JPH0918006A - Thin film transistor and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lessen the deterioration and irregularity in threshold voltage and the mobility of a thin film transistor by a method wherein the cross-sectional shape of a source-drain electrode is formed in a structure having a step. SOLUTION: A source and drain electrode 13 is provided on an insulative board 11. The pattern size of the photoresist 27 to be formed on the source and drain electrode 13 is made larger by softening it, a stepped source and drain electrode 13 is formed, and its cross-sectional shape is stepwisely formed. When a stepped part is formed as above-mentioned on the source and drain electrode, the step size of the semiconductor film 15 provided on its upper layer can be decreased. As a result, in the side face region of the patterned source and drain electrode 13 and the board 11, the turbulence of crystallizability caused by the difference in growth direction of the film which becomes the semiconductor film 15 can be alleviated. Accordingly, the characteristics of a thin film transistor, especially the deterioration and irregularity of the characteristics of a thin film transistor can be lessened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a thin film transistor formed on an insulating substrate or an insulating film,
And a manufacturing method for forming the structure.

[0002]

2. Description of the Related Art A thin film transistor formed on an insulating substrate or an insulating film is used for a switching element, a sensor and a three-dimensional circuit element of an active matrix type liquid crystal display device. The structure and manufacturing method of this thin film transistor will be described with reference to the sectional view of FIG.

As shown in FIG. 27, a source / drain electrode 13 is provided on an insulating substrate 11 so as to form a gap therebetween. Furthermore, this source / drain electrode 1
The semiconductor film 15 is provided so as to overlap 3. This semiconductor film 15 becomes the active region of the thin film transistor.

Further, a gate insulating film 17 is provided on the semiconductor film 15, and a gate electrode 19 is further provided on the gate insulating film 17. As a result, a thin film transistor having a metal-insulating film-semiconductor structure is obtained.

[0005]

In the thin film transistor shown in FIG. 27, the thin film transistor can be formed by two photomasks. That is, a photomask for patterning the source / drain electrode 13, a semiconductor film 15, a gate insulating film 17, and a gate electrode 19
The thin film transistor can be formed by using two photomasks including a photomask for patterning with.

Therefore, the thin film transistor as shown in FIG. 27 has an advantage that its manufacturing process is simplified.
However, this thin film transistor has a problem due to the cross-sectional shape of the source / drain electrode 13 as described below.

That is, the cross-sectional shape of the source / drain electrode 13 of the thin film transistor in the prior art is rectangular, and the film quality of the semiconductor film 15 provided so as to overlap the source / drain electrode 13 deteriorates in the overlap region.

As shown in FIG. 27, the side surface region of the patterned source / drain electrode 13 and the substrate 11 have different growth directions of the film to be the semiconductor film 15. Therefore, in the boundary region, the different growth directions of the coating film collide with each other, and the crystallinity is disturbed.

If there is a region where the crystallinity of the semiconductor film 15 which is the active region of the thin film transistor is disturbed,
The characteristics of the thin film transistor, especially the deterioration of the threshold voltage and the mobility and the variation thereof become large.

An object of the present invention is to solve the above problems and provide a structure of a thin film transistor having good characteristics and a method of manufacturing the thin film transistor.

[0011]

In order to achieve the above object, the structure of the thin film transistor of the present invention and the manufacturing method thereof adopt the following means.

The thin film transistor of the present invention comprises a source / drain electrode provided on a substrate, a semiconductor film provided on the source / drain electrode, and a gate insulating film provided on the semiconductor film.
A source electrode and a gate electrode provided on the gate insulating film, and the source / drain electrode has a step shape in cross section.

The thin film transistor of the present invention comprises a source / drain electrode provided on a substrate, an intermediate film provided on the source / drain electrode, a semiconductor film provided on the intermediate film, a gate insulating film provided on the semiconductor film, and a gate insulating film. And a gate electrode provided on the source / drain electrode, and the source / drain electrode has a step-shaped cross section.

A thin film transistor of the present invention comprises a source / drain electrode provided on a substrate, an intermediate film containing impurities provided on the source / drain electrode, a semiconductor film provided on the intermediate film, and a gate insulating film provided on the semiconductor film. And a gate electrode provided on the gate insulating film, and the source / drain electrode has a step-shaped cross section.

The thin film transistor of the present invention comprises a light-shielding film provided on a substrate, an interlayer insulating film provided on the light-shielding film, a source / drain electrode provided on the interlayer insulating film, a semiconductor film provided on the source / drain electrode, and a semiconductor. A gate insulating film provided over the film and a gate electrode provided over the gate insulating film are provided, and the source / drain electrode has a step shape in cross section.

The thin film transistor of the present invention comprises a light-shielding film provided on a substrate, an interlayer insulating film provided on the light-shielding film, a source / drain electrode provided on the upper surface of the interlayer insulating film, an intermediate film provided on the source / drain electrode, and an intermediate film. A semiconductor film provided over the film, a gate insulating film provided over the semiconductor film, and a gate electrode provided over the gate insulating film are provided, and the source / drain electrode has a step shape in cross section.

The thin film transistor of the present invention comprises a light-shielding film provided on a substrate, an interlayer insulating film provided on the light-shielding film, a source / drain electrode provided on the interlayer insulating film, and an intermediate film containing impurities provided on the source / drain electrode. A semiconductor film provided on the intermediate film, a gate insulating film provided on the semiconductor film,
A source electrode and a gate electrode provided on the gate insulating film, and the source / drain electrode has a step shape in cross section.

The thin film transistor of the present invention comprises a light-shielding film and a capacitor lower electrode provided on a substrate, an interlayer insulating film provided on the light-shielding film and the capacitor lower electrode, a source drain electrode provided on the interlayer insulating film, and a source drain electrode. And a gate insulating film provided on the semiconductor film, and a gate electrode provided on the gate insulating film, and the source / drain electrode has a step shape in cross section.

The thin film transistor of the present invention comprises a light-shielding film and a capacitor lower electrode provided on a substrate, an interlayer insulating film provided on the light-shielding film and the capacitor lower electrode, a source drain electrode provided on the interlayer insulating film, and a source drain electrode. And a semiconductor film provided on the intermediate film, a gate insulating film provided on the semiconductor film, and a gate electrode provided on the gate insulating film, and the source / drain electrode has a step shape in cross section. And

The thin film transistor of the present invention comprises a light-shielding film and a capacitor lower electrode provided on a substrate, an interlayer insulating film provided on the upper surface of the light-shielding film and the capacitor lower electrode, a source drain electrode provided on the interlayer insulating film, and a source drain electrode. An intermediate film containing impurities, a semiconductor film provided on the intermediate film, a gate insulating film provided on the semiconductor film, and a gate electrode provided on the gate insulating film, and the source / drain electrode has a step shape in cross section. It is characterized by

The thin film transistor of the present invention comprises a light-shielding film and a capacitor lower electrode provided on a substrate, an oxide film provided on the upper surface of the capacitor lower electrode, an interlayer insulating film provided on the light-shielding film and the oxide film.
The source / drain electrode provided on the interlayer insulating film, the semiconductor film provided on the source / drain electrode, the gate insulating film provided on the semiconductor film, and the gate electrode provided on the gate insulating film are provided. It is characterized by having a step.

The thin film transistor of the present invention comprises a light-shielding film provided on a substrate, a capacitor lower electrode, an oxide film provided on the capacitor lower electrode, an interlayer insulating film provided on the light-shielding film and the oxide film, and an interlayer insulating film provided on the interlayer insulating film. The source / drain electrode includes a source / drain electrode provided, an intermediate film provided on the source / drain electrode, a semiconductor film provided on the intermediate film, a gate insulating film provided on the semiconductor film, and a gate electrode provided on the gate insulating film. The cross-sectional shape of has a step.

The thin film transistor of the present invention includes a light-shielding film and a capacitor lower electrode provided on a substrate, an oxide film provided on the capacitor lower electrode, an interlayer insulating film provided on the light-shielding film and the oxide film, and an interlayer insulating film. A source / drain electrode, an intermediate film containing impurity ions provided on the source / drain electrode, a semiconductor film provided on the intermediate film, a gate insulating film provided on the semiconductor film, and a gate electrode provided on the gate insulating film, The cross-sectional shape of the source / drain electrode has a step.

The method of manufacturing the thin film transistor of the present invention is
The source / drain electrode material is formed on the substrate, the photoresist is formed on the source / drain electrode material, the source / drain electrode material is etched by using the photoresist as an etching mask, the photoresist is ashed, and the photoresist is further removed. A step of forming a source / drain electrode by etching to the middle of the film thickness of the source / drain electrode material using an etching mask, and a semiconductor film material, a gate insulating film material, and a gate electrode material are sequentially formed,
Forming a photoresist on the gate electrode material,
And a step of etching the semiconductor film material, the gate insulating film material, and the gate electrode material using a photoresist as an etching mask to form the semiconductor film, the gate insulating film, and the gate electrode.

The method of manufacturing the thin film transistor of the present invention comprises:
A source / drain electrode material and an intermediate film are formed on a substrate, a photoresist is formed on the intermediate film, the intermediate film and the source / drain electrode material are etched using the photoresist as an etching mask, and the photoresist is ashed. Further, using the photoresist as an etching mask, the intermediate film is etched, and the source / drain electrode is formed by etching to the middle of the film thickness of the source / drain electrode material, and the semiconductor film material, the gate insulating film material, and the gate electrode material. And sequentially forming a photoresist on the gate electrode material, and using the photoresist as an etching mask to etch the semiconductor film material, the gate insulating film material, and the gate electrode material to form the semiconductor film and the gate insulating film. And a step of forming a gate electrode.

The method for manufacturing a thin film transistor according to the present invention comprises:
A source / drain electrode material is formed on the substrate, a photoresist is formed on the source / drain electrode material, the photoresist is used as an etching mask to etch the source / drain electrode material up to the middle of its thickness, and the photoresist is ashed. Further, a step of etching the source / drain electrode material by using a photoresist as an etching mask to form a source / drain electrode, a semiconductor film material, a gate insulating film material, and a gate electrode material are sequentially formed, and the step is performed on the gate electrode material. And a step of forming a semiconductor film, a gate insulating film, and a gate electrode by etching the semiconductor film material, the gate insulating film material, and the gate electrode material using the photoresist as an etching mask. It is characterized by

The thin film transistor manufacturing method of the present invention is
A source / drain electrode material and an intermediate film are formed on the substrate, a photoresist is formed on the intermediate film, the intermediate film is etched by using the photoresist as an etching mask, and the source / drain electrode material is partially etched. ,
The steps of ashing the photoresist, etching the intermediate film and the source / drain electrode material by using the photoresist as an etching mask to form the source / drain electrode, and the semiconductor film material, the gate insulating film material, and the gate electrode material are performed. A step of sequentially forming a photoresist on the gate electrode material, and a semiconductor film material, a gate insulating film material, and a gate electrode material by etching the semiconductor film material, the gate insulating film material, and the gate electrode material using the photoresist as an etching mask. And a step of forming an electrode.

The method of manufacturing a thin film transistor of the present invention is
A source / drain electrode material is formed on the substrate, a photoresist is formed on the source / drain electrode material, the photoresist is used as an etching mask to etch the source / drain electrode material up to the middle of the film thickness, and the photoresist is heat-treated. Softening, and then using the photoresist as an etching mask to etch the source / drain electrode material to form the source / drain electrode, a semiconductor film material, a gate insulating film material, and a gate electrode material are sequentially formed to form a gate electrode. Forming a photoresist on the material, and forming a semiconductor film, a gate insulating film, and a gate electrode by etching the semiconductor film material, the gate insulating film material, and the gate electrode material using the photoresist as an etching mask And having.

The method of manufacturing a thin film transistor of the present invention is
A source / drain electrode material is formed on a substrate, a first photoresist is formed on the source / drain electrode material, the source / drain electrode material is etched using the photoresist as an etching mask, and the first photoresist is removed. Further, a second photoresist having a pattern size smaller than that of the first photoresist is formed on the source / drain electrode material, and the second photoresist is used as an etching mask to etch the source / drain electrode material to the middle of its thickness. To form a source / drain electrode, a step of sequentially forming a semiconductor film material, a gate insulating film material, and a gate electrode material, and forming a photoresist on the gate electrode material; and a semiconductor using the photoresist as an etching mask. Semiconductor by etching film material, gate insulating film material, and gate electrode material Characterized by a step of forming a gate insulating film and a gate electrode and.

The method of manufacturing the thin film transistor of the present invention comprises
A source / drain electrode material is formed on a substrate, a first photoresist is formed on the source / drain electrode material, and the source / drain electrode material is etched to the middle of the film thickness by using the photoresist as an etching mask. The photoresist is removed, a second photoresist having a smaller pattern size than the first photoresist is formed on the source / drain electrode material, and the source / drain electrode material is etched using the second photoresist as an etching mask. To form a source / drain electrode, a step of sequentially forming a semiconductor film material, a gate insulating film material, and a gate electrode material, and forming a photoresist on the gate electrode material; and a semiconductor using the photoresist as an etching mask. Semiconductor by etching film material, gate insulating film material, and gate electrode material Characterized by a step of forming a gate insulating film and a gate electrode and.

The method of manufacturing the thin film transistor of the present invention is
Forming a source / drain electrode material on the substrate and forming a first photoresist on the source / drain electrode material;
Is used as an etching mask to etch the source / drain electrode material up to the middle of the film thickness, the first photoresist is removed, and the source / drain electrode material having a second pattern having a larger pattern dimension than the first photoresist is removed. And forming a source / drain electrode by etching the source / drain electrode material using the second photoresist as an etching mask.
A step of sequentially forming a semiconductor film material, a gate insulating film material, and a gate electrode material, and forming a photoresist on the gate electrode material; and a semiconductor film material, a gate insulating film material, and a gate electrode using the photoresist as an etching mask. And a step of forming a semiconductor film, a gate insulating film, and a gate electrode by etching a material.

The method of manufacturing the thin film transistor of the present invention is
A step of forming a light-shielding film material on a substrate, forming a photoresist on the light-shielding film material, etching the light-shielding film material using the photoresist as an etching mask to form a light-shielding film, and forming an interlayer insulating film; , Forming a source / drain electrode material on the interlayer insulating film, forming a photoresist on the source / drain electrode material, etching the source / drain electrode material using the photoresist as an etching mask, and ashing the photoresist, Further, a step of forming a source / drain electrode by etching the source / drain electrode material to the middle of the film thickness using a photoresist as an etching mask, a semiconductor film material, a gate insulating film material, and a gate electrode material are sequentially formed, and a gate is formed. Step of forming photoresist on electrode material and etching mask of photoresist Characterized by a step of forming a semiconductor film and the gate insulating film and the gate electrode by etching the semiconductor film material and the gate insulating film material and the gate electrode material using.

The method of manufacturing a thin film transistor according to the present invention comprises:
A step of forming a light-shielding film material on a substrate, forming a photoresist on the light-shielding film material, etching the light-shielding film material using the photoresist as an etching mask to form a light-shielding film, and forming an interlayer insulating film; , A source / drain electrode material and an intermediate film are formed on this interlayer insulating film, a photoresist is formed on the intermediate film, and the intermediate film and the source / drain electrode material are etched using the photoresist as an etching mask to remove the photoresist. A step of forming a source / drain electrode by ashing and then etching the intermediate film and the source / drain electrode material up to the middle of the film thickness using a photoresist as an etching mask; a semiconductor film material, a gate insulating film material, and a gate electrode material And then sequentially forming a photoresist on the gate electrode material and etching the photoresist. Characterized by a step of forming a semiconductor film and the gate insulating film and the gate electrode by etching the semiconductor film material and the gate insulating film material and the gate electrode material using the mask.

The method of manufacturing the thin film transistor of the present invention comprises:
A step of forming a light-shielding film material on a substrate, forming a photoresist on the light-shielding film material, etching the light-shielding film material using the photoresist as an etching mask to form a light-shielding film, and forming an interlayer insulating film; , A source / drain electrode material is formed on this interlayer insulating film, a photoresist is formed on the source / drain electrode material, and the photoresist is used as an etching mask to etch the source / drain electrode material up to the middle of the film thickness. Ashing, and a step of etching the source / drain electrode material by using the photoresist as an etching mask to form the source / drain electrode; a semiconductor film material, a gate insulating film material, and a gate electrode material are sequentially formed, and a gate is formed. Step of forming photoresist on electrode material and etching mask of photoresist Characterized by a step of forming a semiconductor film and the gate insulating film and the gate electrode by etching the semiconductor film material and the gate insulating film material and the gate electrode material using.

The method of manufacturing the thin film transistor of the present invention comprises:
A step of forming a light-shielding film material on a substrate, forming a photoresist on the light-shielding film material, etching the light-shielding film material using the photoresist as an etching mask to form a light-shielding film, and forming an interlayer insulating film; , The source / drain electrode material and the intermediate film are formed on the interlayer insulating film, the photoresist is formed on the intermediate film, and the photoresist is used as an etching mask to etch the intermediate film and the source / drain electrode material to the middle of the film thickness. And ashing the photoresist, and etching the intermediate film and the source / drain electrode material by using the photoresist as an etching mask to form the source / drain electrode, and the semiconductor film material, the gate insulating film material, and the gate electrode material. And then sequentially forming a photoresist on the gate electrode material and etching the photoresist. Characterized by a step of forming a semiconductor film and the gate insulating film and the gate electrode by etching the semiconductor film material and the gate insulating film material and the gate electrode material using the mask.

The method of manufacturing the thin film transistor of the present invention is
A step of forming a light-shielding film material on a substrate, forming a photoresist on the light-shielding film material, etching the light-shielding film material using the photoresist as an etching mask to form a light-shielding film, and forming an interlayer insulating film; , A source / drain electrode material is formed on the interlayer insulating film, a photoresist is formed on the source / drain electrode material, and the photoresist is used as an etching mask to etch the source / drain electrode material up to the middle of the film thickness to remove the photoresist. A step of forming a source / drain electrode by heat treatment to soften the material and further etching the source / drain electrode material using a photoresist as an etching mask, and a semiconductor film material, a gate insulating film material, and a gate electrode material are sequentially formed. , A step of forming a photoresist on the gate electrode material, and an etching mask for the photoresist Characterized by a step of forming a semiconductor film and the gate insulating film and the gate electrode by etching the semiconductor film material and the gate insulating film material and the gate electrode material using.

The method of manufacturing the thin film transistor of the present invention comprises:
A step of forming a light-shielding film material on a substrate, forming a photoresist on the light-shielding film material, etching the light-shielding film material using the photoresist as an etching mask to form a light-shielding film, and forming an interlayer insulating film; Forming a source / drain electrode material on the interlayer insulating film, forming a first photoresist on the source / drain electrode material, and etching the source / drain electrode material using the photoresist as an etching mask to form a first photoresist. Is removed, and a second photoresist having a pattern size smaller than that of the first photoresist is formed on the source / drain electrode material, and the second photoresist is used as an etching mask in the middle of the film thickness of the source / drain electrode material. To form the source / drain electrodes by etching up to the semiconductor film material, the gate insulating film material, and the gate electrode. A step of sequentially forming a material and a photoresist on the gate electrode material, and a step of etching the semiconductor film material, the gate insulating film material, and the gate electrode material using the photoresist as an etching mask to form the semiconductor film and the gate insulating material. And a step of forming a film and a gate electrode.

The method of manufacturing the thin film transistor of the present invention comprises:
A step of forming a light-shielding film material on a substrate, forming a photoresist on the light-shielding film material, etching the light-shielding film material using the photoresist as an etching mask to form a light-shielding film, and forming an interlayer insulating film; , Forming a source / drain electrode material on the interlayer insulating film, forming a first photoresist on the source / drain electrode material, and etching the source / drain electrode material to the middle of the film thickness using the photoresist as an etching mask, Remove the first photoresist,
Further, a second photoresist having a pattern size smaller than that of the first photoresist is formed on the source / drain electrode material, and the source / drain electrode material is etched by using the second photoresist as an etching mask to form a source / drain electrode. And a step of sequentially forming a semiconductor film material, a gate insulating film material, and a gate electrode material, and forming a photoresist on the gate electrode material, and a semiconductor film material and a gate insulating film using the photoresist as an etching mask. And a step of etching the material and the gate electrode material to form a semiconductor film, a gate insulating film, and a gate electrode.

The method of manufacturing the thin film transistor of the present invention is
A step of forming a light-shielding film material on a substrate, forming a photoresist on the light-shielding film material, etching the light-shielding film material using the photoresist as an etching mask to form a light-shielding film, and forming an interlayer insulating film; , A source / drain electrode material is formed on the interlayer insulating film, a first photoresist is formed on the source / drain electrode material, and the first photoresist is used as an etching mask in the middle of the film thickness of the source / drain electrode material. Etching to remove the first photoresist, form a second photoresist having a pattern size larger than that of the first photoresist on the source / drain electrode material, and use the second photoresist as an etching mask. Step of etching source / drain electrode material to form source / drain electrode, semiconductor film material and gate insulating film material A step of sequentially forming a gate electrode material and forming a photoresist on the gate electrode material; and a step of etching the semiconductor film material, the gate insulating film material, and the gate electrode material using the photoresist as an etching mask to form a semiconductor film. And a step of forming a gate insulating film and a gate electrode.

The method of manufacturing the thin film transistor of the present invention comprises
A material for the light-shielding film and the lower capacitor electrode is formed on the substrate, a photoresist is formed on the material for the light-shielding film and lower capacitor electrode, and the light-shielding film and the lower capacitor electrode are formed by using the photoresist as an etching mask. A step of etching the material to form a light-shielding film and a capacitor lower electrode, forming an interlayer insulating film, and forming a source / drain electrode material on the interlayer insulating film,
Forming a photoresist on the source / drain electrode material,
The source / drain electrode material is etched using the photoresist as an etching mask, the photoresist is ashed, and the source / drain electrode is formed by etching the source / drain electrode material halfway through the photoresist as an etching mask. And a step of sequentially forming a semiconductor film material, a gate insulating film material, and a gate electrode material, and forming a photoresist on the gate electrode material, and a semiconductor film material and a gate insulating film using the photoresist as an etching mask. And a step of etching the material and the gate electrode material to form a semiconductor film, a gate insulating film, and a gate electrode.

The method of manufacturing the thin film transistor of the present invention is
A material for the light-shielding film and the lower capacitor electrode is formed on the substrate, a photoresist is formed on the material for the light-shielding film and lower capacitor electrode, and the light-shielding film and the lower capacitor electrode are formed by using the photoresist as an etching mask. A step of forming a light shielding film and a capacitor lower electrode by etching the material, forming an interlayer insulating film, forming a source / drain electrode material and an intermediate film on the interlayer insulating film, and forming a photoresist on the intermediate film, The photoresist is used as an etching mask to etch the intermediate film and the source / drain electrode material, the photoresist is ashed, and the photoresist is used as an etching mask to etch the intermediate film and the source / drain electrode material to the middle of the film thickness. Forming a source / drain electrode, a semiconductor film material, a gate insulating film material, and a gate electrode material are sequentially formed. And forming a semiconductor film, a gate insulating film, and a gate electrode by etching the semiconductor film material, the gate insulating film material, and the gate electrode material using the photoresist as an etching mask. And a step of performing.

The method of manufacturing the thin film transistor of the present invention is as follows.
A material for the light-shielding film and the lower capacitor electrode is formed on the substrate, a photoresist is formed on the material for the light-shielding film and lower capacitor electrode, and the light-shielding film and the lower capacitor electrode are formed by using the photoresist as an etching mask. The step of etching the material to form a light-shielding film and a capacitor lower electrode, forming an oxide film on the capacitor lower electrode and forming an interlayer insulating film, and forming a source / drain electrode material on the interlayer insulating film A photoresist is formed on the electrode material, the source / drain electrode material is etched by using the photoresist as an etching mask, the photoresist is ashed, and the film thickness of the source / drain electrode material is adjusted by using the photoresist as an etching mask. The process of forming the source / drain electrodes by halfway etching, the semiconductor film material, the gate insulating film material, and the gate electrode. A step of sequentially forming a material and a photoresist on the gate electrode material, and a step of etching the semiconductor film material, the gate insulating film material, and the gate electrode material using the photoresist as an etching mask to form the semiconductor film and the gate insulating material. And a step of forming a film and a gate electrode.

The method of manufacturing the thin film transistor of the present invention is
A material for the light-shielding film and the lower capacitor electrode is formed on the substrate, a photoresist is formed on the material for the light-shielding film and lower capacitor electrode, and the light-shielding film and the lower capacitor electrode are formed by using the photoresist as an etching mask. The material is etched to form a light shielding film and a capacitor lower electrode, an oxide film is formed on the capacitor lower electrode, an interlayer insulating film is formed, and a source / drain electrode material and an intermediate film are formed on the interlayer insulating film. Forming a photoresist on the intermediate film, etching the intermediate film and the source / drain electrode material using the photoresist as an etching mask, ashing the photoresist, and using the photoresist as an etching mask, the intermediate film and the source A step of forming a source / drain electrode by etching to the middle of the film thickness of the drain electrode material; a semiconductor film material and a gate insulating film material; A step of sequentially forming a gate electrode material and forming a photoresist on the gate electrode material, and a semiconductor film material, a gate insulating film material, and a gate electrode material are etched by using the photoresist as an etching mask. And a step of forming a gate insulating film and a gate electrode.

The method of manufacturing the thin film transistor of the present invention is
A material for the light-shielding film and the lower capacitor electrode is formed on the substrate, a photoresist is formed on the material for the light-shielding film and lower capacitor electrode, and the light-shielding film and the lower capacitor electrode are formed by using the photoresist as an etching mask. A step of etching the material to form a light-shielding film and a capacitor lower electrode, forming an interlayer insulating film, and forming a source / drain electrode material on the interlayer insulating film,
Forming a photoresist on the source / drain electrode material,
The photoresist is used as an etching mask to etch the source / drain electrode material to the middle of the film thickness, the photoresist is ashed, and the photoresist is used as an etching mask to etch the source / drain electrode material to form the source / drain electrode. And a step of sequentially forming a semiconductor film material, a gate insulating film material, and a gate electrode material, and forming a photoresist on the gate electrode material, and a semiconductor film material and a gate insulating film using the photoresist as an etching mask. And a step of etching the material and the gate electrode material to form a semiconductor film, a gate insulating film, and a gate electrode.

The method of manufacturing the thin film transistor of the present invention comprises:
A material for the light-shielding film and the lower capacitor electrode is formed on the substrate, a photoresist is formed on the material for the light-shielding film and lower capacitor electrode, and the light-shielding film and the lower capacitor electrode are formed by using the photoresist as an etching mask. A step of forming a light shielding film and a capacitor lower electrode by etching the material, forming an interlayer insulating film, forming a source / drain electrode material and an intermediate film on the interlayer insulating film, and forming a photoresist on the intermediate film, The photoresist is used as an etching mask to etch the intermediate film and the source / drain electrode material to the middle of the film thickness, the photoresist is ashed, and the photoresist is used as an etching mask to etch the source / drain electrode material and the source / drain. The step of forming the electrode, the semiconductor film material, the gate insulating film material, and the gate electrode material are sequentially formed, and the gate electrode Forming a semiconductor film, a gate insulating film and a gate electrode by etching a semiconductor film material, a gate insulating film material and a gate electrode material using the photoresist as an etching mask And having.

The method of manufacturing the thin film transistor of the present invention is
A material for the light-shielding film and the lower capacitor electrode is formed on the substrate, a photoresist is formed on the material for the light-shielding film and lower capacitor electrode, and the light-shielding film and the lower capacitor electrode are formed by using the photoresist as an etching mask. The step of etching the material to form a light-shielding film and a capacitor lower electrode, forming an oxide film on the capacitor lower electrode and forming an interlayer insulating film, and forming a source / drain electrode material on the interlayer insulating film A photoresist is formed on the electrode material, the photoresist is used as an etching mask to etch the source / drain electrode material to the middle of the film thickness, the photoresist is ashed, and the photoresist is used as an etching mask. The step of etching the material to form the source / drain electrode, the semiconductor film material, the gate insulating film material, and the gate electrode. A step of sequentially forming a material and a photoresist on the gate electrode material, and a step of etching the semiconductor film material, the gate insulating film material, and the gate electrode material using the photoresist as an etching mask to form the semiconductor film and the gate insulating material. And a step of forming a film and a gate electrode.

The method of manufacturing the thin film transistor of the present invention is
A material for the light-shielding film and the lower capacitor electrode is formed on the substrate, a photoresist is formed on the material for the light-shielding film and lower capacitor electrode, and the light-shielding film and the lower capacitor electrode are formed by using the photoresist as an etching mask. The material is etched to form a light shielding film and a capacitor lower electrode, an oxide film is formed on the capacitor lower electrode, an interlayer insulating film is formed, and a source / drain electrode material and an intermediate film are formed on the interlayer insulating film. , A photoresist is formed on the intermediate film, the photoresist is used as an etching mask to etch the intermediate film and the source / drain electrode material to the middle of the film thickness, the photoresist is ashed, and the photoresist is used as an etching mask. Etching the source / drain electrode material to form the source / drain electrode, the semiconductor film material, the gate insulating film material, and the gate electrode. A step of sequentially forming a material and a photoresist on the gate electrode material, and a step of etching the semiconductor film material, the gate insulating film material, and the gate electrode material using the photoresist as an etching mask to form the semiconductor film and the gate insulating material. And a step of forming a film and a gate electrode.

The method of manufacturing the thin film transistor of the present invention comprises:
A material for the light-shielding film and the lower capacitor electrode is formed on the substrate, a photoresist is formed on the material for the light-shielding film and lower capacitor electrode, and the light-shielding film and the lower capacitor electrode are formed by using the photoresist as an etching mask. A step of etching the material to form a light-shielding film and a capacitor lower electrode, forming an interlayer insulating film, and forming a source / drain electrode material on the interlayer insulating film,
Forming a photoresist on the source / drain electrode material,
The photoresist is used as an etching mask to etch the source / drain electrode material up to the middle of the film thickness, and the photoresist is heat-treated to soften it. Further, the photoresist is used as an etching mask to etch the source / drain electrode material and the source / drain. A step of forming electrodes,
A step of sequentially forming a semiconductor film material, a gate insulating film material, and a gate electrode material, and forming a photoresist on the gate electrode material; and a semiconductor film material, a gate insulating film material, and a gate electrode using the photoresist as an etching mask. And a step of forming a semiconductor film, a gate insulating film, and a gate electrode by etching a material.

The method of manufacturing the thin film transistor of the present invention comprises:
A material for the light-shielding film and the lower capacitor electrode is formed on the substrate, a photoresist is formed on the material for the light-shielding film and lower capacitor electrode, and the light-shielding film and the lower capacitor electrode are formed by using the photoresist as an etching mask. A step of etching the material to form a light-shielding film and a capacitor lower electrode, forming an interlayer insulating film, and forming a source / drain electrode material on the interlayer insulating film,
A first photoresist is formed on the source / drain electrode material, the source / drain electrode material is etched by using the photoresist as an etching mask, the first photoresist is removed, and the first photoresist is further formed on the source / drain electrode material.
Forming a second photoresist having a pattern size smaller than that of the photoresist, and using the second photoresist as an etching mask to etch the source / drain electrode material to the middle of the film thickness to form a source / drain electrode, A step of sequentially forming a semiconductor film material, a gate insulating film material, and a gate electrode material, and forming a photoresist on the gate electrode material; and a semiconductor film material, a gate insulating film material, and a gate electrode using the photoresist as an etching mask. And a step of forming a semiconductor film, a gate insulating film, and a gate electrode by etching a material.

The method of manufacturing the thin film transistor of the present invention is
A material for the light-shielding film and the lower capacitor electrode is formed on the substrate, a photoresist is formed on the material for the light-shielding film and lower capacitor electrode, and the light-shielding film and the lower capacitor electrode are formed by using the photoresist as an etching mask. A step of etching the material to form a light-shielding film and a capacitor lower electrode, forming an interlayer insulating film, and forming a source / drain electrode material on the interlayer insulating film,
A first photoresist is formed on the source / drain electrode material, the photoresist is used as an etching mask to etch the source / drain electrode material to the middle of the film thickness, and the first photoresist is removed. Forming a source / drain electrode by forming a second photoresist having a pattern size smaller than that of the first photoresist on the upper side, and etching the source / drain electrode material using the second photoresist as an etching mask; A step of sequentially forming a film material, a gate insulating film material, and a gate electrode material, and forming a photoresist on the gate electrode material; and a semiconductor film material, a gate insulating film material, and a gate electrode material using the photoresist as an etching mask And are etched to form a semiconductor film, a gate insulating film, and a gate electrode. And having a degree.

The method of manufacturing the thin film transistor of the present invention is
A material for the light-shielding film and the lower capacitor electrode is formed on the substrate, a photoresist is formed on the material for the light-shielding film and lower capacitor electrode, and the light-shielding film and the lower capacitor electrode are formed by using the photoresist as an etching mask. A step of etching the material to form a light-shielding film and a capacitor lower electrode, forming an interlayer insulating film, and forming a source / drain electrode material on the interlayer insulating film,
A first photoresist is formed on the source / drain electrode material, the first photoresist is used as an etching mask to etch the source / drain electrode material up to the middle of the film thickness, and the first photoresist is removed. A step of forming a second photoresist having a pattern size larger than that of the first photoresist on the drain electrode material, and etching the source / drain electrode material using the second photoresist as an etching mask to form a source / drain electrode. A step of sequentially forming a semiconductor film material, a gate insulating film material, and a gate electrode material, and forming a photoresist on the gate electrode material; and a semiconductor film material and a gate insulating film material using the photoresist as an etching mask. The gate electrode material is etched to form the semiconductor film, the gate insulating film, and the gate electrode. Characterized by a step of.

[0052]

In the thin film transistor of the present invention, a structure is employed in which the source / drain electrode is provided with a step and the cross-sectional shape is stepwise. When the step is formed on the source / drain electrode in this way, the step size of the semiconductor film formed on the source / drain electrode can be reduced.

Therefore, in the side surface region of the patterned source / drain electrode and the substrate, it is possible to mitigate the disorder of the crystallinity due to the different growth directions of the film to be the semiconductor film. Therefore, it is possible to reduce the characteristics of the thin film transistor, in particular, the deterioration of the threshold voltage and the mobility and the variation thereof.

Further, in the thin film transistor of the present invention in which the source / drain electrode is provided with a step, the step coverage of the film formed on the source / drain electrode is improved, the occurrence of disconnection in the step region of the source / drain electrode is suppressed, and the thin film transistor It is possible to prevent the occurrence of element defects.

[0055]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of a thin film transistor and its manufacturing method according to an embodiment of the present invention will be described below with reference to the drawings.
First, the structure of the thin film transistor according to the embodiment of the present invention will be described with reference to the sectional view of FIG. In the following description of the embodiments, an example in which a thin film transistor is provided on a substrate having an insulating property will be described.

As shown in FIG. 5, the source / drain electrodes 13 are provided on the substrate 11 made of glass having an insulating property.
The source / drain electrodes 13 are arranged so that a gap is provided therebetween, and this gap corresponds to the channel region of the thin film transistor.

A step is provided on the source / drain electrode 13, and the cross-sectional shape is stepwise. The size of the step provided on the source / drain electrode 13 is preferably about half the film thickness of the source / drain electrode 13. That is, a step having a depth dimension of about half the thickness of the source / drain electrode 13 is formed from the surface.

Source / drain electrode 13 having this step
The semiconductor film 15 is provided thereon, and the gate insulating film 17 is further provided on the semiconductor film 15. The semiconductor film 15 is made of a silicon film, and the semiconductor film 15 made of the silicon film becomes an active region of the thin film transistor. Furthermore, the gate electrode 19 is provided on the gate insulating film 17.

Thus, a thin film transistor having a structure of the metal of the gate electrode 19, the insulating film of the gate insulating film 17, and the semiconductor of the semiconductor film 15 is formed.

In the thin film transistor structure of the present invention, as shown in FIG. 5, the source / drain electrode 13 is provided with a step, and its cross-sectional shape is stepwise. When the step is provided on the source / drain electrode 13 in this manner, the step size of the semiconductor film 15 provided on the source / drain electrode 13 can be substantially reduced.

Therefore, in the side surface region of the patterned source / drain electrode 13 and the substrate 11, the crystallinity disorder caused by the different growth directions of the film to be the semiconductor film 15 can be alleviated. Therefore, it is possible to reduce the characteristics of the thin film transistor, in particular, the deterioration of the threshold voltage and the mobility and the variation thereof.

Furthermore, in the thin film transistor of the present invention in which the source / drain electrode 13 is provided with a step, the step coverage of the film provided on the source / drain electrode 13 is improved. As a result, in the step region of the source / drain electrode 13, the occurrence of disconnection of the coating film provided on the upper layer is prevented,
It is possible to suppress the occurrence of device defects in the thin film transistor.

Next, a manufacturing method for forming the structure of the thin film transistor shown in FIG. 5 will be described with reference to the sectional views of FIGS.

First, as shown in FIG. 1, a transparent conductive film made of an indium tin oxide (ITO) film is formed as a material of the source / drain electrode 13 on the entire surface of a substrate 11 made of insulating glass. This indium tin oxide film is formed with a film thickness of 200 nm using a sputtering apparatus.

Then, a photoresist 2 which is a photosensitive material is formed on the entire surface of the indium tin oxide film by spin coating.
7 is formed. Then, an exposure process and a development process are performed using a predetermined photomask to pattern the photoresist 27 into the pattern shape of the source / drain electrode 13.

Thereafter, using the patterned photoresist 27 as an etching mask, the indium tin oxide film is patterned by the reactive ion etching method to form the source / drain electrodes 13.

The reactive ion etching treatment of this indium tin oxide film is carried out using a mixed gas of methane (CH ₄ ), carbon tetrachloride (CCl ₄ ) and hydrogen (H ₂ ) as a reaction gas. Alternatively, by a wet etching method using an aqueous solution of ferric chloride (FeCl ₃ ) and hydrochloric acid (HCl),
The source / drain electrode 13 material can also be etched.

Next, as shown in FIG. 2, the photoresist 27 on the source / drain electrodes 13 is subjected to an ashing process to reduce the pattern size of the photoresist 27.
This photoresist 27 is
The size is reduced from the initial size by 0.1 μm to 0.2 μm.

By controlling the time of the ashing process for reducing the pattern size, the pattern size of the photoresist 27 is reduced by 0.1 μm to 0.2 μm, which is the size described above.

This ashing treatment is performed at 100 sccm to within a dry etching apparatus which is evacuated by the evacuation means.
Oxygen (O ₂ ) was introduced at a flow rate of 1000 sccm, and the pressure inside the apparatus was set to 100 mTorr to 300 mTorr.
1 high frequency power of 13.56MHz oscillation frequency
It is performed by using plasma generated by applying from 00W to 500W.

The dimension for reducing the pattern dimension of the photoresist 27 by this ashing process is controlled by the ashing time.

Next, as shown in FIG. 3, the source / drain electrode 13 exposed from the photoresist is etched by using the photoresist 27 having the reduced pattern size as an etching mask. Form a step.

The etching process for forming the step on the source / drain electrode 13 is performed by the above-mentioned reaction gas such as methane (CH ₄ ), carbon tetrachloride (CCl ₄ ), and hydrogen (H).
_The reactive ion etching method using a mixed gas with ₂ ) may be used.

Then, the photoresist 27 used as the etching mask for patterning the source / drain electrodes 13 is removed. To remove the photoresist 27, a mixed solution of sulfuric acid (H ₂ SO ₄ ) and hydrogen peroxide (H ₂ O ₂ ) is used.

Next, as shown in FIG. 4, a material of the semiconductor film 15 made of non-single crystal silicon is formed on the entire surface of the substrate 11 by 150.
It is formed with a thickness of nm. The material of the semiconductor film 15 is formed by using monosilane (SiH ₄ ) as a reaction gas and using a plasma chemical vapor deposition apparatus.

After that, a gate insulating film 17 made of a silicon oxide (SiO ₂ ) film is formed on the entire surface of the material of the semiconductor film 15.
It is formed with a film thickness of 00 nm. This gate insulating film 17 is
Monosilane (SiH ₄ ) and oxygen (O ₂ ) as reaction gases
And by using a plasma enhanced chemical vapor deposition apparatus.

After that, a gate electrode 19 material made of a molybdenum (Mo) film is formed on the entire surface of the material of the gate insulating film 17 by 2 steps.
It is formed with a film thickness of 00 nm. This molybdenum film is formed using a sputtering device.

Then, a photoresist 27, which is a photosensitive material, is formed on the entire surface of the material of the gate electrode 19 by spin coating.
To form Then, an exposure process and a development process are performed using a predetermined photomask to pattern the photoresist 27 into the pattern shape of the gate electrode 19.

Next, as shown in FIG. 5, using the patterned photoresist 27 as an etching mask, the molybdenum film is patterned by the wet etching method to form the gate electrode 19.

The gate electrode 19 made of this molybdenum film
Wet etching treatment of phosphoric acid (H ₃ PO ₄ ), nitric acid (HNO ₃ ), acetic acid (CH ₃ CO ₄ )
OH).

Then, using the photoresist 27 as an etching mask, the gate insulating film 17 material and the semiconductor film 15 are formed.
The material and the material are patterned by the reactive ion etching method to form the gate insulating film 17 and the semiconductor film 15.

The material of the gate insulating film 17 and the semiconductor film 15
The reactive ion etching treatment with the material is performed using a mixed gas of sulfur hexafluoride (SF ₆ ) and oxygen (O ₂ ) as an etching gas.

As described above, in the method of manufacturing a thin film transistor according to the present invention, the photoresist 27 formed on the material of the source / drain electrode 13 is subjected to ashing treatment to reduce the pattern size, and the source / drain electrode 13 having a step is formed. ing.

Therefore, in the present invention, the disorder of the crystallinity due to the different growth directions of the film to be the semiconductor film 15 can be alleviated, and the deterioration or variation in the threshold voltage and mobility of the thin film transistor can be prevented. Can be made smaller. Further, the step coverage of the film provided on the source / drain electrode 13 is improved, the occurrence of disconnection in the step region of the source / drain electrode 13 can be prevented, and the occurrence of element defects in the thin film transistor can be suppressed.

Next, a method of manufacturing a thin film transistor in an embodiment different from the above description for forming a step in the source / drain electrode 13 will be described with reference to FIGS.
This will be described with reference to FIG.

First, as shown in FIG. 6, a transparent conductive film made of an indium tin oxide (ITO) film is formed as a source / drain electrode 13 material on the entire surface of a substrate 11 made of insulating glass. The transparent conductive film made of this indium tin oxide film is formed with a film thickness of 200 nm by using a sputtering apparatus.

Then, a photoresist 2 which is a photosensitive material is formed on the entire surface of the indium tin oxide film by spin coating.
7 is formed. Then, an exposure process and a development process are performed using a predetermined photomask to pattern the photoresist 27 into the pattern shape of the source / drain electrode 13.

Then, using the patterned photoresist 27 as an etching mask, the indium tin oxide film is etched by 100 nm, which is half the film thickness, by the reactive ion etching method. Here, the dimension obtained by etching the material of the source / drain electrode 13 corresponds to the step.

The reactive ion etching treatment of this indium tin oxide film is carried out using a mixed gas of methane (CH ₄ ), carbon tetrachloride (CCl ₄ ) and hydrogen (H ₂ ) as a reaction gas.

Next, as shown in FIG. 7, the photoresist 27 on the source / drain electrode 13 material is subjected to an ashing process to reduce the pattern size of the photoresist 27. By this ashing process, the photoresist 2
7 is 0.1 μm to 0.2 from the initial pattern size
It becomes smaller by μm. By controlling the ashing processing time for reducing the pattern size, the photoresist 27 having a small pattern size is formed.

This ashing treatment is performed at 100 sccm to within a dry etching apparatus which is evacuated by the evacuation means.
Oxygen (O ₂ ) was introduced at a flow rate of 1000 sccm, and the pressure inside the apparatus was set to 100 mTorr to 300 mTorr.
1 high frequency power of 13.56MHz oscillation frequency
It is performed by using plasma generated by applying from 00W to 500W.

The dimension for reducing the pattern dimension of the photoresist 27 by this ashing process is controlled by the ashing time.

Then, as shown in FIG. 8, using the photoresist 27 having the reduced pattern size as an etching mask, the material of the source / drain electrode 13 exposed from the photoresist is etched to form a source having a step. The drain electrode 13 is formed.

The etching process for forming the step on the source / drain electrode 13 is performed by the above-mentioned reaction gas such as methane (CH ₄ ), carbon tetrachloride (CCl ₄ ), and hydrogen (H).
_The reactive ion etching method using a mixed gas with ₂ ) may be used.

In the reactive ion etching process of etching the material of the source / drain electrode 13 to form the source / drain electrode 13 having steps, the ions to be etched are substantially perpendicular to the surface of the substrate 11 Incident on material.

As a result, the source / drain electrode 13 material shown in FIG. 7 can be patterned while maintaining the pattern shape in which half the film thickness is etched, and the source / drain electrode 13 can be patterned. It is possible to form a step having half the film thickness.

After that, the photoresist 27 used as an etching mask for patterning the source / drain electrodes 13 is removed. To remove the photoresist 27, a mixed solution of sulfuric acid (H ₂ SO ₄ ) and hydrogen peroxide (H ₂ O ₂ ) is used.

Next, as shown in FIG. 4, the material of the semiconductor film 15 made of a non-single crystal silicon film is formed on the entire surface of the substrate 11 by 15
It is formed with a thickness of 0 nm. The material of the semiconductor film 15 is formed by using monosilane (SiH ₄ ) as a reaction gas and using a plasma chemical vapor deposition apparatus.

After that, a gate insulating film 17 made of a silicon oxide (SiO ₂ ) film is formed on the entire surface of the material of the semiconductor film 15.
It is formed with a film thickness of 00 nm. This gate insulating film 17 is
Monosilane (SiH ₄ ) and oxygen (O ₂ ) as reaction gases
It is formed by a plasma chemical vapor deposition apparatus using and.

After that, a gate electrode 19 material made of a molybdenum (Mo) film is formed on the entire surface of the gate insulating film 17 material.
It is formed with a film thickness of 200 nm using a sputtering apparatus.

Then, a photoresist 27, which is a photosensitive material, is formed on the entire surface of the material of the gate electrode 19 by spin coating.
To form Then, an exposure process and a development process are performed using a predetermined photomask to pattern the photoresist 27 into the pattern shape of the gate electrode 19.

Then, as shown in FIG. 5, the molybdenum film is patterned by wet etching using the patterned photoresist 27 as an etching mask to form the gate electrode 19.

The gate electrode 19 made of this molybdenum film
Wet etching treatment of phosphoric acid (H ₃ PO ₄ ), nitric acid (HNO ₃ ), acetic acid (CH ₃ CO ₄ )
OH).

After that, by using the photoresist 27 as an etching mask, the material of the gate insulating film 17 and the semiconductor film 15 are formed.
The material and the material are patterned by the reactive ion etching method to form the gate insulating film 17 and the semiconductor film 15.

The material of the gate insulating film 17 and the semiconductor film 15
The reactive ion etching treatment with the material is performed using a mixed gas of sulfur hexafluoride (SF ₆ ) and oxygen (O ₂ ) as an etching gas.

As described above, in the method of manufacturing a thin film transistor of the present invention, the photoresist 27 formed on the material of the source / drain electrode 13 is subjected to ashing treatment to reduce its pattern size, and the source / drain electrode 13 having a step is formed. ing.

Therefore, in the present invention, the disorder of the crystallinity due to the different growth directions of the film to be the semiconductor film 15 can be alleviated, and the deterioration or variation in the threshold voltage and mobility of the thin film transistor can be prevented. Can be made smaller. Further, the step coverage of the film provided on the source / drain electrode 13 is improved, the occurrence of disconnection in the step region of the source / drain electrode 13 can be prevented, and the occurrence of element defects in the thin film transistor can be suppressed.

Next, a method of manufacturing a thin film transistor in an embodiment different from the above description for forming a step in the source / drain electrode 13 will be described with reference to FIGS. 9 to 11, 4 and 5.

First, as shown in FIG. 9, a transparent conductive film made of an indium tin oxide (ITO) film is formed as the material of the source / drain electrode 13 on the entire surface of the substrate 11 made of insulating glass. The transparent conductive film made of this indium tin oxide film is formed with a film thickness of 200 nm by using a sputtering apparatus.

Then, a photoresist 2 which is a photosensitive material is formed on the entire surface of the indium tin oxide film by a spin coating method.
7 is formed. Then, an exposure process and a development process are performed using a predetermined photomask to pattern the photoresist 27 into the pattern shape of the source / drain electrode 13.

Then, using the patterned photoresist 27 as an etching mask, the indium tin oxide film is etched by 100 nm, which is half the film thickness, by the reactive ion etching method. Here, the dimension obtained by etching the material of the source / drain electrode 13 corresponds to the step.

The reactive ion etching treatment of this indium tin oxide film is carried out using a mixed gas of methane (CH ₄ ), carbon tetrachloride (CCl ₄ ) and hydrogen (H ₂ ) as a reaction gas.

Next, as shown in FIG. 10, the photoresist 27 on the material of the source / drain electrode 13 is heat-treated to soften the photoresist 27 so that the photoresist 27 hangs down on the etched material of the source / drain electrode 13. . The heat treatment at this time is performed at a temperature at which the photoresist 27 is softened without being carbonized.

The heat treatment at this time is performed by the photoresist 27.
Is 180 ° C to 200, which is the temperature at which the material softens without carbonization
Perform at ° C. By this softening treatment of the photoresist 27, the photoresist 27 has a pattern size of 0.
It increases from 1 μm to 0.2 μm.

Next, as shown in FIG. 11, the softened photoresist 27 having a large pattern size is used as an etching mask to etch the material of the source / drain electrode 13 exposed from the photoresist, to thereby remove the source / drain electrode. A step is formed at 13.

The etching process for forming the step on the source / drain electrode 13 is performed by the above-mentioned reaction gas such as methane (CH ₄ ), carbon tetrachloride (CCl ₄ ), hydrogen (H).
_The reactive ion etching method using a mixed gas with ₂ ) may be used. Alternatively, the source / drain electrode 13 material having a step can be formed by etching the material of the source / drain electrode 13 by a wet etching method using an aqueous solution of ferric chloride (FeCl ₃ ) and hydrochloric acid (HCl).

After that, the photoresist 27 used as the etching mask for patterning the source / drain electrodes 13 is removed. To remove the photoresist 27, a mixed solution of sulfuric acid (H ₂ SO ₄ ) and hydrogen peroxide (H ₂ O ₂ ) is used. Alternatively, oxygen (O
Photoresist 2 by ashing process using ₂ )
7 may be removed.

Next, as shown in FIG. 4, the material of the semiconductor film 15 made of a non-single crystal silicon film is formed on the entire surface of the substrate 11 by 15
It is formed with a thickness of 0 nm. The material of the semiconductor film 15 is formed by using monosilane (SiH ₄ ) as a reaction gas and using a plasma chemical vapor deposition apparatus.

After that, a gate insulating film 17 made of a silicon oxide (SiO ₂ ) film is formed on the entire surface of the material of the semiconductor film 15.
It is formed with a film thickness of 00 nm. This gate insulating film 17 is
Monosilane (SiH ₄ ) and oxygen (O ₂ ) as reaction gases
It is formed by a plasma chemical vapor deposition apparatus using and.

Then, a gate electrode 19 material made of a molybdenum (Mo) film is formed on the entire surface of the gate insulating film 17 material.
It is formed with a film thickness of 200 nm using a sputtering apparatus.

Then, a photoresist 27, which is a photosensitive material, is formed on the entire surface of the material of the gate electrode 19 by spin coating.
To form Then, an exposure process and a development process are performed using a predetermined photomask to pattern the photoresist 27 into the pattern shape of the gate electrode 19.

Next, as shown in FIG. 5, using the patterned photoresist 27 as an etching mask, the molybdenum film is patterned by the wet etching method to form the gate electrode 19.

The gate electrode 19 made of this molybdenum film
Wet etching treatment of phosphoric acid (H ₃ PO ₄ ), nitric acid (HNO ₃ ), acetic acid (CH ₃ CO ₄ )
OH).

Then, using the photoresist 27 as an etching mask, the gate insulating film 17 material and the semiconductor film 15 are formed.
The material and the material are patterned by the reactive ion etching method to form the gate insulating film 17 and the semiconductor film 15.

The material of the gate insulating film 17 and the semiconductor film 15
The reactive ion etching treatment with the material is performed using a mixed gas of sulfur hexafluoride (SF ₆ ) and oxygen (O ₂ ) as an etching gas.

As described above, in the method of manufacturing a thin film transistor according to the present invention, the photoresist 27 formed on the material of the source / drain electrode 13 is softened to increase its pattern size, and the source / drain electrode 13 having a step is formed. There is.

Therefore, in the present invention, the disorder of the crystallinity due to the different growth directions of the film to be the semiconductor film 15 can be alleviated, and the deterioration or variation in the threshold voltage and mobility of the thin film transistor can be prevented. Can be made smaller. Furthermore, the step coverage of the film provided on the source / drain electrode 13 is improved, the occurrence of disconnection in the step region of the source / drain electrode 13 can be suppressed, and the occurrence of element defects in the thin film transistor can be prevented.

Next, a method of manufacturing a thin film transistor in an embodiment different from the above description for forming a step in the source / drain electrode 13 will be described with reference to FIGS. 12 to 14, 4 and 5.

First, as shown in FIG. 12, a transparent conductive film made of an indium tin oxide film is formed as a source / drain electrode 13 material on the entire surface of a substrate 11 made of insulating glass. This indium tin oxide film is
It is formed with a film thickness of 200 nm using a sputtering apparatus.

Then, a first photoresist 29, which is a photosensitive material, is formed on the entire surface of the indium tin oxide film by spin coating. After that, an exposure process and a development process are performed using a predetermined photomask to form the first photoresist 29 in the pattern shape of the source / drain electrode 13.

Then, using the patterned first photoresist 29 as an etching mask, the indium tin oxide film is patterned by the reactive ion etching method to form the source / drain electrodes 13.

The reactive ion etching treatment of this indium tin oxide film is carried out using a mixed gas of methane (CH ₄ ), carbon tetrachloride (CCl ₄ ) and hydrogen (H ₂ ) as a reaction gas. Alternatively, by a wet etching method using an aqueous solution of ferric chloride (FeCl ₃ ) and hydrochloric acid (HCl),
The source / drain electrode 13 can also be formed by etching the material of the source / drain electrode 13.

After that, the first photoresist 29 used as an etching mask for patterning the source / drain electrodes 13 is removed. The removal of the first photoresist 29 is performed using a mixed solution of sulfuric acid (H ₂ SO ₄ ) and hydrogen peroxide (H ₂ O ₂ ).

Next, as shown in FIG. 13, a second photoresist 31 which is a photosensitive material is formed on the entire surface of the substrate 11 by spin coating. After that, an exposure process and a development process are performed using a predetermined photomask to form the second photoresist 31 in the pattern shape of the source / drain electrode 13.

At this time, the pattern dimension of the second photoresist 31 is smaller than that of the first photoresist 29 by 0.1 μm to 0.2 μm.

Next, as shown in FIG. 14, the source / drain electrodes 13 exposed from the second photoresist 31 are etched by using the second photoresist 31 having a small pattern size as an etching mask. Thus, a step is formed on the source / drain electrode 13.

The etching process for forming the step on the source / drain electrode 13 is performed by the above-mentioned reaction gas such as methane (CH ₄ ), carbon tetrachloride (CCl ₄ ), and hydrogen (H).
_The reactive ion etching method using a mixed gas with ₂ ) may be used.

Then, the photoresist 27 used as the etching mask for patterning the source / drain electrodes 13 is removed. To remove the photoresist 27, a mixed solution of sulfuric acid (H ₂ SO ₄ ) and hydrogen peroxide (H ₂ O ₂ ) is used.

Next, as shown in FIG. 4, the material of the semiconductor film 15 made of a non-single-crystal silicon film is formed on the entire surface of the substrate 11 by 15
It is formed with a thickness of 0 nm. The material of the semiconductor film 15 is formed by a plasma chemical vapor deposition apparatus using monosilane (SiH ₄ ) as a reaction gas.

Then, a gate insulating film 17 made of a silicon oxide (SiO ₂ ) film is formed on the entire surface of the material of the semiconductor film 15.
It is formed with a film thickness of 00 nm. This gate insulating film 17 is
Monosilane (SiH ₄ ) and oxygen (O ₂ ) as reaction gases
And by using a plasma enhanced chemical vapor deposition apparatus.

Thereafter, a material for the gate electrode 19 made of a molybdenum (Mo) film is formed on the entire surface of the material for the gate insulating film 17.
It is formed with a film thickness of 200 nm using a sputtering apparatus.

Then, the photoresist 27, which is a photosensitive material, is formed on the entire surface of the material of the gate electrode 19 by spin coating.
To form Then, an exposure process and a development process are performed using a predetermined photomask to pattern the photoresist 27 into the pattern shape of the gate electrode 19.

Next, as shown in FIG. 5, using the patterned photoresist 27 as an etching mask, the molybdenum film is patterned by the wet etching method to form the gate electrode 19.

The gate electrode 19 made of this molybdenum film
Wet etching treatment of phosphoric acid (H ₃ PO ₄ ), nitric acid (HNO ₃ ), acetic acid (CH ₃ CO ₄ )
OH).

After that, using the photoresist 27 as an etching mask, the material of the gate insulating film 17 and the semiconductor film 15 are formed.
The material and the material are patterned by the reactive ion etching method to form the gate insulating film 17 and the semiconductor film 15.

The material of the gate insulating film 17 and the semiconductor film 15
The reactive ion etching treatment with the material is performed using a mixed gas of sulfur hexafluoride (SF ₆ ) and oxygen (O ₂ ) as an etching gas.

As described above, in the method of manufacturing a thin film transistor according to the present invention as described above, the source / drain electrode 1
The source / drain electrodes 13 having steps are formed due to the pattern size difference between the first photoresist 29 and the second photoresist 31 formed on the three materials.

Therefore, in the present invention, the disorder of the crystallinity due to the different growth directions of the film to be the semiconductor film 15 can be alleviated, and the threshold voltage and the mobility of the thin film transistor and the variation thereof can be prevented. Can be made smaller.

Furthermore, the step coverage of the film provided on the source / drain electrode 13 is improved, the occurrence of disconnection in the step region of the source / drain electrode 13 can be suppressed, and the element defect of the thin film transistor can be prevented.

Next, a method of manufacturing a thin film transistor in an embodiment different from the above description for forming a step in the source / drain electrode 13 will be described with reference to FIGS. 15 to 17, FIG. 4 and FIG.

First, as shown in FIG. 15, a transparent conductive film made of an indium tin oxide film is formed as a material of the source / drain electrode 13 on the entire surface of the substrate 11 made of insulating glass. This indium tin oxide film is
It is formed with a film thickness of 200 nm using a sputtering apparatus.

After that, a first photoresist 29 which is a photosensitive material is formed on the entire surface of the indium tin oxide film by spin coating. After that, an exposure process and a development process are performed using a predetermined photomask to form the first photoresist 29 in the pattern shape of the source / drain electrode 13.

Then, using the patterned first photoresist 29 as an etching mask, the indium tin oxide film is etched by 100 nm, which is half the film thickness, by the reactive ion etching method. Here, the dimension obtained by etching the material of the source / drain electrode 13 corresponds to the step.

The reactive ion etching treatment of this indium tin oxide film is performed using a mixed gas of methane (CH ₄ ), carbon tetrachloride (CCl ₄ ) and hydrogen (H ₂ ) as a reaction gas.

After that, the first photoresist 29 used as an etching mask for patterning the source / drain electrodes 13 is removed. The removal of the first photoresist 29 is performed using a mixed solution of sulfuric acid (H ₂ SO ₄ ) and hydrogen peroxide (H ₂ O ₂ ).

Then, as shown in FIG. 16, a second photoresist 31 which is a photosensitive material is formed on the entire surface of the substrate 11 by spin coating. After that, an exposure process and a development process are performed using a predetermined photomask to form the second photoresist 31 in the pattern shape of the source / drain electrode 13.

At this time, the pattern dimension of the second photoresist 31 is smaller than that of the first photoresist 29 by 0.1 μm to 0.2 μm.

Next, as shown in FIG. 17, the source / drain electrodes 13 exposed from the second photoresist 31 are etched by using the second photoresist 31 having a small pattern size as an etching mask. Thus, a step is formed on the source / drain electrode 13.

The etching process for forming the step on the source / drain electrode 13 is performed by the above-described reaction gas such as methane (CH ₄ ), carbon tetrachloride (CCl ₄ ), hydrogen (H).
_The reactive ion etching method using a mixed gas with ₂ ) may be used.

In the reactive ion etching process for forming the source / drain electrode 13 having a step by etching the material of the source / drain electrode 13, the ions to be etched are substantially perpendicular to the surface of the substrate 11. Incident on material.

As a result, the source / drain electrode 13 material shown in FIG. 16 can be patterned while maintaining the pattern shape in which half the film thickness is etched, and the source / drain electrode 13 material can be patterned.
It is possible to form a step having half the film thickness.

After that, the second photoresist 31 used as an etching mask for patterning the source / drain electrodes 13 is removed. The removal of the second photoresist 31 is performed using a mixed solution of sulfuric acid (H ₂ SO ₄ ) and hydrogen peroxide (H ₂ O ₂ ).

Next, as shown in FIG. 4, the material of the semiconductor film 15 made of a non-single-crystal silicon film is formed on the entire surface of the substrate 11 by 15
It is formed with a thickness of 0 nm. The material of the semiconductor film 15 is formed by a plasma chemical vapor deposition apparatus using monosilane (SiH ₄ ) as a reaction gas.

After that, a gate insulating film 17 made of a silicon oxide (SiO ₂ ) film is formed on the entire surface of the material of the semiconductor film 15.
It is formed with a film thickness of 00 nm. This gate insulating film 17 is
Monosilane (SiH ₄ ) and oxygen (O ₂ ) as reaction gases
And by using a plasma enhanced chemical vapor deposition apparatus.

Then, a gate electrode 19 material made of a molybdenum (Mo) film is formed on the entire surface of the gate insulating film 17 material.
It is formed with a film thickness of 200 nm using a sputtering apparatus.

Then, a photoresist 27, which is a photosensitive material, is formed on the entire surface of the material of the gate electrode 19 by spin coating.
To form Then, an exposure process and a development process are performed using a predetermined photomask to pattern the photoresist 27 into the pattern shape of the gate electrode 19.

Next, as shown in FIG. 5, using the patterned photoresist 27 as an etching mask, the molybdenum film is patterned by the wet etching method to form the gate electrode 19.

The gate electrode 19 made of this molybdenum film
Wet etching treatment of phosphoric acid (H ₃ PO ₄ ), nitric acid (HNO ₃ ), acetic acid (CH ₃ CO ₄ )
OH).

After that, using the photoresist 27 as an etching mask, the material of the gate insulating film 17 and the semiconductor film 15 are formed.
The material and the material are patterned by the reactive ion etching method to form the gate insulating film 17 and the semiconductor film 15.

The material of the gate insulating film 17 and the semiconductor film 15
The reactive ion etching treatment with the material is performed using a mixed gas of sulfur hexafluoride (SF ₆ ) and oxygen (O ₂ ) as an etching gas.

As described above, in the method of manufacturing a thin film transistor according to the present invention described above, the source / drain electrode 1
The source / drain electrodes 13 having steps are formed due to the pattern size difference between the first photoresist 29 and the second photoresist 31 formed on the three materials.

Therefore, according to the present invention, it is possible to mitigate the disorder of the crystallinity due to the difference in the growth direction of the film to be the semiconductor film 15, and to prevent the deterioration of the threshold voltage and the mobility of the thin film transistor and the variation thereof. Can be made smaller. Further, the step coverage of the film provided on the source / drain electrode 13 is improved, the occurrence of disconnection in the step region of the source / drain electrode 13 can be prevented, and the occurrence of element defects in the thin film transistor can be suppressed.

Next, a method of manufacturing a thin film transistor in an embodiment different from the above description for forming a step in the source / drain electrode 13 will be described with reference to FIGS. 18 to 20, FIG. 4 and FIG.

First, as shown in FIG. 18, a transparent conductive film made of an indium tin oxide film is formed as a source / drain electrode 13 material on the entire surface of a substrate 11 made of insulating glass. This indium tin oxide film is
It is formed with a film thickness of 200 nm using a sputtering apparatus.

After that, the first photoresist 29, which is a photosensitive material, is formed on the entire surface of the indium tin oxide film by spin coating. After that, an exposure process and a development process are performed using a predetermined photomask to form the first photoresist 29 in the pattern shape of the source / drain electrode 13.

Thereafter, using the patterned first photoresist 29 as an etching mask, the indium tin oxide film is etched by 100 nm, which is half the film thickness, by the reactive ion etching method. Here, the dimension obtained by etching the material of the source / drain electrode 13 corresponds to the step.

The reactive ion etching treatment of this indium tin oxide film is carried out using a mixed gas of methane (CH ₄ ), carbon tetrachloride (CCl ₄ ) and hydrogen (H ₂ ) as a reaction gas.

Then, the first photoresist 29 used as the etching mask for patterning the source / drain electrodes 13 is removed. The removal of the first photoresist 29 is performed using a mixed solution of sulfuric acid (H ₂ SO ₄ ) and hydrogen peroxide (H ₂ O ₂ ).

Next, as shown in FIG. 19, a second photoresist 31 which is a photosensitive material is formed on the entire surface of the substrate 11 by spin coating. After that, an exposure process and a development process are performed using a predetermined photomask to form the second photoresist 31 in the pattern shape of the source / drain electrode 13.

At this time, the pattern dimension of the second photoresist 31 is larger than that of the first photoresist 29 by 0.1 μm to 0.2 μm.

Then, as shown in FIG. 20, the source / drain electrodes 13 exposed from the second photoresist 31 are etched by using the second photoresist 31 having a small pattern size as an etching mask. Thus, a step is formed on the source / drain electrode 13.

The etching process for forming the step on the source / drain electrode 13 is performed by the above-mentioned reaction gas such as methane (CH ₄ ), carbon tetrachloride (CCl ₄ ), hydrogen (H).
_The reactive ion etching method using a mixed gas with ₂ ) may be used. Alternatively, the source / drain electrode 13 can be formed by etching the material of the source / drain electrode 13 by a wet etching method using an aqueous solution of ferric chloride (FeCl ₃ ) and hydrochloric acid (HCl).

After that, the second photoresist 31 used as an etching mask for patterning the source / drain electrodes 13 is removed. The removal of the second photoresist 31 is performed using a mixed solution of sulfuric acid (H ₂ SO ₄ ) and hydrogen peroxide (H ₂ O ₂ ).

Next, as shown in FIG. 4, the material of the semiconductor film 15 made of a non-single crystal silicon film is formed on the entire surface of the substrate 11 by 15
It is formed with a thickness of 0 nm. The material of the semiconductor film 15 is formed by a plasma chemical vapor deposition apparatus using monosilane (SiH ₄ ) as a reaction gas.

After that, a gate insulating film 17 made of a silicon oxide (SiO ₂ ) film is formed on the entire surface of the material of the semiconductor film 15 by one step.
It is formed with a film thickness of 00 nm. This gate insulating film 17 is
Monosilane (SiH ₄ ) and oxygen (O ₂ ) as reaction gases
It is formed by a plasma chemical vapor deposition apparatus using and.

After that, a gate electrode 19 material made of a molybdenum (Mo) film is formed on the entire surface of the gate insulating film 17 material.
It is formed with a film thickness of 200 nm using a sputtering apparatus.

Then, a photoresist 2 which is a photosensitive material is formed on the entire surface of the material of the gate electrode 19 by spin coating.
7 is formed. Then, an exposure process and a development process are performed using a predetermined photomask to pattern the photoresist 27 into the pattern shape of the gate electrode 19.

Next, as shown in FIG. 5, using the patterned photoresist 27 as an etching mask, the molybdenum film is patterned by the wet etching method to form the gate electrode 19.

The gate electrode 19 made of this molybdenum film
Wet etching treatment of phosphoric acid (H ₃ PO ₄ ), nitric acid (HNO ₃ ), acetic acid (CH ₃ CO ₄ )
OH).

After that, by using the photoresist 27 as an etching mask, the material of the gate insulating film 17 and the semiconductor film 15 are formed.
The material and the material are patterned by the reactive ion etching method to form the gate insulating film 17 and the semiconductor film 15.

This gate insulating film 17 material and semiconductor film 15
The reactive ion etching treatment with the material is performed using a mixed gas of sulfur hexafluoride (SF ₆ ) and oxygen (O ₂ ) as an etching gas.

As described above, in the method of manufacturing a thin film transistor of the present invention described above, the source / drain electrode 1
The source / drain electrodes 13 having steps are formed due to the pattern size difference between the first photoresist 29 and the second photoresist 31 formed on the three materials.

Therefore, according to the present invention, the disorder of crystallinity due to the different growth directions of the film to be the semiconductor film 15 can be alleviated, and the deterioration or variation in the threshold voltage and mobility of the thin film transistor can be prevented. Can be made smaller. Further, the step coverage of the film provided on the source / drain electrode 13 is improved, the occurrence of disconnection in the step region of the source / drain electrode 13 can be prevented, and the occurrence of element defects in the thin film transistor can be suppressed.

Next, the structure of the thin film transistor and the manufacturing method thereof in the embodiment different from the above description will be described.
First, the structure of the thin film transistor according to the embodiment of the present invention will be described with reference to the sectional view of FIG.

As shown in FIG. 23, the source / drain electrodes 13 are provided on the substrate 11 having an insulating property and made of glass so that a gap is provided therebetween. This gap corresponds to the channel region of the thin film transistor.

A step is provided on the source / drain electrode 13, and the cross-sectional shape is stepwise. The size of the step provided on the source / drain electrode 13 is preferably about half the film thickness of the source / drain electrode 13. That is, a step having a depth dimension of about half the thickness of the source / drain electrode 13 is formed from the surface.

Source / drain electrode 13 having this step
An intermediate film 37 is provided on top. Further, the semiconductor film 15 is provided on the intermediate film 37, and the gate insulating film 17 is further provided on the semiconductor film 15. Furthermore, this gate insulating film 1
A gate electrode 19 is provided on 7.

Here, the outer peripheral portion of the intermediate film 37 is the semiconductor film 1
The same pattern shape as the outer peripheral portion of No. 5 is used. Then, the semiconductor film 15 made of a silicon film becomes an active region of the thin film transistor.

Thus, a thin film transistor having a structure of the metal of the gate electrode 19, the insulating film of the gate insulating film 17, and the semiconductor of the semiconductor film 15 is formed.

In the thin film transistor structure of the present invention, as shown in FIG. 23, the source / drain electrode 13 is provided with a step and the cross-sectional shape is stepwise. When the step is provided on the source / drain electrode 13 in this manner, the step size of the semiconductor film 15 provided on the source / drain electrode 13 can be substantially reduced.

Therefore, in the side surface region of the patterned source / drain electrode 13 and the substrate 11, the disorder of crystallinity due to the different growth directions of the film to be the semiconductor film 15 can be alleviated. Therefore, it is possible to reduce the characteristics of the thin film transistor, in particular, the deterioration of the threshold voltage and the mobility and the variation thereof.

Further, in the thin film transistor of the present invention in which the source / drain electrode 13 is provided with a step, the step coverage of the film provided on the source / drain electrode 13 is improved. As a result, in the step region of the source / drain electrode 13, the occurrence of disconnection of the coating film provided on the upper layer is prevented,
It is possible to suppress the occurrence of device defects in the thin film transistor.

Further, in the thin film transistor shown in FIG. 23, by providing the intermediate film 37, mutual reaction between the source / drain electrode 13 made of a transparent conductive film and the semiconductor film 15 can be prevented, and the semiconductor film 15 and the intermediate film 37 can be prevented.
It is possible to improve the switching characteristics of the thin film transistor by utilizing the rectifying property of.

Next, a manufacturing method for forming the structure of the thin film transistor shown in FIG. 23 will be described with reference to the sectional views of FIGS.

First, as shown in FIG. 21, indium tin oxide (IT) is used as the material of the source / drain electrode 13 on the entire surface of the substrate 11 made of insulating glass.
An O) film as a transparent conductive film and titanium (Ti) as an intermediate film 37 material are sequentially formed.

This indium tin oxide film is formed with a film thickness of 200 nm using a sputtering device, and titanium, which is the material of the intermediate film 37, is formed with a film thickness of 50 nm using a sputtering device.

Then, a photoresist 27, which is a photosensitive material, is formed on the entire surface of the titanium film, which is a material for the intermediate film 37, by a spin coating method. Then, an exposure process and a development process are performed using a predetermined photomask to remove the photoresist 27.
Is patterned into the pattern shape of the source / drain electrode 13.

Then, using the patterned photoresist 27 as an etching mask, the titanium film and the indium tin oxide film are patterned by the reactive ion etching method to form the intermediate film 37 and the source / drain electrode 13 having the same pattern shape. To form.

The reactive ion etching treatment of this titanium film is carried out by using a reactive gas composed of a mixed gas of sulfur hexafluoride (SF ₆ ) and oxygen (O ₂ ) to carry out the reactive ion etching of the indium tin oxide film. The treatment is performed using a mixed gas of methane (CH ₄ ), carbon tetrachloride (CCl ₄ ) and hydrogen (H ₂ ) as a reaction gas.

Then, as shown in FIG. 22, the photoresist 27 on the intermediate film 37 is ashed to reduce the pattern size of the photoresist 27. The photoresist 27 is made smaller than the initial dimension by 0.1 μm to 0.2 μm by the ashing process.

By controlling the time of this ashing process for reducing the pattern size, the pattern size of the photoresist 27 is reduced by 0.1 μm to 0.2 μm, which is the size described above.

This ashing treatment is performed in a dry etching apparatus which is evacuated by the evacuation means to obtain 100 sccm to
Oxygen (O ₂ ) was introduced at a flow rate of 1000 sccm, and the pressure inside the apparatus was set to 100 mTorr to 300 mTorr.
1 high frequency power of 13.56MHz oscillation frequency
It is performed by using plasma generated by applying from 00W to 500W.

The size for reducing the pattern size of the photoresist 27 by this ashing process is controlled by the ashing time.

Next, as shown in FIG. 22, the photoresist 27 having a reduced pattern size is used as an etching mask to expose the intermediate film 3 exposed from the photoresist.
7 and the source / drain electrode 13 are etched to form a step in the source / drain electrode 13.

The etching of the intermediate film 37 exposed from the photoresist 27 is performed by the above-mentioned sulfur hexafluoride (SF).
₆ ) and oxygen (O ₂ ) are used as a reaction gas, and the etching process for forming a step on the source / drain electrode 13 is performed by using methane (CH ₄ ) and carbon tetrachloride as the reaction gas. It may be performed by reactive ion etching treatment using a mixed gas of (CCl ₄ ) and hydrogen (H ₂ ).

Then, the photoresist 27 used as the etching mask for patterning the source / drain electrodes 13 is removed. To remove the photoresist 27, a mixed solution of sulfuric acid (H ₂ SO ₄ ) and hydrogen peroxide (H ₂ O ₂ ) is used.

Next, as shown in FIG. 23, the material of the semiconductor film 15 made of non-single-crystal silicon is formed on the entire surface of the substrate 11 by 15 times.
It is formed with a thickness of 0 nm. The material of the semiconductor film 15 is formed by a plasma chemical vapor deposition apparatus using monosilane (SiH ₄ ) as a reaction gas.

Then, a gate insulating film 17 made of a silicon oxide (SiO ₂ ) film is formed on the entire surface of the material of the semiconductor film 15.
It is formed with a film thickness of 00 nm. This gate insulating film 17 is
Monosilane (SiH ₄ ) and oxygen (O ₂ ) as reaction gases
It is formed by a plasma chemical vapor deposition apparatus using and.

After that, a gate electrode 19 material made of a molybdenum (Mo) film is applied over the entire surface of the gate insulating film 17 material.
It is formed with a film thickness of 00 nm. This molybdenum film is formed using a sputtering device.

After that, a photoresist (not shown) which is a photosensitive material is formed on the entire surface of the material of the gate electrode 19 by spin coating. Then, an exposure process and a development process are performed using a predetermined photomask to pattern the photoresist into the pattern shape of the gate electrode 19.

Next, using the patterned photoresist as an etching mask, the molybdenum film is patterned by a wet etching method to form the gate electrode 19
To form

The gate electrode 19 made of this molybdenum film
Wet etching treatment of phosphoric acid (H ₃ PO ₄ ), nitric acid (HNO ₃ ), acetic acid (CH ₃ CO ₄ )
OH).

Then, using the photoresist as an etching mask, the material of the gate insulating film 17 and the material of the semiconductor film 15 are patterned by a reactive ion etching process to form the gate insulating film 17 and the semiconductor film 15.

[0224] The material of the gate insulating film 17 and the semiconductor film 15
The reactive ion etching treatment with the material is performed using a mixed gas of sulfur hexafluoride (SF ₆ ) and oxygen (O ₂ ) as an etching gas.

As described above, in the method of manufacturing a thin film transistor of the present invention, the photoresist 27 formed on the material of the source / drain electrode 13 is subjected to an ashing treatment to reduce its pattern size, and the source / drain electrode 13 having a step is formed. ing.

Therefore, in the present invention, the disorder of the crystallinity caused by the different growth directions of the film to be the semiconductor film 15 can be alleviated, and the deterioration or variation in the threshold voltage and mobility of the thin film transistor can be prevented. Can be made smaller. Further, the step coverage of the film provided on the source / drain electrode 13 is improved, the occurrence of disconnection in the step region of the source / drain electrode 13 can be prevented, and the occurrence of element defects in the thin film transistor can be suppressed.

Further, in the thin film transistor shown in FIG. 23, by providing the intermediate film 37, mutual reaction between the source / drain electrode 13 and the semiconductor film 15 can be prevented, and the rectifying property between the semiconductor film 15 and the intermediate film 37 can be utilized. Then
The switching characteristics of the thin film transistor can be improved.

In the thin film transistor of the embodiment described with reference to FIGS. 21 to 23, phosphorus (P) ions may be introduced into the intermediate film 37 as impurity ions.

When impurity ions are introduced into the intermediate film 37,
Phosphorus ions can be diffused into the semiconductor film 15 that is in contact with the intermediate film 37, and the conductivity type of the semiconductor film 15 can be N type.

When the conductivity type of the semiconductor film 15 is an N-type semiconductor as described above, the channel region of the thin film transistor is N-type.
It is possible to reduce the leak current and further reduce the connection resistance between the semiconductor film 15, the source / drain electrode 13, and the intermediate film 37.

In forming the intermediate film 37 containing the impurity ions, phosphine (PH ₃ ) is introduced as a reaction gas by using a reactive sputtering device to form titanium containing phosphorus ions.

In the method of manufacturing a thin film transistor described with reference to FIGS. 21 to 23, the source / drain electrode 13 material is patterned, and the pattern size of the photoresist 27 is reduced by ashing treatment. The embodiment has been described in which the source / drain electrode 13 material is again etched using the resist 27 as an etching mask to form the source / drain electrode 13 having steps.

However, as the manufacturing method for forming the step on the source / drain electrode 13 in the thin film transistor having the intermediate film 37, the source / drain electrode 1 may be formed by the processing steps described with reference to FIGS. 6 to 20.
A step can be formed at 3.

That is, after etching the material of the source / drain electrode 13 to the middle of the film thickness, the method of etching the photoresist 27, the method of softening the photoresist 27, the first photoresist 29 having a different pattern size and the first photoresist 29 having a different pattern size. The thin film transistor having the source / drain electrode 13 having a step can also be formed by the processing method using the second photoresist 31.

In the embodiment described with reference to FIGS. 1 to 23, the transparent conductive film is applied as the material of the source / drain electrode 13, but the source / drain electrode 13 material is not limited to the transparent conductive film. Aluminum (A
l), titanium (Ti), tantalum (Ta), molybdenum (Mo), tungsten (W), or alloy films of these materials can also be applied.

Next, a structure of a thin film transistor and a method of manufacturing the same in an embodiment different from the above description will be described.
The examples described below are the structure and the manufacturing method thereof when the thin film transistor is applied as a switching element of a liquid crystal display device. First, the structure of the thin film transistor according to the embodiment of the present invention will be described with reference to the sectional view of FIG.

As shown in FIG. 24, a light-shielding film 21 having a light-shielding property and made of a metal film and a capacitor lower electrode 23 are provided on a substrate 11 having an insulating property and made of glass. Further, an interlayer insulating film 33 is formed on the upper surface of the light shielding film 21 and the capacitor lower electrode 23.
Is provided.

Here, the light-shielding film 21 prevents the thin film transistor from being irradiated with light from the lower surface of the substrate 11 and prevents a light leak current from flowing through the thin film transistor. Therefore, the planar pattern shape of the light shielding film 21 is set to be approximately the same size as the thin film transistor or a slightly larger pattern shape.

Further, the capacitor lower electrode 23 is formed of the interlayer insulating film 3
The pixel electrode 25 provided on the upper surface of the
An insulating film-a metal structure capacitor is formed and connected to the drain of the thin film transistor. The capacitance serves to hold the applied voltage written through the data line until the next writing. That is, the pixel electrode 2
5 also serves as an upper electrode of the capacitor.

As described above, the interlayer insulating film 33 has a role as an insulating film for the data storage capacitor and a role as an insulating separation between the light shielding film 21 and the thin film transistor.

Further, the source / drain electrode 13 and the pixel electrode 23 connected to the drain are provided on the upper surface of the interlayer insulating film 33 so as to provide a gap therebetween. The source / drain electrode 13 and the pixel electrode 23 are made of a transparent conductive film.

A step is provided on the source / drain electrode 13, and the cross-sectional shape is stepwise. The size of the step provided on the source / drain electrode 13 is preferably about half the film thickness of the source / drain electrode 13. That is, the source / drain electrode 1 from the surface
3 A step having a depth dimension of about half the film thickness.

Source / drain electrode 13 having this step
A semiconductor film 15 made of a non-single crystal silicon film is provided on the
Further, a gate insulating film 17 made of a silicon oxide film is provided on the semiconductor film 15. Furthermore, a gate electrode 19 made of a molybdenum film is provided on the gate insulating film 17. Then, the semiconductor film 15 made of a silicon film becomes an active region of the thin film transistor.

Thus, a thin film transistor having the structure of the metal of the gate electrode 19, the insulating film of the gate insulating film 17, and the semiconductor of the semiconductor film 15 is formed.

In the thin film transistor structure of the present invention, as shown in FIG. 24, the source / drain electrode 13 is provided with a step and the cross-sectional shape is stepwise. When the step is provided on the source / drain electrode 13 in this manner, the step size of the semiconductor film 15 provided on the source / drain electrode 13 can be substantially reduced.

Therefore, in the side surface region of the patterned source / drain electrode 13 and the substrate 11, the disorder of crystallinity due to the different growth directions of the film to be the semiconductor film 15 can be alleviated. Therefore, it is possible to reduce the characteristics of the thin film transistor, in particular, the deterioration of the threshold voltage and the mobility and the variation thereof.

Further, in the thin film transistor of the present invention in which the source / drain electrode 13 is provided with a step, the step coverage of the film provided on the source / drain electrode 13 is improved. As a result, it is possible to suppress the occurrence of disconnection in the stepped region of the source / drain electrode 13 and prevent the occurrence of element defects in the thin film transistor.

Further, on the lower surface of the thin film transistor, a light shielding film 21 for preventing light irradiation to this thin film transistor.
Is provided. Therefore, it suppresses the flow of light leakage current in the thin film transistor.

Next, a manufacturing method for forming the thin film transistor structure shown in FIG. 24 will be described.

First, a tantalum (Ta) film having a light blocking property is formed on the entire surface of the substrate 11 as a material for the light blocking film 21 and the capacitor lower electrode 23. This tantalum film is 100
It is formed by a sputtering method to have a film thickness of nm.

After that, a photoresist (not shown) is formed on the entire surface of the tantalum film by a spin coating method, and an exposure process and a development process are performed using a predetermined photomask. It is formed in a pattern with the lower electrode 23.

Then, using the patterned photoresist as an etching mask, the tantalum film is patterned by the reactive ion etching method to shield the light-shielding film 2.
1 and the capacitor lower electrode 23 are formed.

The reactive ion etching treatment of this tantalum film was carried out using sulfur hexafluoride (SF) as an etching gas.
₆ ), oxygen (O ₂ ) and argon (Ar) mixed gas is used.

After that, the interlayer insulating film 33 made of a silicon oxide (SiO ₂ ) film is formed on the entire surface by chemical vapor deposition.
Is formed with a film thickness of 500 nm. This interlayer insulating film 33
Is formed by using monosilane (SiH ₄ ) and oxygen (O ₂ ) as reaction gases.

The source / drain electrode 13, the semiconductor film 15, the gate insulating film 17, and the gate electrode 19 can be subsequently formed by the same processing steps as those described with reference to FIGS. 1 to 20. , Detailed description is omitted.

Next, the structure of a thin film transistor and its manufacturing method in an embodiment different from the embodiment described with reference to FIG. 24 will be described. In the examples described below,
A structure and a manufacturing method when a thin film transistor is applied as a switching element of a liquid crystal display device. First, the structure of the thin film transistor according to the embodiment of the present invention will be described with reference to the sectional view of FIG.

As shown in FIG. 25, a light shielding film 21 having a light shielding property and made of a metal film and a capacitor lower electrode 23 are provided on a substrate 11 having an insulating property and made of glass. Further, an interlayer insulating film 33 is formed on the upper surface of the light shielding film 21 and the capacitor lower electrode 23.
Is provided.

Here, the light-shielding film 21 prevents the thin film transistor from being irradiated with light from the lower surface of the substrate 11 and prevents a light leak current from flowing through the thin film transistor. Therefore, the planar pattern shape of the light shielding film 21 is set to be approximately the same size as the thin film transistor or a slightly larger pattern shape.

Further, the capacitor lower electrode 23 is formed of the interlayer insulating film 3
The pixel electrode 25 provided on the upper surface of the
An insulating film-a metal structure capacitor is formed and connected to the drain of the thin film transistor. The capacitance serves to hold the applied voltage written through the data line until the next writing. That is, the pixel electrode 2
5 also serves as an upper electrode of the capacitor.

As described above, the interlayer insulating film 33 has a role as an insulating film of the data storage capacitor and a role as an insulating separation between the light shielding film 21 and the thin film transistor.

Further, the source / drain electrode 13 and the pixel electrode 23 connected to the drain are provided on the upper surface of the interlayer insulating film 33 so as to provide a gap therebetween. The source / drain electrode 13 and the pixel electrode 23 are made of a transparent conductive film.

A step is provided on the source / drain electrode 13, and the cross-sectional shape is stepwise. The size of the step provided on the source / drain electrode 13 is preferably about half the film thickness of the source / drain electrode 13. That is, a step having a depth dimension of about half the thickness of the source / drain electrode 13 is formed from the surface.

Source / drain electrode 13 having this step
An intermediate film 37 made of a titanium (Ti) film is provided on the top. Further, a semiconductor film 15 made of a non-single crystal silicon film is provided on the intermediate film 37, and a gate insulating film 17 made of a silicon oxide film is further provided on the semiconductor film 15. Furthermore, a gate electrode 19 made of a molybdenum film is provided on the gate insulating film 17. Then, the semiconductor film 15 made of a silicon film becomes an active region of the thin film transistor.

Here, the outer peripheral portion of the intermediate film 37 is the semiconductor film 1
The same pattern shape as the outer peripheral portion of No. 5 is used. Then, the semiconductor film 15 made of a silicon film becomes an active region of the thin film transistor.

Thus, a thin film transistor having a structure of the metal of the gate electrode 19, the insulating film of the gate insulating film 17, and the semiconductor of the semiconductor film 15 is formed.

In the thin film transistor structure of the present invention, as shown in FIG. 25, the source / drain electrode 13 is provided with a step, and its cross-sectional shape is stepwise. When the step is provided on the source / drain electrode 13 in this way, the step size of the semiconductor film 15 provided on the upper layer can be substantially reduced.

Therefore, in the side surface region of the patterned source / drain electrode 13 and the substrate 11, the disorder of crystallinity due to the different growth directions of the film to be the semiconductor film 15 can be alleviated. Therefore, it is possible to reduce the characteristics of the thin film transistor, in particular, the deterioration of the threshold voltage and the mobility and the variation thereof.

Further, in the thin film transistor of the present invention in which the source / drain electrode 13 is provided with a step, the step coverage of the film provided on the source / drain electrode 13 is good. As a result, it is possible to suppress the occurrence of disconnection in the stepped region of the source / drain electrode 13 and prevent the occurrence of element defects in the thin film transistor.

Further, on the lower surface of the thin film transistor, a light shielding film 21 for preventing light irradiation to this thin film transistor.
Is provided. Therefore, it suppresses the flow of light leakage current in the thin film transistor.

Further, in the thin film transistor shown in FIG. 25, by providing the intermediate film 37, mutual reaction between the source / drain electrode 13 made of a transparent conductive film and the semiconductor film 15 can be prevented, and the semiconductor film 15 and the intermediate film 37 can be prevented.
It is possible to improve the switching characteristics of the thin film transistor by utilizing the rectifying property of.

Next, a manufacturing method for forming the thin film transistor structure shown in FIG. 25 will be described.

First, a tantalum (Ta) film having a light blocking property is formed on the entire surface of the substrate 11 as a material for the light blocking film 21 and the capacitor lower electrode 23. This tantalum film is 100
It is formed by a sputtering method to have a film thickness of nm.

After that, a photoresist (not shown) is formed on the entire surface of the tantalum film by a spin coating method, and an exposure process and a development process are performed using a predetermined photomask, and the photoresist is used as a light shielding film 21 and a capacitor. It is formed in a pattern with the lower electrode 23.

Then, using the patterned photoresist as an etching mask, the tantalum film is patterned by the reactive ion etching method to shield the light-shielding film 2.
1 and the capacitor lower electrode 23 are formed.

The reactive ion etching treatment of this tantalum film was carried out by using sulfur hexafluoride (SF) as an etching gas.
₆ ), oxygen (O ₂ ) and argon (Ar) mixed gas is used.

After that, the interlayer insulating film 33 made of a silicon oxide (SiO ₂ ) film is formed on the entire surface by chemical vapor deposition.
Is formed with a film thickness of 500 nm. This interlayer insulating film 33
Is formed by using monosilane (SiH ₄ ) and oxygen (O ₂ ) as reaction gases.

After that, the source / drain electrode 13, the semiconductor film 15, the gate insulating film 17, and the gate electrode 19 are formed by the same process steps as those described with reference to FIGS. 1 to 20 and 21 to 23. Since it can be formed, detailed description is omitted.

In the embodiment described with reference to FIG. 25, phosphorus (P) ions may be introduced into the intermediate film 37 as impurity ions. When impurity ions are introduced into the intermediate film 37, phosphorus ions can be diffused into the semiconductor film 15 in contact with the intermediate film 37, and the conductivity type of the semiconductor film 15 can be N type.

As described above, when the conductivity type of the semiconductor film 15 is an N type semiconductor, the channel region of the thin film transistor is N type.
It is possible to reduce the leak current and further reduce the connection resistance between the semiconductor film 15, the source / drain electrode 13, and the intermediate film 37.

The intermediate film 37 containing the impurity ions may be formed by using a reactive sputtering apparatus and introducing phosphine (PH ₃ ) as a reaction gas to form titanium containing phosphorus ions.

Next, a structure of a thin film transistor and a method of manufacturing the same in an embodiment different from the embodiment described with reference to FIG. 25 will be described. In the examples described below,
A structure and a manufacturing method when a thin film transistor is applied as a switching element of a liquid crystal display device. First, the structure of the thin film transistor according to the embodiment of the present invention will be described with reference to the sectional view of FIG.

As shown in FIG. 26, a light-shielding film 21 made of a metal film having a light-shielding property and a capacitor lower electrode 23 are provided on a substrate 11 having an insulating property and made of glass. Further, a tantalum oxide film (Ta ₂ O) is formed on the surface of the capacitor lower electrode 23.
₅ ) An oxide film 35 composed of ₅ ) is provided. Furthermore, the light-shielding film 2
An interlayer insulating film 33 is provided on the upper surfaces of the capacitor 1 and the capacitor lower electrode 23.

Here, the light-shielding film 21 prevents the thin film transistor from being irradiated with light from the lower surface of the substrate 11 and prevents a light leak current from flowing through the thin film transistor. Therefore, the planar pattern shape of the light shielding film 21 is set to be approximately the same size as the thin film transistor or a slightly larger pattern shape.

Further, the lower capacitor electrode 23 forms a capacitor having a metal-insulating film-metal structure with the oxide film 35 on the surface thereof and the pixel electrode 25 provided on the upper surface thereof via the interlayer insulating film 33, and the drain of the thin film transistor. Connected to. The capacitance serves to hold the applied voltage written through the data line until the next writing.

Further, the oxide film 35 on the surface of the capacitor lower electrode 23 is formed.
Even when a film defect such as a pinhole occurs in the interlayer insulating film 37, the oxide film 35 works by the pixel electrode 25.
Has a role of preventing an electrical short circuit between the capacitor lower electrode 23 and the capacitor lower electrode 23.

As described above, the interlayer insulating film 33 has a role as an insulating film for the data storage capacitor and a role as an insulating separation between the light shielding film 21 and the thin film transistor.

Further, the source / drain electrode 13 and the pixel electrode 23 connected to the drain are provided on the upper surface of the interlayer insulating film 33 so as to provide a gap therebetween. The source / drain electrode 13 and the pixel electrode 23 are made of a transparent conductive film.

A step is provided on the source / drain electrode 13, and the cross-sectional shape is stepwise. The size of the step provided on the source / drain electrode 13 is preferably about half the film thickness of the source / drain electrode 13. That is, a step having a depth dimension of about half the thickness of the source / drain electrode 13 is formed from the surface.

Source / drain electrode 13 having this step
A semiconductor film 15 made of a non-single crystal silicon film is provided thereon, and a gate insulating film 17 made of a silicon oxide film is further provided on the semiconductor film 15. Furthermore, a gate electrode 19 made of a molybdenum film is provided on the gate insulating film 17. Then, the semiconductor film 15 made of a silicon film becomes an active region of the thin film transistor.

Thus, a thin film transistor having the structure of the metal of the gate electrode 19, the insulating film of the gate insulating film 17, and the semiconductor of the semiconductor film 15 is formed.

In the thin film transistor structure of the present invention, as shown in FIG. 26, the source / drain electrode 13 is provided with a step, and its cross-sectional shape is stepwise. When the step is provided on the source / drain electrode 13 in this way, the step size of the semiconductor film 15 provided on the upper layer can be substantially reduced.

Therefore, in the side surface region of the patterned source / drain electrode 13 and the substrate 11, the disorder of crystallinity due to the different growth directions of the film to be the semiconductor film 15 can be alleviated. Therefore, it is possible to reduce the characteristics of the thin film transistor, in particular, the deterioration of the threshold voltage and the mobility and the variation thereof.

Furthermore, in the thin film transistor of the present invention in which the source / drain electrode 13 is provided with a step, the step coverage of the film provided on the source / drain electrode 13 is good. As a result, it is possible to prevent the occurrence of disconnection in the step region of the source / drain electrode 13 and suppress the occurrence of device defects in the thin film transistor.

Further, on the lower surface of the thin film transistor, a light shielding film 21 for preventing light irradiation to this thin film transistor.
Is provided. Therefore, it suppresses the flow of light leakage current in the thin film transistor.

Further, in the thin film transistor shown in FIG. 26, the oxide film 35 is provided on the surface of the capacitor lower electrode 23. Even when a film defect such as a pinhole occurs in the interlayer insulating film 37, the oxide film 35 can prevent an electrical short circuit between the pixel electrode 25 and the capacitor lower electrode 23 due to the function of the oxide film 35. .

Next, a manufacturing method for forming the thin film transistor structure shown in FIG. 26 will be described.

First, as shown in FIG. 26, the substrate 1
A tantalum (Ta) film having a light blocking property is formed as a material for the light blocking film 21 and the capacitor lower electrode 23 on the entire surface of 1. This tantalum film has a thickness of 100 nm and is formed by a sputtering method.

After that, a photoresist (not shown) is formed on the entire surface of the tantalum film by a spin coating method, and an exposure process and a development process are performed using a predetermined photomask. It is formed in a pattern with the lower electrode 23.

Thereafter, using the patterned photoresist as an etching mask, the tantalum film is patterned by the reactive ion etching method to shield the light-shielding film 2.
1 and the capacitor lower electrode 23 are formed.

The reactive ion etching treatment of this tantalum film was carried out using sulfur hexafluoride (SF) as an etching gas.
₆ ), oxygen (O ₂ ) and argon (Ar) mixed gas is used.

After that, an oxide film 35 is formed to a thickness of 50 nm on the surface of the capacitor lower electrode 23. The oxide film 35 is formed by anodizing treatment in which citric acid is used as an anodizing solution and a DC voltage is applied between the platinum plate and the tantalum film.

After that, the interlayer insulating film 33 made of a silicon oxide (SiO ₂ ) film is formed on the entire surface by chemical vapor deposition.
Is formed with a film thickness of 500 nm. This interlayer insulating film 33
Is formed by using monosilane (SiH ₄ ) and oxygen (O ₂ ) as reaction gases.

After that, the source / drain electrode 13, the semiconductor film 15, the gate insulating film 17, and the gate electrode 19 are formed by the same process steps as those described with reference to FIGS. 1 to 20 and 21 to 23. Since it can be formed, detailed description is omitted.

Also in the embodiment described with reference to FIG. 26,
An intermediate film made of a titanium (Ti) film may be provided between the source / drain electrode 13 and the semiconductor film 15.

By providing the intermediate film, it is possible to prevent mutual reaction between the source / drain electrode 13 made of the transparent conductive film and the semiconductor film 15, and to utilize the rectifying property between the semiconductor film 15 and the intermediate film to switch the thin film transistor. The characteristics can be improved.

Further, in the embodiment described with reference to FIG. 26, phosphorus (P) ions may be introduced as impurity ions into the intermediate film. When impurity ions are introduced into this intermediate film, phosphorus ions can be diffused into the semiconductor film 15 in contact with this intermediate film, and the conductivity type of the semiconductor film 15 is N.
Type.

As described above, when the conductivity type of the semiconductor film 15 is an N type semiconductor, the channel region of the thin film transistor is N type.
It can be formed into a mold, the leak current can be reduced, and the connection resistance between the semiconductor film 15, the source / drain electrode 13, and the intermediate film can be reduced.

The intermediate film 37 containing the impurity ions may be formed by using a reactive sputtering apparatus to introduce phosphine (PH ₃ ) as a reaction gas to form titanium containing phosphorus ions.

In the above description of the embodiments, the gate electrode 19
As an example, although molybdenum (Mo) is used as an example, other than molybdenum, tantalum (Ta) or titanium (T) is used.
i), aluminum (Al), tungsten (W),
Alternatively, these alloy films can also be applied.

Further, as the impurity ions added to the intermediate film 37, in addition to phosphorus (P) ions, impurity ions of nitrogen (N), boron (B) or arsenic (As) can be applied.

Further, although a non-single-crystal silicon film made of an amorphous silicon film or a polycrystalline silicon film is applied as the semiconductor film 15 in the present invention, these films are irradiated with argon laser light to increase the grain size. The non-single-crystal silicon film, the single-crystal silicon film, or the semiconductor film in which the single-crystal silicon film and the non-single-crystal silicon film are mixed can be applied in the present invention.

Further, although the silicon oxide film is used as the gate insulating film 17 in the above-described embodiment, a silicon nitride film, a tantalum oxide film, a silicon oxynitride film, an aluminum oxide film, or a film of these films is used in addition to the silicon oxide film. The composite film of the film can also be applied in the present invention as a gate insulating film.

Further, in the embodiment of the present invention described above, the silicon oxide film is used as the interlayer insulating film 33. However, in addition to the silicon oxide film, a silicon oxide film containing phosphorus or boron, a silicon nitride film, or an oxide film is used. A tantalum film, a polyimide film which is an organic resin insulating film, or a color filter film can also be applied as the interlayer insulating film 33.

Alternatively, as the interlayer insulating film 33, a coated glass (SOG) film may be used. This coated glass film is a mixture of silicon oxide and a solvent. After being formed on the substrate 11 by the spin coating method, it is heated at a temperature of 250 ° C. to 300 ° C. to evaporate the solvent in the coated glass film. Form.

Further, in the above description of the embodiments, one step is provided as the step provided on the source / drain electrode 13, but in the thin film transistor of the present invention, a plurality of steps may be provided on the source / drain electrode 13. Good.

By providing a plurality of steps on the source / drain electrode 13 as described above, the substantial step size of the semiconductor film 15 on the source / drain electrode 13 can be further reduced, and the threshold voltage and the movement can be further increased. It is possible to improve the characteristics of the thin film transistor each time and reduce the variation.

As a method of forming the source / drain electrode having a plurality of steps, a method of ashing a photoresist used as an etching mask of the source / drain electrode a plurality of times, a method of patterning using a plurality of photomasks, and A manufacturing method in which the above processing methods are combined may be adopted.

[0318]

As is apparent from the above description, in the thin film transistor structure in the embodiment of the present invention, the source / drain electrode is provided with a step and the cross-sectional shape is stepwise. When the step is provided on the source / drain electrode in this manner, the step size of the semiconductor film provided on the upper layer can be substantially reduced.

Therefore, in the patterned side surface region of the source / drain electrode and the substrate, the disorder of crystallinity due to the different growth directions of the film to be the semiconductor film can be alleviated.

Therefore, it is possible to reduce the characteristics of the thin film transistor, especially the deterioration of the threshold voltage and the mobility and the variation thereof.

Further, in the thin film transistor of the present invention in which the source / drain electrode is provided with a step, the step coverage of the film provided on the source / drain electrode becomes good. As a result, it is possible to suppress the occurrence of disconnection in the step region of the source / drain electrode and prevent the occurrence of element defects in the thin film transistor.

Further, in the thin film transistor in the example of the present invention, the intermediate film is provided between the source / drain electrode and the semiconductor film. As a result, mutual reaction between the source / drain electrode and the semiconductor film can be prevented, and the switching characteristic of the thin film transistor can be improved by utilizing the rectifying property between the semiconductor film and the intermediate film.

Further, in the thin film transistor in the embodiment of the present invention, impurity ions may be introduced into the intermediate film. When impurity ions are introduced into this intermediate film, the impurity ions can be diffused into the semiconductor film in contact with this intermediate film, the leak current of the thin film transistor can be reduced, and further, the semiconductor film, the source / drain electrode and the intermediate film can be mutually The connection resistance of can be lowered.

Further, on the lower surface of the thin film transistor of the present invention, a light shielding film for preventing light irradiation to the thin film transistor is provided. Therefore, it suppresses the flow of light leakage current in the thin film transistor.

Further, in the thin film transistor of the present invention, an oxide film is provided on the surface of the capacitor lower electrode. This oxide film can prevent an electrical short circuit between the pixel electrode and the capacitor lower electrode due to the function of the oxide film even when a film defect such as a pinhole occurs in the interlayer insulating film.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a structure of a thin film transistor and a method of manufacturing the thin film transistor according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a structure of a thin film transistor and a method of manufacturing the thin film transistor according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a structure of a thin film transistor and a method of manufacturing the thin film transistor according to an embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a structure of a thin film transistor and a method of manufacturing the thin film transistor according to an embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a structure of a thin film transistor and a method of manufacturing the thin film transistor according to an embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a structure of a thin film transistor and a method of manufacturing the thin film transistor according to an embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a structure of a thin film transistor and a method of manufacturing the thin film transistor according to an embodiment of the present invention.

FIG. 8 is a cross-sectional view showing a structure of a thin film transistor and a method of manufacturing the thin film transistor according to an embodiment of the present invention.

FIG. 9 is a cross-sectional view showing the structure of the thin film transistor and the method for manufacturing the thin film transistor according to the embodiment of the present invention.

FIG. 10 is a cross-sectional view showing the structure of the thin film transistor and the method for manufacturing the thin film transistor according to the embodiment of the present invention.

FIG. 11 is a cross-sectional view showing the structure of the thin film transistor and the method for manufacturing the thin film transistor according to the embodiment of the present invention.

FIG. 12 is a cross-sectional view showing the structure of the thin film transistor and the method for manufacturing the thin film transistor according to the embodiment of the present invention.

FIG. 13 is a cross-sectional view showing the structure of the thin film transistor and the method for manufacturing the thin film transistor according to the embodiment of the present invention.

FIG. 14 is a cross-sectional view showing the structure of the thin film transistor and the method for manufacturing the thin film transistor according to the embodiment of the present invention.

FIG. 15 is a cross-sectional view showing the structure of the thin film transistor and the method for manufacturing the thin film transistor according to the embodiment of the present invention.

FIG. 16 is a cross-sectional view showing the structure of the thin film transistor and the method for manufacturing the thin film transistor in the example of the present invention.

FIG. 17 is a cross-sectional view showing the structure of the thin film transistor and the method for manufacturing the thin film transistor according to the embodiment of the present invention.

FIG. 18 is a cross-sectional view showing the structure of the thin film transistor and the method for manufacturing the thin film transistor in the example of the present invention.

FIG. 19 is a cross-sectional view showing the structure of the thin film transistor and the method for manufacturing the thin film transistor in the example of the present invention.

FIG. 20 is a cross-sectional view showing the structure of the thin film transistor and the method for manufacturing the same according to the embodiment of the present invention.

FIG. 21 is a cross-sectional view showing the structure of the thin film transistor and the method for manufacturing the thin film transistor in the example of the present invention.

FIG. 22 is a cross-sectional view showing the structure of the thin film transistor and the manufacturing method thereof according to the example of the present invention.

FIG. 23 is a cross-sectional view showing the structure of the thin film transistor and the method for manufacturing the thin film transistor in the example of the present invention.

FIG. 24 is a cross-sectional view showing the structure of the thin film transistor and the manufacturing method thereof according to the example of the present invention.

FIG. 25 is a cross-sectional view showing the structure of the thin film transistor and the method for manufacturing the thin film transistor according to the embodiment of the present invention.

FIG. 26 is a cross-sectional view showing the structure of the thin film transistor and the method for manufacturing the thin film transistor in the example of the present invention.

FIG. 27 is a cross-sectional view showing a structure of a thin film transistor and a method of manufacturing the thin film transistor in the related art.

[Description of Reference Signs] 11 substrate 13 source / drain electrode 15 semiconductor film 17 gate insulating film 19 gate electrode 27 photoresist 35 oxide film 37 intermediate film

Claims (40)

[Claims] 1. A source / drain electrode provided on a substrate,
A thin film transistor comprising a semiconductor film provided on a source / drain electrode, a gate insulating film provided on the semiconductor film, and a gate electrode provided on the gate insulating film, wherein a cross-sectional shape of the source / drain electrode has a step. 2. A source / drain electrode provided on a substrate,
An intermediate film provided on the source / drain electrode, a semiconductor film provided on the intermediate film, and a gate insulating film provided on the semiconductor film,
A thin film transistor comprising: a gate electrode provided on a gate insulating film; and a cross-sectional shape of the source / drain electrode having a step. 3. A source / drain electrode provided on a substrate,
The source / drain electrode has an intermediate film containing impurities, a semiconductor film provided on the intermediate film, a gate insulating film provided on the semiconductor film, and a gate electrode provided on the gate insulating film. Is a thin film transistor having a step. 4. A light-shielding film provided on a substrate, an interlayer insulating film provided on the light-shielding film, a source / drain electrode provided on the interlayer insulating film, a semiconductor film provided on the source / drain electrode, and a semiconductor film provided on the semiconductor film. A thin film transistor comprising a gate insulating film and a gate electrode provided on the gate insulating film, wherein the source / drain electrode has a stepped cross-sectional shape. 5. A light-shielding film provided on a substrate, an interlayer insulating film provided on the light-shielding film, a source / drain electrode provided on the upper surface of the interlayer insulating film, an intermediate film provided on the source / drain electrode, and an intermediate film provided on the intermediate film. A thin film transistor comprising a semiconductor film, a gate insulating film provided on the semiconductor film, and a gate electrode provided on the gate insulating film, wherein the source / drain electrode has a stepped cross-sectional shape. 6. A light-shielding film provided on a substrate, an interlayer insulating film provided on the light-shielding film, a source / drain electrode provided on the interlayer insulating film, an intermediate film containing impurities provided on the source / drain electrode, and an intermediate film. A thin film transistor comprising a semiconductor film provided on the semiconductor film, a gate insulating film provided on the semiconductor film, and a gate electrode provided on the gate insulating film, wherein the source / drain electrode has a stepped cross-sectional shape. 7. A light-shielding film and a capacitor lower electrode provided on a substrate, an interlayer insulating film provided on the light-shielding film and the capacitor lower electrode, a source drain electrode provided on the interlayer insulating film, and a semiconductor film provided on the source drain electrode. And a gate insulating film provided on the semiconductor film, and a gate electrode provided on the gate insulating film, wherein a cross-sectional shape of the source / drain electrode has a step. 8. A light-shielding film and a capacitor lower electrode provided on a substrate, an interlayer insulating film provided on the light-shielding film and the capacitor lower electrode, a source / drain electrode provided on the interlayer insulating film, and an intermediate film provided on the source / drain electrode. A thin film transistor, comprising: a semiconductor film provided on the intermediate film; a gate insulating film provided on the semiconductor film; and a gate electrode provided on the gate insulating film, wherein the source / drain electrode has a stepped cross-sectional shape. 9. A light-shielding film and a capacitor lower electrode provided on the substrate, an interlayer insulating film provided on the upper surface of the light-shielding film and the capacitor lower electrode,
A source / drain electrode provided on the interlayer insulating film, an intermediate film containing impurities provided on the source / drain electrode, a semiconductor film provided on the intermediate film, a gate insulating film provided on the semiconductor film, and a gate provided on the gate insulating film. A thin film transistor, comprising: an electrode; and a cross-sectional shape of the source / drain electrode having a step. 10. A light-shielding film and a capacitor lower electrode provided on a substrate, an oxide film provided on the upper surface of the capacitor lower electrode, an interlayer insulating film provided on the light-shielding film and the oxide film, and a source / drain electrode provided on the interlayer insulating film. And a semiconductor film provided on the source / drain electrode, a gate insulating film provided on the semiconductor film, and a gate electrode provided on the gate insulating film, and a cross-sectional shape of the source / drain electrode has a step. . 11. A light-shielding film and a capacitor lower electrode provided on a substrate, an oxide film provided on the capacitor lower electrode, an interlayer insulating film provided on the light-shielding film and the oxide film, and a source / drain electrode provided on the interlayer insulating film. An intermediate film provided on the source / drain electrode, a semiconductor film provided on the intermediate film, a gate insulating film provided on the semiconductor film, and a gate electrode provided on the gate insulating film. A thin film transistor having: 12. A light-shielding film and a capacitor lower electrode provided on a substrate, an oxide film provided on the capacitor lower electrode, an interlayer insulating film provided on the light-shielding film and the oxide film, and a source / drain electrode provided on the interlayer insulating film. An intermediate film containing impurity ions provided on the source / drain electrode, a semiconductor film provided on the intermediate film, a gate insulating film provided on the semiconductor film, and a gate electrode provided on the gate insulating film. A thin film transistor having a cross-sectional shape having steps. 13. A source / drain electrode material is formed on a substrate, a photoresist is formed on the source / drain electrode material, the source / drain electrode material is etched using the photoresist as an etching mask, and the photoresist is ashed. Further, a step of forming a source / drain electrode by etching the source / drain electrode material up to the middle of the film thickness using a photoresist as an etching mask, and a semiconductor film material, a gate insulating film material, and a gate electrode material are sequentially formed, Forming a photoresist on the gate electrode material, and etching the semiconductor film material, the gate insulating film material, and the gate electrode material using the photoresist as an etching mask to form the semiconductor film, the gate insulating film, and the gate electrode A method of manufacturing a thin film transistor, comprising: Law. 14. A source / drain electrode material and an intermediate film are formed on a substrate, a photoresist is formed on the intermediate film, and the intermediate film and the source / drain electrode material are etched by using the photoresist as an etching mask to form a photoresist. Ashing, and then using the photoresist as an etching mask to etch the intermediate film and further etching to the middle of the film thickness of the source / drain electrode material to form the source / drain electrode, and the semiconductor film material and the gate insulating film material. And a gate electrode material are sequentially formed, and a photoresist is formed on the gate electrode material, and the semiconductor film material, the gate insulating film material, and the gate electrode material are etched by using the photoresist as an etching mask. And a step of forming a gate insulating film and a gate electrode. Method of manufacturing thin film transistor. 15. A source / drain electrode material is formed on a substrate, a photoresist is formed on the source / drain electrode material, and the photoresist is used as an etching mask to etch the source / drain electrode material up to the middle of the film thickness. A step of ashing the resist, further etching the source / drain electrode material by using the photoresist as an etching mask to form a source / drain electrode, and sequentially forming a semiconductor film material, a gate insulating film material, and a gate electrode material, Forming a photoresist on the gate electrode material, and etching the semiconductor film material, the gate insulating film material, and the gate electrode material using the photoresist as an etching mask to form the semiconductor film, the gate insulating film, and the gate electrode A method of manufacturing a thin film transistor, comprising: Law. 16. A source / drain electrode material and an intermediate film are formed on a substrate, a photoresist is formed on the intermediate film, the intermediate film is etched by using the photoresist as an etching mask, and the film thickness of the source / drain electrode material is further formed. Etching halfway through, ashing the photoresist,
Further, the step of etching the intermediate film and the source / drain electrode material by using the photoresist as an etching mask to form the source / drain electrode, the semiconductor film material, the gate insulating film material, and the gate electrode material are sequentially formed, and the gate electrode material is formed. Forming a semiconductor film, a gate insulating film, and a gate electrode by etching a semiconductor film material, a gate insulating film material, and a gate electrode material using the photoresist as an etching mask; A method of manufacturing a thin film transistor, comprising: 17. A source / drain electrode material is formed on a substrate, a photoresist is formed on the source / drain electrode material, and the photoresist is used as an etching mask to etch the source / drain electrode material up to the middle of the film thickness. A step of forming a source / drain electrode by heat-treating the resist to soften it and further using the photoresist as an etching mask to form the source / drain electrode material, a semiconductor film material, a gate insulating film material, and a gate electrode material are sequentially performed. Forming and forming a photoresist on the gate electrode material, and using the photoresist as an etching mask to etch the semiconductor film material, the gate insulating film material, and the gate electrode material to form the semiconductor film, the gate insulating film, and the gate electrode And a step of forming Construction method. 18. A source / drain electrode material is formed on a substrate, a first photoresist is formed on the source / drain electrode material, and the source / drain electrode material is etched by using the photoresist as an etching mask. The photoresist is removed, and a second pattern having a smaller pattern size than the first photoresist is formed on the source / drain electrode material.
Forming a photoresist, and using the second photoresist as an etching mask to etch the source / drain electrode material to the middle of the film thickness to form a source / drain electrode; a semiconductor film material, a gate insulating film material, and a gate. A step of sequentially forming an electrode material and forming a photoresist on the gate electrode material, and a step of etching the semiconductor film material, the gate insulating film material, and the gate electrode material using the photoresist as an etching mask to form the semiconductor film and the gate. And a step of forming an insulating film and a gate electrode. 19. A source / drain electrode material is formed on a substrate, a first photoresist is formed on the source / drain electrode material, and the source / drain electrode material is etched halfway through the film thickness using the photoresist as an etching mask. Then, the first photoresist is removed, and a second photoresist having a pattern size smaller than that of the first photoresist is formed on the source / drain electrode material, and the second photoresist is used as an etching mask to form the source / drain. A step of etching the electrode material to form a source / drain electrode, a step of sequentially forming a semiconductor film material, a gate insulating film material, and a gate electrode material, and forming a photoresist on the gate electrode material, and etching the photoresist. Etching semiconductor film material, gate insulating film material, and gate electrode material using as a mask And a step of forming a semiconductor film, a gate insulating film, and a gate electrode. 20. A source / drain electrode material is formed on a substrate, a first photoresist is formed on the source / drain electrode material, and a film thickness of the source / drain electrode material is adjusted by using the first photoresist as an etching mask. Etching is performed halfway to remove the first photoresist, and then a second photoresist having a pattern size larger than that of the first photoresist is formed on the source / drain electrode material.
The step of etching the source / drain electrode material by using the photoresist as an etching mask to form the source / drain electrode, the semiconductor film material, the gate insulating film material, and the gate electrode material are sequentially formed, and the photoresist is formed on the gate electrode material. And a step of forming a semiconductor film, a gate insulating film, and a gate electrode by etching the semiconductor film material, the gate insulating film material, and the gate electrode material using a photoresist as an etching mask. A method of manufacturing a thin film transistor, comprising: 21. A light-shielding film material is formed on a substrate, a photoresist is formed on the light-shielding film material, and the light-shielding film material is etched by using the photoresist as an etching mask to form a light-shielding film. And a source / drain electrode material is formed on the interlayer insulating film, a photoresist is formed on the source / drain electrode material, and the source / drain electrode material is etched using the photoresist as an etching mask. Ashing treatment, and further using a photoresist as an etching mask to form a source / drain electrode by etching to the middle of the film thickness of the source / drain electrode material, and a semiconductor film material, a gate insulating film material, and a gate electrode material. Formed sequentially,
Forming a photoresist on the gate electrode material,
Manufacture of a thin film transistor, which comprises a step of etching a semiconductor film material, a gate insulating film material, and a gate electrode material using a photoresist as an etching mask to form a semiconductor film, a gate insulating film, and a gate electrode. Method. 22. A light-shielding film material is formed on a substrate, a photoresist is formed on the light-shielding film material, and the light-shielding film material is etched by using the photoresist as an etching mask to form a light-shielding film. And a source / drain electrode material and an intermediate film are formed on the interlayer insulating film,
A photoresist is formed on the intermediate film, the photoresist is used as an etching mask to etch the intermediate film and the source / drain electrode material, the photoresist is ashed, and the photoresist is used as an etching mask. A step of forming a source / drain electrode by etching to an intermediate thickness of the electrode material; a step of sequentially forming a semiconductor film material, a gate insulating film material, and a gate electrode material, and forming a photoresist on the gate electrode material. And a step of etching a semiconductor film material, a gate insulating film material, and a gate electrode material using a photoresist as an etching mask to form a semiconductor film, a gate insulating film, and a gate electrode. Production method. 23. A light-shielding film material is formed on a substrate, a photoresist is formed on the light-shielding film material, the light-shielding film material is etched using the photoresist as an etching mask to form a light-shielding film, and an interlayer insulating film is formed. And a source / drain electrode material is formed on the interlayer insulating film, a photoresist is formed on the source / drain electrode material, and the photoresist is used as an etching mask to reach the middle of the thickness of the source / drain electrode material. The steps of etching, ashing the photoresist, and etching the source / drain electrode material by using the photoresist as an etching mask to form the source / drain electrode, and the semiconductor film material, the gate insulating film material, and the gate electrode material are performed. Formed sequentially,
Forming a photoresist on the gate electrode material,
Manufacture of a thin film transistor, which comprises a step of etching a semiconductor film material, a gate insulating film material, and a gate electrode material using a photoresist as an etching mask to form a semiconductor film, a gate insulating film, and a gate electrode. Method. 24. A light-shielding film material is formed on a substrate, a photoresist is formed on the light-shielding film material, and the light-shielding film material is etched by using the photoresist as an etching mask to form a light-shielding film. And a source / drain electrode material and an intermediate film are formed on the interlayer insulating film,
A photoresist is formed on the intermediate film, the photoresist is used as an etching mask, the intermediate film and the source / drain electrode material are etched to the middle of the film thickness, the photoresist is ashed, and the photoresist is used as an etching mask. A step of etching the intermediate film and the source / drain electrode material to form a source / drain electrode; a step of sequentially forming a semiconductor film material, a gate insulating film material, and a gate electrode material, and forming a photoresist on the gate electrode material. And a step of etching a semiconductor film material, a gate insulating film material, and a gate electrode material using a photoresist as an etching mask to form a semiconductor film, a gate insulating film, and a gate electrode. Production method. 25. A light-shielding film material is formed on a substrate, a photoresist is formed on the light-shielding film material, and the light-shielding film material is etched by using the photoresist as an etching mask to form a light-shielding film. And the step of forming a source / drain electrode material on the interlayer insulating film, a photoresist is formed on the source / drain electrode material, and the photoresist is used as an etching mask to etch the source / drain electrode material to the middle of its thickness. Then, the photoresist is heat-treated to be softened, and the source / drain electrode is formed by etching the source / drain electrode material using the photoresist as an etching mask, and the semiconductor film material, the gate insulating film material, and the gate electrode material. And are sequentially formed,
Forming a photoresist on the gate electrode material,
Manufacture of a thin film transistor, which comprises a step of etching a semiconductor film material, a gate insulating film material, and a gate electrode material using a photoresist as an etching mask to form a semiconductor film, a gate insulating film, and a gate electrode. Method. 26. A light-shielding film material is formed on a substrate, a photoresist is formed on the light-shielding film material, and the light-shielding film material is etched by using the photoresist as an etching mask to form a light-shielding film. Forming a source / drain electrode material on the interlayer insulating film, forming a first photoresist on the source / drain electrode material, and etching the source / drain electrode material using the photoresist as an etching mask, The first photoresist is removed, a second photoresist having a pattern size smaller than that of the first photoresist is further formed on the source / drain electrode material, and the second photoresist is used as an etching mask to form the source / drain electrode material. Of forming the source / drain electrodes by etching to the middle of the film thickness of the semiconductor film material and the gate insulating film A step of sequentially forming a material and a gate electrode material, and forming a photoresist on the gate electrode material; and a step of etching the semiconductor film material, the gate insulating film material, and the gate electrode material using the photoresist as an etching mask to form a semiconductor A method of manufacturing a thin film transistor, comprising the steps of forming a film, a gate insulating film, and a gate electrode. 27. A light-shielding film material is formed on a substrate, a photoresist is formed on the light-shielding film material, the light-shielding film material is etched using the photoresist as an etching mask to form a light-shielding film, and an interlayer insulating film is formed. Forming a source / drain electrode material on the interlayer insulating film, forming a first photoresist on the source / drain electrode material, and using the photoresist as an etching mask Etching halfway to remove the first photoresist, form a second photoresist having a smaller pattern size than the first photoresist on the source / drain electrode material, and use the second photoresist as an etching mask. Etching the source / drain electrode material to form the source / drain electrode, and the semiconductor film material and the gate insulating film. A step of sequentially forming a material and a gate electrode material, and forming a photoresist on the gate electrode material; and a step of etching the semiconductor film material, the gate insulating film material, and the gate electrode material using the photoresist as an etching mask to form a semiconductor A method of manufacturing a thin film transistor, comprising the steps of forming a film, a gate insulating film, and a gate electrode. 28. A light-shielding film material is formed on a substrate, a photoresist is formed on the light-shielding film material, and the light-shielding film material is etched by using the photoresist as an etching mask to form a light-shielding film. And a source / drain electrode material is formed on the interlayer insulating film, a first photoresist is formed on the source / drain electrode material, and the source / drain electrode material is formed by using the first photoresist as an etching mask. Etching to the middle of the film thickness of
Of the photoresist is removed, a second photoresist having a pattern size larger than that of the first photoresist is formed on the source / drain electrode material, and the source / drain electrode material is etched using the second photoresist as an etching mask. To form a source / drain electrode, a semiconductor film material, a gate insulating film material, and a gate electrode material are sequentially formed, and a photoresist is formed on the gate electrode material, and the photoresist is used as an etching mask. A method of manufacturing a thin film transistor, comprising the steps of etching a semiconductor film material, a gate insulating film material, and a gate electrode material to form a semiconductor film, a gate insulating film, and a gate electrode. 29. A material forming a light-shielding film and a capacitor lower electrode is formed on a substrate, a photoresist is formed on a material forming a light-shielding film and a capacitor lower electrode, and the light-shielding film and the capacitor are formed by using the photoresist as an etching mask. The step of forming a light-shielding film and a capacitor lower electrode by etching the material to be the lower electrode, forming an interlayer insulating film, forming a source / drain electrode material on the interlayer insulating film, and applying a photoresist on the source / drain electrode material. The source / drain electrode material is etched using the photoresist as an etching mask, the photoresist is ashed, and the photoresist is used as an etching mask to etch the source / drain electrode material up to the middle of the film thickness of the source / drain. The step of forming the electrode, the semiconductor film material, the gate insulating film material, and the gate electrode material are sequentially formed. A step of forming a photoresist on the gate electrode material, and using the photoresist as an etching mask to etch the semiconductor film material, the gate insulating film material, and the gate electrode material to form the semiconductor film, the gate insulating film, and the gate electrode. And a step of forming the thin film transistor. 30. A material forming a light-shielding film and a capacitor lower electrode is formed on a substrate, a photoresist is formed on a material forming a light-shielding film and a capacitor lower electrode, and the light-shielding film and the capacitor are formed by using the photoresist as an etching mask. The step of etching the material to be the lower electrode to form the light-shielding film and the capacitor lower electrode, forming the interlayer insulating film, the source / drain electrode material and the intermediate film on the interlayer insulating film, and the photoresist on the intermediate film. Is formed, the photoresist is used as an etching mask to etch the intermediate film and the source / drain electrode material, the photoresist is ashed, and the photoresist is used as an etching mask to adjust the film thickness of the intermediate film and the source / drain electrode material. The process of forming the source / drain electrodes by halfway etching, the semiconductor film material, the gate insulating film material, and the gate electrode material are sequentially performed. Next, a step of forming a photoresist on the gate electrode material, and using the photoresist as an etching mask to etch the semiconductor film material, the gate insulating film material, and the gate electrode material, the semiconductor film, the gate insulating film, and the gate And a step of forming an electrode. 31. A material forming a light-shielding film and a capacitor lower electrode is formed on a substrate, a photoresist is formed on a material forming a light-shielding film and a capacitor lower electrode, and the light-shielding film and the capacitor are formed by using the photoresist as an etching mask. The step of forming a light-shielding film and a capacitor lower electrode by etching the material for the lower electrode, forming an oxide film on the capacitor lower electrode, and forming an interlayer insulating film, and forming a source / drain electrode material on the interlayer insulating film. Then, a photoresist is formed on the source / drain electrode material, the source / drain electrode material is etched by using the photoresist as an etching mask, the photoresist is ashed, and the source / drain electrode material is further used by using the photoresist as an etching mask. Of forming the source / drain electrodes by etching to the middle of the film thickness of the semiconductor film material and the gate insulating film material And a gate electrode material are sequentially formed, and a photoresist is formed on the gate electrode material, and the semiconductor film material, the gate insulating film material, and the gate electrode material are etched by using the photoresist as an etching mask to form a semiconductor. A method of manufacturing a thin film transistor, comprising the steps of forming a film, a gate insulating film, and a gate electrode. 32. A material forming a light-shielding film and a capacitor lower electrode is formed on a substrate, a photoresist is formed on a material forming a light-shielding film and a capacitor lower electrode, and the light-shielding film and the capacitor are formed by using the photoresist as an etching mask. A step of forming a light-shielding film and a capacitor lower electrode by etching a material to be a lower electrode, forming an oxide film on the capacitor lower electrode, and forming an interlayer insulating film, and a step of forming a source drain electrode material and an intermediate layer on the interlayer insulating film. A film is formed, a photoresist is formed on the intermediate film, the intermediate film and the source / drain electrode material are etched using the photoresist as an etching mask, the photoresist is ashed, and the photoresist is used as an etching mask. A step of forming a source / drain electrode by etching up to the middle of the film thickness of the intermediate film and the source / drain electrode material;
A step of sequentially forming a semiconductor film material, a gate insulating film material, and a gate electrode material, and forming a photoresist on the gate electrode material; and a semiconductor film material, a gate insulating film material, and a gate electrode using the photoresist as an etching mask. And a step of etching a material to form a semiconductor film, a gate insulating film, and a gate electrode. 33. A material forming a light-shielding film and a capacitor lower electrode is formed on a substrate, a photoresist is formed on a material forming a light-shielding film and a capacitor lower electrode, and the light-shielding film and the capacitor are formed by using the photoresist as an etching mask. The step of forming a light-shielding film and a capacitor lower electrode by etching the material to be the lower electrode, forming an interlayer insulating film, forming a source / drain electrode material on the interlayer insulating film, and applying a photoresist on the source / drain electrode material. After forming, the photoresist is used as an etching mask to etch the source / drain electrode material to the middle of the film thickness, the photoresist is ashed, and the photoresist is used as an etching mask to etch the source / drain electrode material to form the source / drain. The step of forming the electrode, the semiconductor film material, the gate insulating film material, and the gate electrode material are sequentially formed. A step of forming a photoresist on the gate electrode material, and using the photoresist as an etching mask to etch the semiconductor film material, the gate insulating film material, and the gate electrode material to form the semiconductor film, the gate insulating film, and the gate electrode. And a step of forming the thin film transistor. 34. A material forming a light-shielding film and a capacitor lower electrode is formed on a substrate, a photoresist is formed on a material forming a light-shielding film and a capacitor lower electrode, and the light-shielding film and the capacitor are formed by using the photoresist as an etching mask. The step of etching the material to be the lower electrode to form the light-shielding film and the capacitor lower electrode, forming the interlayer insulating film, the source / drain electrode material and the intermediate film on the interlayer insulating film, and the photoresist on the intermediate film. Is formed, the photoresist is used as an etching mask to etch the intermediate film and the source / drain electrode material to the middle of the film thickness, the photoresist is ashed, and the source / drain electrode material is etched using the photoresist as an etching mask. To form a source / drain electrode, and a semiconductor film material, a gate insulating film material, and a gate electrode material are sequentially formed. A step of forming a photoresist on the gate electrode material, and using the photoresist as an etching mask to etch the semiconductor film material, the gate insulating film material, and the gate electrode material to form the semiconductor film, the gate insulating film, and the gate electrode. And a step of forming the thin film transistor. 35. A material forming a light-shielding film and a capacitor lower electrode is formed on a substrate, a photoresist is formed on a material forming a light-shielding film and a capacitor lower electrode, and the light-shielding film and the capacitor are formed by using the photoresist as an etching mask. The step of forming a light-shielding film and a capacitor lower electrode by etching the material for the lower electrode, forming an oxide film on the capacitor lower electrode, and forming an interlayer insulating film, and forming a source / drain electrode material on the interlayer insulating film. Then, a photoresist is formed on the source / drain electrode material, the photoresist is used as an etching mask to etch to the middle of the thickness of the source / drain electrode material, the photoresist is ashed, and the photoresist is used as an etching mask. Etching the source / drain electrode material to form the source / drain electrode, and the semiconductor film material and the gate insulating film material. And a gate electrode material are sequentially formed, and a photoresist is formed on the gate electrode material, and the semiconductor film material, the gate insulating film material, and the gate electrode material are etched by using the photoresist as an etching mask to form a semiconductor. A method of manufacturing a thin film transistor, comprising the steps of forming a film, a gate insulating film, and a gate electrode. 36. A material for a light-shielding film and a capacitor lower electrode is formed on a substrate, a photoresist is formed on a material for a light-shielding film and a capacitor lower electrode, and the light-shielding film and the capacitor are formed by using the photoresist as an etching mask. A step of forming a light-shielding film and a capacitor lower electrode by etching a material to be a lower electrode, forming an oxide film on the capacitor lower electrode, and forming an interlayer insulating film, and a step of forming a source drain electrode material and an intermediate layer on the interlayer insulating film. A film is formed, a photoresist is formed on the intermediate film, the photoresist is used as an etching mask, the intermediate film and the source / drain electrode material are etched to the middle of the film thickness, the photoresist is ashed, and the photoresist is further removed. A step of etching the source / drain electrode material using the etching mask to form the source / drain electrode; a semiconductor film material and a gate insulating film material And a gate electrode material are sequentially formed, and a photoresist is formed on the gate electrode material, and the semiconductor film material, the gate insulating film material, and the gate electrode material are etched by using the photoresist as an etching mask to form a semiconductor. A method of manufacturing a thin film transistor, comprising the steps of forming a film, a gate insulating film, and a gate electrode. 37. A material forming a light-shielding film and a capacitor lower electrode is formed on a substrate, a photoresist is formed on a material forming a light-shielding film and a capacitor lower electrode, and the light-shielding film and the capacitor are formed by using the photoresist as an etching mask. The step of forming a light-shielding film and a capacitor lower electrode by etching the material to be the lower electrode, forming an interlayer insulating film, forming a source / drain electrode material on the interlayer insulating film, and applying a photoresist on the source / drain electrode material. The photoresist is used as an etching mask to etch the source / drain electrode material up to the middle of the film thickness, the photoresist is heat-treated to be softened, and the photoresist is used as an etching mask to etch the source / drain electrode material. Forming a source / drain electrode, a semiconductor film material, a gate insulating film material, and a gate electrode material are sequentially formed. And forming a photoresist on the gate electrode material, and etching the semiconductor film material, the gate insulating film material, and the gate electrode material using the photoresist as an etching mask to form the semiconductor film, the gate insulating film, and the gate electrode. And a step of forming a thin film transistor. 38. A material forming a light-shielding film and a capacitor lower electrode is formed on a substrate, a photoresist is formed on a material forming a light-shielding film and a capacitor lower electrode, and the light-shielding film and the capacitor are formed by using the photoresist as an etching mask. A step of etching a material to be a lower electrode to form a light shielding film and a capacitor lower electrode, and forming an interlayer insulating film, and forming a source / drain electrode material on the interlayer insulating film, and forming a first drain / source electrode material on the interlayer insulating film. Forming a photoresist, etching the source / drain electrode material using the photoresist as an etching mask,
Is removed, and a second photoresist having a smaller pattern size than the first photoresist is formed on the source / drain electrode material, and the second photoresist is used as an etching mask to form a film of the source / drain electrode material. A step of forming a source / drain electrode by etching to the middle of the thickness; a step of sequentially forming a semiconductor film material, a gate insulating film material, and a gate electrode material, and forming a photoresist on the gate electrode material; A method of manufacturing a thin film transistor, comprising: a step of etching a semiconductor film material, a gate insulating film material, and a gate electrode material using an etching mask to form a semiconductor film, a gate insulating film, and a gate electrode. 39. A material for a light-shielding film and a capacitor lower electrode is formed on a substrate, a photoresist is formed on a material for a light-shielding film and a capacitor lower electrode, and the light-shielding film and the capacitor are formed by using the photoresist as an etching mask. A step of etching a material to be a lower electrode to form a light shielding film and a capacitor lower electrode, and forming an interlayer insulating film, and forming a source / drain electrode material on the interlayer insulating film, and forming a first drain / source electrode material on the interlayer insulating film. A photoresist is formed, the source / drain electrode material is etched to the middle of the film thickness by using the photoresist as an etching mask, the first photoresist is removed, and the source / drain electrode material is smaller than the first photoresist. Forming a second photoresist having a pattern size,
The step of etching the source / drain electrode material by using the photoresist as an etching mask to form the source / drain electrode, the semiconductor film material, the gate insulating film material, and the gate electrode material are sequentially formed, and the photoresist is formed on the gate electrode material. And a step of forming a semiconductor film, a gate insulating film, and a gate electrode by etching the semiconductor film material, the gate insulating film material, and the gate electrode material using a photoresist as an etching mask. A method of manufacturing a thin film transistor, comprising: 40. A material forming a light-shielding film and a capacitor lower electrode is formed on a substrate, a photoresist is formed on a material forming a light-shielding film and a capacitor lower electrode, and the light-shielding film and the capacitor are formed by using the photoresist as an etching mask. A step of etching a material to be a lower electrode to form a light shielding film and a capacitor lower electrode, and forming an interlayer insulating film, and forming a source / drain electrode material on the interlayer insulating film, and forming a first drain / source electrode material on the interlayer insulating film. A photoresist is formed, the first photoresist is used as an etching mask to etch the source / drain electrode material up to the middle of the film thickness, the first photoresist is removed, and the first photoresist on the source / drain electrode material is removed. A source / drain electrode material is formed by forming a second photoresist having a pattern size larger than that of the resist and using the second photoresist as an etching mask. Material to form a source / drain electrode, a semiconductor film material, a gate insulating film material, and a gate electrode material are sequentially formed, and a photoresist is formed on the gate electrode material; and a photoresist is used as an etching mask. And a step of etching the semiconductor film material, the gate insulating film material, and the gate electrode material to form the semiconductor film, the gate insulating film, and the gate electrode.