Thin-film device, thin-film device array, and method of manufacturing thin-film device

A thin-film device comprising:

• a substrate;
• and
• a first device unit and a second device unit which are located above the substrate,
• the first device unit including:
• a first gate electrode formed above the substrate;
• a first gate insulating film covering the first gate electrode;
• and
• a first thin film located opposite to the first gate electrode with the first gate insulating film in between, and
• the second device unit including:
• a second gate electrode located at a position different from a position where the first gate electrode is formed;
• a second gate insulating film covering the second gate electrode;
• and
• a second thin film located opposite to the second gate electrode with the second gate insulating film in between,
• wherein the first thin film includes a strip-shaped first area and a second area located on each widthwise side of the strip-shaped first area, the second area including crystal grains having an average grain size smaller than an average grain size of crystal grains included in the strip-shaped first area,
• the first device unit has a channel which is at least a part of the strip-shaped first area of the first thin film,
• the second thin film includes a third area including crystal grains having an average grain size smaller than the average grain size in the strip-shaped first area,
• the second device unit has a channel which is the third area, and
• the strip-shaped first area includes crystal grains which are in contact with the second area on the each side of the strip-shaped first area.

A method of manufacturing a thin-film device, the method comprising:

• preparing a substrate;
• forming a thin film above the substrate;
• crystallizing a part of the thin film through relative scan of the thin film irradiated with a first light beam at a predetermined speed;
• and
• crystallizing another part of the thin film through relative scan of the thin film irradiated with a second light beam at a predetermined speed,
• wherein each projection of the first light beam and the second light beam on the thin film has a major axis in a direction crossing a direction of the relative scan,
• the first light beam is shorter than the second light beam in width in the direction of the relative scan,
• the first thin film includes a strip-shaped first area and a second area located on each widthwise side of the strip-shaped first area, the second area including crystal grains having an average grain size smaller than an average grain size of crystal grains included in the strip-shaped first area,
• the first device unit has a channel which is at least a part of the strip-shaped first area of the first thin film,
• the second thin film includes a third area including crystal grains having an average grain size smaller than the average grain size in the strip-shaped first area,
• the second device unit has a channel which is the third area, and
• the strip-shaped first area includes crystal grains which are in contact with the second area on the each side of the strip-shaped first area.

A method of manufacturing a thin-film device, the method comprising:

• preparing a substrate;
• forming a first gate electrode above the substrate;
• forming a second gate electrode apart from the first gate electrode above the substrate;
• forming a gate insulating film above the first gate electrode and the second gate electrode;
• forming a thin film above the gate insulating film;
• crystallizing the thin film above the first gate electrode through relative scan of the thin film irradiated with a first laser beam from above the first gate electrode at a predetermined speed;
• and
• crystallizing the thin film above the second gate electrode through relative scan of the thin film irradiated with a second laser beam from above the second gate electrode at a predetermined speed,
• wherein each projection of the first light beam and the second light beam on the thin film has a major axis in a direction crossing a direction of the relative scan,
• a light absorptivity of the thin film above the first gate electrode with respect to the first light beam is higher than a light absorptivity of the thin film above the second gate electrode with respect to the second light beam,
• the first thin film includes a strip-shaped first area and a second area located on each widthwise side of the strip-shaped first area, the second area including crystal grains having an average grain size smaller than an average grain size of crystal grains included in the strip-shaped first area,
• the first device unit has a channel which is at least a part of the strip-shaped first area of the first thin film,
• the second thin film includes a third area including crystal grains having an average grain size smaller than the average grain size in the strip-shaped first area,
• the second device unit has a channel which is the third area, and
• the strip-shaped first area includes crystal grains which are in contact with the second area on the each side of the strip-shaped first area.

A method of manufacturing a thin-film device, the method comprising:

• preparing a substrate;
• forming a first gate electrode and a second gate electrode above the substrate;
• forming an insulating film above the first gate electrode and the second gate electrode;
• and
• forming, above the insulting film, a first channel area above the first gate electrode and a second channel area above the second gate electrode,
• wherein the forming of channel areas includes forming a precursor film above the insulating film, and emitting laser light to the precursor film through relative scan of the substrate irradiated with the laser light,
• the laser light is emitted in the emitting under a condition that a strip-shaped first area is formed on the precursor film that is not above the first gate electrode,
• when the laser light is positioned above the first gate electrode in the emitting, at least one of both end portions of the first gate electrode in a first direction is located within an emission width of the laser light in the first direction, the first direction crossing a scanning direction of the laser light,
• when the laser light is positioned above the second gate electrode in the emitting, both end portions of the second gate electrode in the first direction are located outside the emission width of the laser light in the first direction,
• the precursor film above the first gate electrode is lower in absorptivity with respect to the laser light than the precursor film that is not above the first gate electrode, and
• the precursor film above the second gate electrode is lower in absorptivity with respect to the laser light than the precursor film that is not above the second gate electrode.