CN202523718U

CN202523718U - Structure of thin film transistor

Info

Publication number: CN202523718U
Application number: CN2012201248138U
Authority: CN
Inventors: 吕建国; 张�杰; 李喜峰; 叶志镇; 张焱; 吴萍
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2012-03-29
Filing date: 2012-03-29
Publication date: 2012-11-07
Anticipated expiration: 2022-03-29

Abstract

The utility model provides a structure of a thin film transistor, which comprises a grid, an insulating layer and an active layer arranged successively from bottom to top. A source electrode and a drain electrode are covered on the active layer and at a distance from each other. The grid is in an "n" shape. The width of a device channel is equal to the width of the bottom edge of the "n" shape. The widths of the source electrode and the drain electrode in the channel are greater than the width of the bottom edge of the "n" shape. The length of the device channel is equal to a distance between the source electrode and the drain electrode. The structure of the thin film transistor adopts an "n"-shaped grid and the width of the bottom edge of the "n" shape defines the width of the device channel. Meanwhile, the grid and the patterns of the source electrode and the drain electrode are completed in a two-step lithography manner. Due to the adoption of the structure, the process difficulty that the lithography of the patterns of the source electrode and the drain electrode is performed simultaneously during controlling the length and the width of the device channel is overcome. Thus, the structure is beneficial to improve the device yield.

Description

A kind of structure of thin-film transistor

Technical field

The utility model relates to a kind of structure of thin-film transistor.

Background technology

Thin-film transistor technologies has been the dominant technology of flat panel display now.In flat-panel display device, introduce thin-film transistor (TFT) switch element and storage capacitance, can improve the display device performance greatly, realize that the video of big capacity, high definition and full color shows.At present; The thin-film transistor that is applied in the display has grid, insulating barrier, active layer from bottom to top successively, on active layer, covers the source electrode and the drain electrode of being separated by; Grid is rectangle plane (like Fig. 1); The length L of thin film transistor channel is to define through the distance of being separated by between source electrode and the drain electrode, and the width W of raceway groove is that the width through device channel place source electrode or drain electrode defines.Source, drain electrode figure are realized through a step photoetching process; The length and the width that are raceway groove are also confirmed through this step photoetching process; The raising that Along with people's requires monitor resolution, the integrated level of thin-film transistor requires corresponding raising, and device size comprises that the length of its raceway groove and width also require proportional dwindling; Yet control channel length and proportional dwindling of width while through photolithographic source, drain electrode figure; With the difficulty that increases photoetching process, in case this step process go wrong, with the rate of finished products that has a strong impact on device.

Summary of the invention

The purpose of the utility model provides a kind of thin-film transistor structure that helps improving device yield.

The thin-film transistor structure of the utility model; Grid, insulating barrier, active layer are arranged from bottom to top successively, on active layer, be coated with the source electrode and the drain electrode of being separated by; The length of device channel equals the distance of being separated by between source electrode and the drain electrode; Grid is " n " type shape, and the width of device channel equals the hem width on " n " type base, and the width of raceway groove place source electrode and drain electrode is greater than the width on " n " type base.

The thin-film transistor structure of the utility model; Because the grid of " n " type of employing shape; Define the width of device channel by the hem width on " n " type base; Grid and source, drain electrode pattern are accomplished through two step photoetching, have overcome the technology difficulty of being controlled channel length and width by photolithographic source, drain electrode pattern simultaneously, help improving device yield.

Description of drawings

Fig. 1 is the structure vertical view of conventional thin film transistor;

The structure vertical view of the thin-film transistor of Fig. 2 the utility model;

Fig. 3 is the A-A profile of Fig. 2.

Among the figure, 1 is grid.2 is insulating barrier, and 3 is active layer, and 4 is source electrode, and 5 are drain electrode, and L is a channel length, and W is a channel width.

Embodiment

Further specify the utility model below in conjunction with accompanying drawing.

With reference to Fig. 2 and Fig. 3; The structure of the thin-film transistor of the utility model; Grid 1, insulating barrier 2, active layer 3 are arranged from bottom to top successively, on active layer 3, be coated with the source electrode 4 and the drain electrode 5 of being separated by, grid 1 is " n " type shape, and the width W of device channel equals the hem width on " n " type base; The width W that is device channel is defined by the hem width on " n " type base; The width of raceway groove place source electrode 4 and drain electrode 5 is greater than the width on " n " type base, and the length L of device channel equals the distance of being separated by between source electrode 4 and the drain electrode 5, and promptly the length L of device channel is defined by distance between source electrode 4 and the drain electrode 5.

Claims

1. the structure of a thin-film transistor; Grid (1), insulating barrier (2), active layer (3) are arranged from bottom to top successively, on active layer (3), be coated with the source electrode (4) and the drain electrode (5) of being separated by; The length of device channel (L) equals the distance of being separated by between source electrode (4) and the drain electrode (5); It is characterized in that grid (1) is " n " type shape; The width of device channel (W) equals the hem width on " n " type base, and the width of raceway groove place source electrode (4) and drain electrode (5) is greater than the width on " n " type base.