US 2006/0186415 A1Published application

Thin film semiconductor device, method of manufacturing the same, and display

OwnerAkihiko Asanoinventor

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Abstract

Irradiation with laser light is conducted, whereby an external region of a semiconductor thin film located on the outer side relative to a pattern of a light absorbing layer is thermally melted, and the light absorbing layer is heated, without melting an internal region of the semiconductor thin film located on the inner side relative to the pattern. Next, the molten semiconductor thin film is cooled, whereby microcrystal grains are produced in the vicinity of the boundary between the external region and the internal region. Further, a first lateral crystal growth progresses from the boundary toward the outer side with the microcrystals as nuclei, whereby polycrystal grains are produced in an area of the external region. Finally, heat is transferred from the heated light absorbing layer to the semiconductor thin film, whereby the internal region is melted, and thereafter a second lateral crystal growth progresses from the boundary toward the inner side with the polycrystal grains as nuclei, whereby further enlarged polycrystal grains are produced in the internal region.

Claims17

Dependent claims

A method of manufacturing a thin film semiconductor device, comprising a light absorbing layer forming step for forming a light absorbing layer on the face side of a transparent substrate, a patterning step for patterning said light absorbing layer into a predetermined shape, an insulation film forming step for covering said patterned light absorbing layer with an insulation film, a semiconductor thin film forming step for forming a semiconductor thin film on said insulation film, and a laser annealing step for irradiating said substrate with laser light pulsedly oscillated from the back side of said substrate so as to crystallize said semiconductor thin film, wherein

said laser annealing step comprises:
a first process in which an external region of said semiconductor thin film located on the outer side relative to the pattern of said light absorbing layer is thermally melted, and said light absorbing layer is heated, without melting an internal region of said semiconductor thin film located on the inner side relative to the pattern of said light absorbing layer;
a second process in which said molten semiconductor thin film is cooled and microcrystal grains are produced in the vicinity of the boundary between said external region and said internal region;
a third process in which a first lateral growth progresses from said boundary between said external region and said internal region toward the outer side with said microcrystal grains as nuclei so that polycrystal grains greater than said microcrystal grains are produced in the area of said external region adjacent to said boundary;
and
a fourth process in which heat is transferred from said heated light absorbing layer to said semiconductor thin film through said insulation film, whereby said internal region is melted, and thereafter a second lateral growth progresses from said boundary toward the inner side with said polycrystal grains as nuclei so that further enlarged polycrystal grains are produced in said internal region.

3 more elements

A method of manufacturing a thin film semiconductor device, comprising a semiconductor thin film forming step for forming a semiconductor thin film on a substrate, an insulation film forming step for forming an insulation film thereon, a light absorbing layer forming step for forming a light absorbing layer on the upper side of said semiconductor thin film, with said insulation film therebetween, a patterning step for pattering said light absorbing layer into a predetermined shape, and a laser annealing step for irradiating said substrate with laser light pulsedly oscillated from the upper side of said substrate so as to crystallize said semiconductor thin film, wherein

said laser annealing step comprises:
a first process in which an external region of said semiconductor thin film located on the outer side relative to the pattern of said light absorbing layer is thermally melted, and said light absorbing layer is heated, without melting an internal region of said semiconductor thin film located on the inner side relative to the pattern of said light absorbing layer;
a second process in which said molten semiconductor thin film is cooled and microcrystal grains are produced in the vicinity of the boundary between said external region and said internal region;
a third process in which a first lateral growth progresses from said boundary between said external region and said internal region toward the outer side with said microcrystal grains as nuclei so that polycrystal grains greater than said microcrystal grains are produced in the area of said external region adjacent to said boundary;
and
a fourth process in which heat is transferred from said heated light absorbing layer to said semiconductor thin film through said insulation film, whereby said internal region is melted, and thereafter a second lateral growth progresses from said boundary toward the inner side with said polycrystal grains as nuclei so that further enlarged polycrystal grains are produced in said internal region.

3 more elements

A thin film semiconductor device comprising an insulating substrate provided integratedly with thin film transistors, wherein

each said thin film transistor comprises a semiconductor thin film and a gate electrode laminated, with a gate insulation film therebetween;
said semiconductor thin film comprises a channel region overlapping with said gate electrode, and a source region and a drain region which are located respectively on both sides of said channel region;
said semiconductor thin film is a polycrystalline layer crystallized by laser annealing, and is divided along the boundary of a predetermined pattern into an internal region and an external region;
said external region has a first lateral growth region containing polycrystal grains laterally grown from said boundary toward the outer side by said laser annealing;
said internal region has a second lateral growth region containing polycrystal grains laterally grown from said boundary toward the inner side with said polycrystalline contained in said first lateral growth region as nuclei;
and
said channel region is formed in said second lateral growth region.

4 more elements

A display comprising an insulating substrate provided integratedly with pixels and thin film transistors for driving said pixels, wherein

each said thin film transistor comprises a semiconductor thin film and a gate electrode laminated, with a gate insulation film therebetween;
said semiconductor thin film comprises a channel region overlapping with said gate electrode, and a source region and a drain region which are located respectively on both sides of said channel region;
said semiconductor thin film is a polycrystalline layer crystallized by laser annealing, and is divided along the boundary of a predetermined pattern into an internal region and an external region;
said external region has a first lateral growth region containing polycrystal grains laterally grown from said boundary toward the outer side by said laser annealing;
said internal region has a second lateral growth region containing polycrystal grains laterally grown from said boundary toward the inner side with said polycrystal grains contained in said first lateral growth region as nuclei;
and
said channel region is formed in said second lateral growth region.

4 more elements

Dependencies are inferred from the claim text.