Method of forming thin film transistors on predominantly <100> polycrystalline silicon films
AssigneeSharp Laboratories of America, Inc.
InventorApostolos Voutsas
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Abstract
A method is provided to produce thin film transistors (TFTs) on polycrystalline films having a single predominant crystal orientation. A layer of amorphous silicon is deposited over a substrate to a thickness suitable for producing a desired crystal orientation. Lateral-seeded excimer laser annealing (LS-ELA) is used to crystallize the amorphous silicon to form a film with a preferred crystal orientation. The crystallized film is then polished to a desired thickness. A gate is formed overlying the polycrystalline film. The polycrystalline film is doped to produce source and drain regions.
Claims7
A method of forming thin film transistor (TFT) structures on a substrate comprising the steps of;
- a) providing the substrate;
- b) depositing an amorphous silicon film at least 100 nm thick over the substrate;
- c) annealing the amorphous silicon film using a lateral-seeded ELA crystallization process to produce a polycrystalline film having a predominantly <100> crystallographic orientation in the rolling direction;
- d) polishing the polycrystalline film to a thickness of less than 100 nm;
- e) forming gate structures over the polycrystalline film;
- and
- f) doping the polycrystalline film having a predominantly <100> crystallographic orientation in the rolling direction to produce source regions and drain regions.
Dependencies are inferred from the claim text.