CN100428039C

CN100428039C - A TFT LCD pixel structure

Info

Publication number: CN100428039C
Application number: CNB2005101150350A
Authority: CN
Inventors: 高文宝
Original assignee: BOE Technology Group Co Ltd; Beijing BOE Optoelectronics Technology Co Ltd
Current assignee: BOE Technology Group Co Ltd; Beijing BOE Optoelectronics Technology Co Ltd
Priority date: 2005-11-23
Filing date: 2005-11-23
Publication date: 2008-10-22
Anticipated expiration: 2025-11-23
Also published as: CN1971390A

Abstract

A TFT LCD pixel construction is disclosed, the ring or polygonal TFT component is designed to gate, the via hole part of the pixel is also designed to the gate, the design can increase the W/L of the channel in condition of non-reducing the opening ratio, and increase the on-state current (Ion), the most important is it can limit the post stool (PS) adopted by current color filter.

Description

A kind of TFT LCD dot structure

Technical field

The invention belongs to TFT LCD dot structure design aspect, mainly is the design of TFT device architecture.

Background technology

The structural design as shown in Figure 1 of the most of employing of the TFT LCD dot structure that adopts at present:

Be connected by via hole (via hole) between the pixel electrode of TFT (ITO) and the source electrode (source), and the via hole part does not design on grid lead (gate).Therefore:

1, the design of this kind dot structure is considering that whether fully the charging of aperture opening ratio and pixel during these two contrarieties, needs both relations of balance.In the design of large-size device, wish breadth length ratio (W/L) is increased, better to satisfy the charge rate requirement, will increase the width of conducting channel (channel) like this, increased the size of TFT, reduced the aperture opening ratio of device.

2, this kind structural design is complicated, needs the factor of consideration more.

3, what is more important is based on the design of this kind TFT device architecture, the form that is positioned on the TFT with the column shaped spacer (PS) of color film (CF) is an example, exist column shaped spacer (PS) to sustain damage easily, form the bad problems such as (mura) of box thick (Gap) property picture.

The upper end size (top size) of column shaped spacer (PS) is less than lower end size (bottom size) in the general design, be approximately trapezoidal conical structure, after to box technology, there is certain moving range column shaped spacer (PS) upper end, shown in round zone among Fig. 2, be subjected to external force on the panel surface and do the time spent, color membrane substrates is easy to produce with respect to array base palte and moves, simultaneously because the surface of contact of column shaped spacer (PS) and TFT on the rib ridge of source-drain electrode (S/D), the unevenness on surface causes the damage of column shaped spacer (PS) upper surface easily, simultaneously because both are not the face contacts, the pressure that contact jaw bore will be very big, this also may cause the damage of TFT pixel electrode (ITO), as shown in Figure 3.

4, simultaneously, this kind design can not well limit column shaped spacer (PS) upper end moving on array base palte (array), under the effect of external force, color film (CF) mobile slightly is if surpass the upper limit of box specification then may cause white picture bad (white mura) or an array of stars shape (zaratsuki) property light leakage phenomena.

Summary of the invention

The objective of the invention is under the situation that does not reduce aperture opening ratio, to increase the breadth length ratio of raceway groove, improve ON state current.

Another object of the present invention is to play the restriction column shaped spacer equally to move under the condition that does not change the panel surface holding capacity, and then the restriction color membrane substrates moves.

For achieving the above object, the invention provides a kind of TFT LCD dot structure, comprise glass substrate, be formed at the TFT device on the glass substrate, it is characterized in that: the TFT device portions all is formed on the grid lead.Wherein said TFT device portions comprise and grid lead be one circular grid, be formed at circular active layer on the grid, be formed at two annular source-drain electrodes on the active layer, be formed at annular conducting channel between the source-drain electrode, be formed at source-drain electrode and the passivation layer of conducting channel top, the circular via hole that on passivation layer, forms, pixel electrode links to each other with source electrode by circular via hole.Above-mentioned TFT device portions also can be comprise and grid lead be one the polygon grid, be formed at polygon active layer on the grid, be formed at two polygon annular source drain electrode on the active layer, be formed at polygon annular conducting channel between the source-drain electrode, be formed at passivation layer, the circle that on passivation layer, forms or the polygon via hole of source-drain electrode and conducting channel top, pixel electrode links to each other with source electrode by circle or polygon via hole.

In addition, for the restriction that further reduces stray capacitance and strengthen column shaped spacer is moved, partly form the structure of hollow at the bottom gate of TFT device architecture, wherein hollow structure is shaped as circle or the polygon suitable with via hole.

Moreover, under the step effect that forms jointly by source-drain electrode and passivation layer, cause the pixel electrode broken string for fear of pixel electrode and via hole coupling part, on the active layer of TFT device with pixel electrode lap-joint drain electrode formation opening.

The present invention overcomes the defective that has aperture opening ratio and two contradictory factors of pixel charging in the prior art, by with annular or polygonal TFT designs to grid line, realization can increase the breadth length ratio of raceway groove under the situation that does not reduce aperture opening ratio, improve ON state current, the most important thing is the via hole of pixel part also is designed into method on the grid line, can play certain restriction the column shaped spacer that present color film adopted.

Below in conjunction with description of drawings and embodiment the aspect is elaborated.

Description of drawings

Fig. 1 is the TFT structural design that adopts usually;

Fig. 2 is the vertical view of the moving range of column shaped spacer (PS) upper end;

Fig. 3 is the outboard profile of the moving range (is example on TFT with PS) of column shaped spacer (PS) upper end;

Fig. 4 and Fig. 4 A are circular TFT structural design of the present invention and schematic cross-section;

Fig. 5 and Fig. 5 A are the vertical view and the sectional view (is example on TFT with PS) of column shaped spacer of the present invention (PS) upper end moving range, and the rounded valleys that can see the formation of via portion branch is to column shaped spacer (PS) restriction;

The another kind of structure that Fig. 6 and Fig. 6 A derive for the present invention, grid line partly are the design and the sectional view of hollow structure;

The another kind of structure that Fig. 7 and Fig. 7 A derive for the present invention, design and the sectional view locating to make a breach near pixel electrode (ITO) at source-drain electrode (S/D).

Identify among the figure: 1, gate electrode (gate); 2, active layer (active); 3, source-drain electrode (S/D); 4, via hole (via hole); 5, pixel electrode (ITO); 6, glass substrate (glass); 7, column shaped spacer (PS); 8, color film (CF); 9, conducting channel (channel); 10, passivation layer (PVX).

Embodiment

Embodiment 1

Shown in Fig. 4 and Fig. 4 A.At first on glass substrate 6, form grid lead, wherein gate electrode 1 is an one with grid lead, gate electrode 1 is circular, on gate electrode 1, form the active layer 2 of circular configuration by technologies such as photoetching, on active layer 2, form the source-drain electrode 3 of two annulars, be formed at the annular conducting channel 9 between the source-drain electrode 3; Be formed at the passivation layer 10 of source-drain electrode 3 and conducting channel 9 tops; Be formed at the circular via hole 4 of source electrode contact on passivation layer 10, pixel electrode 5 links to each other with the source terminal of source-drain electrode 3 by circular via hole 4, and after last pixel electrode 5 technologies were finished, having formed center section was the device architecture on a plane.

By the circular TFT structural design of Fig. 4 and Fig. 4 A, can when guaranteeing aperture opening ratio, increase the breadth length ratio of conducting channel 9, otherwise consideration can be when guaranteeing breadth length ratio, the whole TFT device portions of scaled down increases aperture opening ratio.TFT device each several part size is under the prerequisite that takes into full account the fabrication error scope, and minification as much as possible is to increase aperture opening ratio.

Shown in Fig. 5 and Fig. 5 A, in this patent, column shaped spacer 7 can move in certain scope, and the surface of contact of mobile terminal is a planar structure.The consideration of moving in addition based on restriction column shaped spacer 7 upper ends, also can be according to the designing requirement of the size of circular via hole 4, adjust the density of column shaped spacer 7 sizes and column shaped spacer 7, under the condition that does not change the panel surface holding capacity, play restriction column shaped spacer 7 equally and move, and then limit the effect that color membrane substrates 8 moves.

By finding out among Fig. 5 and Fig. 5 A, the passivation layer 10 of via hole 4 parts has formed annular paddy structure through photoetching process, can limit column shaped spacer 7 upper ends moving in annular paddy, the stressed end face of column shaped spacer 7 is the plane simultaneously, can reduce column shaped spacer 7 damages.

Implementation method as the present embodiment accommodation is that the shape of the active layer 2 that forms on it, source-drain electrode 3, the shape that reaches conducting channel 9 and gate electrode 1 is suitable, for circle also can be polygon with the shaped design one-tenth rule or the irregular polygon of gate electrode 1.Shape of via hole 4 is preferably circular on it, also can be the polygon suitable with column shaped spacer 7.

Embodiment 2

Shown in Fig. 6 and Fig. 6 A.Considering to reduce under the situation of stray capacitance, can form hollow structure in bottom gate electrode 1 part of embodiment 1 described TFT device architecture, be beneficial to reduce the stray capacitance between the grid source, can increase the degree of depth of annular paddy simultaneously, strengthen the restriction that column shaped spacer 7 is moved.Wherein, it is circular that the shape of hollow structure is preferably, and also can be polygon, and suitable with column shaped spacer 7 upper ends.

Embodiment 3

Shown in Fig. 7 and Fig. 7 A.Under the step effect that forms jointly by source-drain electrode 3 and passivation layer 10, cause pixel electrode 5 broken strings for fear of pixel electrode 5 and via hole 4 coupling parts, can be in embodiment 1 or embodiment 2 described TFT devices, on the basis of sacrificial section breadth length ratio, source-drain electrode 3 annulars are made a breach, form smooth surface of contact.

More than explanation and accompanying drawing illustrate specific implementations of the present invention, but self-evident, the present invention can carry out various distortion by those skilled in the art and implement, as the shape of conversion TFT device, conversion bottom gate hollow structure shape etc.The embodiment that has been out of shape like that etc. can not break away from technological thought of the present invention or prospect is individually understood, and must regard the structure and the method for making that comprise in the appending claims of the present invention as.

Claims

1, a kind of TFT LCD dot structure, comprise glass substrate, be formed at the TFT device on the glass substrate, the TFT device portions all is formed on the grid lead, it is characterized in that: described TFT device portions comprises with grid lead being the circular grid of one, be formed at the circular active layer on the grid, be formed at the two annular source-drain electrodes on the active layer, be formed at the annular conducting channel between the source-drain electrode, be formed at the passivation layer of source-drain electrode and conducting channel top, the circular via hole that forms on passivation layer, pixel electrode links to each other with source electrode by circular via hole.

2, a kind of TFT LCD dot structure according to claim 1, it is characterized in that: described TFT device portions partly forms the structure of hollow at the bottom gate of TFT device architecture.

3, a kind of TFT LCD dot structure according to claim 2 is characterized in that: the hollow structure of the bottom gate part of described TFT device portions is shaped as circle or the polygon suitable with via hole.

4, a kind of TFT LCD dot structure, comprise glass substrate, be formed at the TFT device on the glass substrate, the TFT device portions all is formed at grid lead and it is characterized in that: described TFT device portions comprises with grid lead being the polygon grid of one, be formed at the polygon active layer on the grid, be formed at the two polygon annular source drain electrode on the active layer, be formed at the polygon annular conducting channel between the source-drain electrode, be formed at the passivation layer of source-drain electrode and conducting channel top, circle that forms on passivation layer or polygon via hole, pixel electrode links to each other with source electrode by circle or polygon via hole.

5, a kind of TFT LCD dot structure according to claim 4, it is characterized in that: described TFT device portions partly forms the structure of hollow at the bottom gate of TFT device architecture.

6, a kind of TFT LCD dot structure according to claim 5 is characterized in that: the hollow structure of the bottom gate part of described TFT device portions is shaped as circle or the polygon suitable with via hole.

7, a kind of TFT LCD dot structure, comprise glass substrate, be formed at the TFT device on the glass substrate, the TFT device portions all is formed on the grid lead and it is characterized in that: described TFT device portions comprise and grid lead be one circular grid, be formed at circular active layer on the grid, be formed on the active layer and the drain electrode of pixel electrode lap-joint have opening two annular source-drain electrodes, be formed at annular conducting channel between the source-drain electrode, be formed at the passivation layer above source-drain electrode and the conducting channel, the circular via hole that on passivation layer, forms; Pixel electrode links to each other with source electrode by circular via hole.

8, a kind of TFT LCD dot structure according to claim 7, it is characterized in that: described TFT device portions partly forms the structure of hollow at the bottom gate of TFT device architecture.

9, a kind of TFT LCD dot structure according to claim 8 is characterized in that: the hollow structure of the bottom gate part of described TFT device portions is shaped as circle or the polygon suitable with via hole.

10, a kind of TFT LCD dot structure, comprise glass substrate, be formed at the TFT device on the glass substrate, it is characterized in that: described TFT device portions comprises and the polygon grid of grid lead one, be formed at polygon active layer on the grid, be formed on the active layer and the drain electrode of pixel electrode lap-joint have opening two polygon annular source drain electrode, be formed at polygon annular conducting channel between the source-drain electrode, be formed at passivation layer, the circle that on passivation layer, forms or polygon via hole above source-drain electrode and the conducting channel; Pixel electrode links to each other with source electrode by circle or polygon via hole.

11, a kind of TFT LCD dot structure according to claim 10, it is characterized in that: described TFT device portions partly forms the structure of hollow at the bottom gate of TFT device architecture.

12, a kind of TFT LCD dot structure according to claim 11 is characterized in that: the hollow structure of the bottom gate part of described TFT device portions is shaped as circle or the polygon suitable with via hole.