Si), the method comprising:
- a semiconductor film formation step in which an amorphous semiconductor film composed primarily of silicon (Si) is deposited on a substrate;
- a solid phase crystallization step in which said amorphous semiconductor film is crystallized in the solid phase to yield a solid phase crystallization film;
- and
- a laser irradiation step in which a pulsed laser beam having a wavelength of approximately 532 nm irradiates said solid phase crystallization film to yield a crystalline semiconductor film;
- wherein the irradiated energy intensity of said pulse laser beam on said solid phase crystallization film is approximately 100 mJ·cm−2 or more and approximately 850 mJ·cm−2 or less.
A method of fabricating on a substrate a thin film semiconductor device that employs as the active layer a crystalline semiconductor film composed primarily of silicon (Si), the method comrising:
- a semiconductor film formation step in which an amorphous semiconductor film composed primarily of silicon (Si) is deposited on a substrate;
- a solid phase crystallization step in which said amorphous semiconductor film is crystallized in the solid phase to yield a solid phase crystallization film;
- and
- a laser irradiation step in which a pulsed laser beam having a wavelength of approximately 532 nm irradiates said solid phase crystallization film to yield a crystalline semiconductor film;
- wherein the irradiated energy intensity of said pulse laser beam on said solid phase crystallization film is approximately 600 mJ·cm−2 or more and approximately 850 mJ·cm−2 or less.
A method of fabricating on a substrate a thin film semiconductor device that employs as the active layer a crystalline semiconductor film composed primarily of silicon (Si), the method comprising:
- a semiconductor film formation step in which an amorphous semiconductor film composed primarily of silicon (Si) is deposited on a substrate;
- a solid phase crystallization step in which said amorphous semiconductor film is crystallized in the solid phase to yield a solid phase crystallization film;
- and
- a laser irradiation step in which a pulsed laser beam irradiates said solid phase crystallization film to yield a crystalline semiconductor film;
- wherein said pulsed laser beam has an absorption coefficient in amorphous silicon that is greater than the absorption coefficient in polysilicon.
A method of fabricating on a substrate a thin film semiconductor device that employs as the active layer a crystalline semiconductor film composed primarily of silicon (Si), the method comprising:
- a semiconductor film formation step in which an amorphous semiconductor film composed primarily of silicon (Si) is deposited on a substrate to film thickness d (nm);
- a solid phase crystallization step in which said amorphous semiconductor film is crystallized in the solid phase to yield a solid phase crystallization film;
- and
- a laser irradiation step in which a pulsed laser beam having an absorption coefficient of μpSi that is 10−3 nm−1 or more and 10−2 nm−1 or less in polysilicon irradiates said solid phase crystallization film;
- wherein said film thickness d and said absorption coefficient μpSi satisfy the relationship:
- 0.105·μpSi−1<d<0.693·μpSi−1
A method of fabricating on a substrate a thin film semiconductor device that employs as the active layer a crystalline semiconductor film composed primarily of silicon (Si), the method comprising:
- a semiconductor film formation step in which an amorphous semiconductor film composed primarily of silicon (Si) is deposited on a substrate to film thickness d (nm);
- a solid phase crystallization step in which said amorphous semiconductor film is crystallized in the solid phase to yield a solid phase crystallization film;
- and
- a laser irradiation step in which a pulsed laser beam having an absorption coefficient of μpSi that is 10−3 nm−1 or more and 10−2 nm−1 or less in polysilicon irradiates said solid phase crystallization film;
- wherein said film thickness d and said absorption coefficient μpSi satisfy the relationship:
- 0.405μpSi−1<d<0.693·μpSi−1
A method of fabricating on a substrate a thin film semiconductor device that employs as the active layer a crystalline semiconductor film composed primarily of silicon (Si), the method comprising:
- a semiconductor film formation step in which an amorphous semiconductor film composed primarily of silicon (Si) is deposited on a substrate to film thickness of between approximately 25 nm and 165 nm;
- a solid phase crystallization step in which said amorphous semiconductor film is crystallized in the solid phase to yield a solid phase crystallization film;
- and
- a laser irradiation step in which the second harmonic frequency of a Nd:YAG laser beam irradiates said solid phase crystallization film.
Dependencies are inferred from the claim text.