Method and system for evaluating polysilicon, and method and system for fabricating thin film transistor
AssigneeSony Corporation
InventorsHiroyuki Wada, Nobuhiko Umezu, Koichi Tatsuki
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Abstract
A method of evaluating a state of a polysilicon film objectively, accurately, automatically, and in a non-contact manner is provided. The method includes the steps of picking up a surface of a polysilicon film formed by excimer laser annealing, dividing the picked-up image into meshes each having a specific size, calculating a contrast in each of the meshes, extracting a highest contrast value and a lowest contrast value in the picked-up image, calculating a contrast ratio therebetween, and judging an average grain size of the polysilicon film on the basis of the contrast ratio.
Claims24
A polysilicon evaluating method of evaluating a polysilicon film formed by annealing an amorphous silicon film, comprising the steps of:
- picking up an image of a surface of the polysilicon film;
- dividing the picked-up image into a plurality of regions and calculating a contrast in each of the regions divided from the picked-up image;
- detecting a high contrast region and a low contrast region and comparing the contrasts in the high contrast and low contrast regions with each other;
- and
- evaluating a state of the polysilicon film on the basis of the comparison result.
A polysilicon evaluating system for evaluating a polysilicon film formed by annealing an amorphous silicon film, comprising:
- pick-up means of picking up an image of a surface of the polysilicon film;
- and
- evaluation means of dividing the picked-up image into a plurality of regions, calculating a contrast in each of the regions divided from the picked-up image, detecting a high contrast region and a low contrast region, comparing the contrasts in the high contrast and low contrast regions with each other, and evaluating the state of the polysilicon film on the basis of the comparison result.
A thin film transistor fabricating method of fabricating a thin film transistor, comprising:
- amorphous silicon forming step of forming an amorphous silicon film;
- polysilicon film forming step of forming a polysilicon film by annealing the amorphous silicon film;
- and
- evaluating step of picking up an image of a surface of the polysilicon film, dividing the picked-up image into a plurality of regions, calculating a contrast in each of the regions divided from the picked-up image, detecting a high contrast region and a low contrast region, comparing the contrasts in the high contrast and low contrast regions, and evaluating the state of the polysilicon film on the basis of the comparison result.
A thin film transistor fabricating system for fabricating a thin film transistor, comprising:
- an amorphous silicon forming device for forming an amorphous silicon film;
- a polysilicon film forming device for forming a polysilicon film by annealing the amorphous silicon film;
- and
- an evaluating device for picking up an image of a surface of the polysilicon film, dividing the picked-up image into a plurality of regions, calculating a contrast in each of the regions divided from the picked-up image, detecting a high contrast region and a low contrast region, comparing the contrasts in the high contrast and low contrast regions, and evaluating the state of the polysilicon film on the basis of the comparison result.
Dependencies are inferred from the claim text.