Method of forming thin film transistors on predominantly <100> polycrystalline silicon films
AssigneeSharp Laboratories of America, Inc.
InventorApostolos Voutsas
Life of this patent
Estimating the term…
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.
Claims12
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 crystallization process to produce a polycrystalline film having a predominantly <100> crystallographic orientation;
- d) polishing the polycrystalline film to a thickness of less than 100 nm;
- e) forming a gate structures over the polycrystalline film;
- and
- f) doping the polycrystalline film having a predominantly <100> crystallographic orientation to produce source regions and drain regions.
A thin film transistor (TFT) structure comprising:
- a) a substrate;
- b) a polycrystalline silicon film having a predominantly <100> crystallographic orientation overlying the substrate, wherein the polycrystalline silicon film is less than 100 nm thick;
- c) a gate structure overlying the polycrystalline silicon film;
- and
- d) source and drain regions formed by doping the polycrystalline silicon film.
Dependencies are inferred from the claim text.