CN1870234B

CN1870234B - Manufacturing method of thin-film transistor

Info

Publication number: CN1870234B
Application number: CN2006100925506A
Authority: CN
Inventors: 石志鸿; 廖达文; 林汉涂; 甘丰源
Original assignee: AU Optronics Corp
Current assignee: AU Optronics Corp
Priority date: 2006-06-15
Filing date: 2006-06-15
Publication date: 2011-07-20
Anticipated expiration: 2026-06-15
Also published as: CN1870234A

Abstract

A method for preparing film transistor includes depositing a conductive layer on base plate then forming patternized mask on conductive layer to use said mask to cover region to form film transistor on base plate, removing off conductive layer region uncovered by said mask, defining laser hole in said mask by utilizing laser stripping means in order to expose partial conductive layer and making laser hole correspond to trench region for forming film transistor, etching exposed conductive layer to form drain electrode and source electrode at two sides of said trench.

Description

The manufacture method of thin-film transistor

Technical field

The present invention relates to a kind of manufacture method of thin film transistor (TFT) array, and particularly relate to the technology that a kind of technology of utilizing laser lift-off (laser ablation) is simplified thin film transistor (TFT) array.

Background technology

(Thin Film Transistor Liquid CrystalDisplay, manufacturing TFT-LCD) uses five road photo-marsk processes to make mostly for Thin Film Transistor-LCD at present.Five traditional road photo-marsk processes, shown in Fig. 1 (a): utilize physical vaporous deposition, deposition one deck the first metal layer on substrate 100 then, is removed unnecessary ground floor metal level zone with the first road photoetching etching, forms grid 120 on substrate 100.

Shown in Fig. 1 (b), successive sedimentation insulating barrier 140, semiconductor layer 160 and ohmic contact layer 180 are on grid 120 in regular turn, with the photoengraving carving technology of the second road photomask, form semiconductor layer 160 zones and ohmic contact layer 180 zones at thin-film transistor presumptive area T.

Shown in Fig. 1 (c), utilize physical vaporous deposition to plate second metal level in whole base plate 100, photoetching etched patternization second metal level and the ohmic contact layer under it 180 through the 3rd road photomask, form drain electrode 200a and source electrode 200b on thin-film transistor presumptive area T, and expose semiconductor layer 160 in the middle of drain electrode 200a and the source electrode 200b as channel region.

Shown in Fig. 1 (d), the existing structure of deposition protective layer 220 on the substrate 100 that comprises the island TFT regions through the photoengraving carving technology of the 4th road photomask, forms first contact hole 240 on source electrode 200b in protective layer 220.

Shown in Fig. 1 (e), pixel deposition electrode 260 is on protective layer 220, and the photoetching etched pattern pixel electrode 260 with the 5th road photomask is electrically connected at source electrode 200b through first contact hole 240.

In existing thin-film transistor manufacturing process, need use five road photomasks and finish whole technology, still, because the number of photomask is many more, can make that manufacturing cost improves, production capacity reduces, so reducing the photomask number and simplifying technology is the target that present industry is made joint efforts; And at present with utilizing laser-stripping method to simplify the way of technology, in the existing similar application of other application, please refer to US publication No. 20050064648, it utilizes the laser emission energy, heat energy is communicated to photo-thermal conversion coating (photothermal converting layer), make by the sublimation layer (sublimation layer) of top, the photo-thermal conversion coating zone of laser emission effect, therefore peel off, and US publication is to utilize laser-stripping method No. 20050258487, forms groove (groove) on the semiconductor layer in thin-film transistor.

Summary of the invention

Main purpose of the present invention is to provide a kind of simplification technology of thin-film transistor.

For reaching above-mentioned and other purpose, method of the present invention is mainly utilized laser lift-off, forms the laser hole on the patterning photoresist, reduces making of photomask and is used for reducing cost.

According to one embodiment of the present invention, this method comprises following key step: depositing conducting layer is on substrate, then, on conductive layer, form pattern mask, come the predetermined zone that forms thin-film transistor on the covered substrate, remove again and be not patterned the conductive layer that mask covers, next, utilize laser to divest legal adopted laser hole in pattern mask, come the conductive layer of exposed portions serve, and this laser hole is corresponding to the predetermined channel region that forms thin-film transistor; And, by the conductive layer that the laser hole is exposed, form drain electrode and source electrode along the etching of laser hole in the both sides of channel region.

For above and other objects of the present invention, feature and advantage can be become apparent, following conjunction with figs. and preferred embodiment are to illustrate in greater detail the present invention.

Description of drawings

Fig. 1 (a)～Fig. 1 (e) is a series of profiles, in order to existing flow process of making thin-film transistor to be described.

Fig. 2～10 are a series of profiles, in order to the flow process of explanation one embodiment of the present invention making thin-film transistor.

The simple symbol explanation

100～substrate; 120～grid;

140～insulating barrier; 160～semiconductor layer;

180～ohmic contact layer; 200a～drain electrode;

200b～source electrode; 220～protective layer;

240～the first contact holes; 260～pixel electrode;

300～substrate; 310～grid;

320～insulating barrier; 340～semiconductor layer;

360～ohmic contact layer; 380～conductive layer;

380a～drain electrode; 380b～source electrode;

400～photoresist layer; 420～protective layer;

440～pixel electrode; A～thin-film transistor presumptive area;

B～laser hole; C～predetermined channel district;

D～contact hole; T～thin-film transistor presumptive area.

Embodiment

Fig. 2 is the initial step of the preferred embodiment of the present invention: at first, form conductive layer on substrate 300, the deposition first photoresist layer (not shown) above conductive layer, utilize the exposure imaging of the first road photomask after, form grid 310 with etch process, remove the photoresist layer again.Wherein, this substrate 300 is the normal material that uses of general display such as the substrate of rigidity, for example: glass, pottery, silicon substrate etc., as be applied in flexible electronic product (flexible display) when going up, be flexible substrate, for example, plastic base, as polyether sulfone (polyethersulfone, PES), Polyethylene Naphthalate (polyethylenenaphthalate, PEN), polyethylene (Polyethylene, PE), polyimides (polyimide, PI), polyvinyl chloride (polyvinyl chloride, PVC), PETG (polyethylene terephthalate, the combination of material or above material such as PET), and, also can be the light transmissive material substrate, or not saturating material substrate, (electroluminescence light device ELD) or having mercy on property product (flexible display) field, can use the substrate of metal material for example to be used in electroluminescence element.

Next; successive sedimentation insulating barrier 320, semiconductor layer 340, ohmic contact layer 360, conductive layer 380 in regular turn; reach photoresist layer 400 as etch protection layer, behind the exposure imaging with the second road photomask, patterning photoresist layer 400; as shown in Figure 3; this photoresist layer 400 is covered in the conductive layer 380 on the thin-film transistor presumptive area A, then, and with anisotropic etching; remove the conductive layer that is not covered, as shown in Figure 4 by this patterning photoresist layer 400.Wherein, the material of semiconductor layer, ohmic contact regions can be the combination of amorphous silicon, polysilicon, microcrystal silicon, monocrystalline silicon or above-mentioned material, and ohmic contact layer can be Doped n-type or p type semiconductor layer.

Please refer to Fig. 5; utilize the energy of laser beam; carry out laser and divest method, divest partly photic resist layer 400, define laser hole B; to expose the conductive layer 380 of predetermined channel district C top; then, with isotropic etching or anisotropic etching, remove regional A ohmic contact layer 360 and semiconductor layer 340 in addition; this moment, the conductive layer 380 in the predetermined channel zone C can be used as protective layer, avoided ohmic contact layer and the etched removal of semiconductor layer under it.Structure after the etching as shown in Figure 6, it should be noted that this step also can carry out before divesting the laser hole B of legal adopted photoresist layer 400 carrying out laser; Next, the conductive layer 380 that exposes along laser hole B etching in regular turn and its ohmic contact layer 360 down are to form drain 380a and source electrode 380b in the both sides of channel region C, as Fig. 7.Remove photoresist layer 400 at last again, obtain structure shown in Figure 8.It should be noted that, prior art adopts the mode of photomask in this step, defines the pattern of photoresist layer 400, the present invention utilizes laser to divest the pattern that method defines photoresist layer 400, therefore can reduce the technology of one photomask and the cost of photomask.

In addition, embodiments of the invention also can utilize digit explosure mode (digital exposure), make laser beam locate and adjust the effect of energy automatically, carry out laser and divest, with the laser hole B of definition photoresist layer 400; In addition, divest in the process of method carrying out laser, also can use photomask to locate, to define the laser hole B of photoresist layer 400.

Following step, please refer to Fig. 9, deposition protective layer 420 is on second plain conductor 380, form photoresist layer (figure does not show) again on protective layer 420, after utilizing the exposure imaging of the 3rd road photomask, form contact hole D with etch process,, remove the photoresist layer at last again with the source electrode 380b of exposed portions serve; Next, continuation is pixel deposition electrode 440 above protective layer 420, form photoresist layer (not shown) again on pixel electrode 440, after utilizing the exposure imaging of the 4th road photomask, with etch process, allow this pixel electrode 440 be electrically connected through contact hole D and source electrode 380b, remove the photoresist layer again, as shown in figure 10; Wherein pixel electrode 440, can be through electrode or reflecting electrode according to type of display.The material of its printing opacity is for can be indium-zinc oxide (indium zinc oxide, IZO), indium tin oxide (indium tin oxide, ITO), cadmium tin-oxide (cadmium tin oxide, CTO), aluminium zinc oxide (aluminum zinc oxide, AZO) etc., and the reflection material for example metal be: gold, silver, copper, iron, aluminium, titanium, tantalum, molybdenum, neodymium, tungsten etc., the alloy of above-mentioned material or the combination of above-mentioned material; In addition, pixel electrode also can be the semi-penetration semi-reflective material, or is the above-mentioned combination that penetrates and reflect two kinds of materials, and the two is partly to cover; And second plain conductor 380 can be analogous to pixel electrode 440 with the material of grid 310.

Particularly, pixel electrode 440 provides voltage to luminescent material or liquid crystal material, and luminescent material also can be inorganic material, light-emitting diode (light emitting diode for example, LED), organic material can be electroluminescence element (electroluminescence light device, ELD) include OLED (organic light emitting diode, OLED) or polymer LED (polymer lightemitting diode PLED) waits organic material.

Laser process for stripping of the present invention, also can be used in the technological design of colored filter, for example thin-film transistor is formed on the colored filter, be called (the Array on color filter of array on the colored filter, AOC), or colored filter is formed on the thin-film transistor, is called array enamel filter (Colorfilter on array, design COA).

Though the present invention discloses as above with preferred embodiment; yet it is not in order to limit the present invention; those skilled in the art can do a little change and retouching without departing from the spirit and scope of the present invention, thus protection scope of the present invention should with claim the person of being defined be as the criterion.

Claims

1. the manufacture method of a thin-film transistor comprises:

Form conductive layer on substrate;

Form pattern mask on this conductive layer, to be covered in the zone of desire formation thin-film transistor on this substrate;

Remove not this conductive layer by this pattern mask covered;

Divest legal adopted laser hole in this pattern mask with laser, with this conductive layer of exposed portions serve, and this laser hole forms the channel region of this thin-film transistor corresponding to desire; And

This conductive layer that this laser hole of etching is exposed, with the drain electrode that forms this thin-film transistor and source electrode in the both sides of this channel region.

2. the manufacture method of thin-film transistor as claimed in claim 1 also is included in and forms grid, insulating barrier, semiconductor layer on this substrate in regular turn, wherein, this insulating barrier, be covered on this grid and this substrate, and this semiconductor layer is on this insulating barrier, and this conductive layer is on this semiconductor layer.

3. the manufacture method of thin-film transistor as claimed in claim 2 also comprises this semiconductor layer that removes not by this pattern mask covered.

4. the manufacture method of thin-film transistor as claimed in claim 2 wherein between this semiconductor layer and this conductive layer, also is provided with ohmic contact layer.

5. the manufacture method of thin-film transistor as claimed in claim 4 also comprises removing this ohmic contact layer that is not covered by this pattern mask.

6. the manufacture method of thin-film transistor as claimed in claim 4 also comprises this ohmic contact layer that this laser hole of etching is exposed.

7. the manufacture method of thin-film transistor as claimed in claim 1 also comprises the step of removing this pattern mask.

8. the manufacture method of thin-film transistor as claimed in claim 1 also comprises forming protective layer on this conductive layer.

9. the manufacture method of thin-film transistor as claimed in claim 8 also comprises forming pixel electrode on this protective layer.

10. the manufacture method of thin-film transistor as claimed in claim 9, wherein this pixel electrode provides voltage to luminescent material.

11. the manufacture method of thin-film transistor as claimed in claim 10, wherein this luminescent material comprises inorganic material or organic material.

12. the manufacture method of thin-film transistor as claimed in claim 1, wherein this substrate comprises flexible substrate, light tight substrate or transparent substrates.

13. the manufacture method of thin-film transistor as claimed in claim 12, wherein the material of flexible substrate comprises the combination of polyether sulfone, Polyethylene Naphthalate, polyethylene, polyimides, polyvinyl chloride, PETG or above material.

14. the manufacture method of thin-film transistor as claimed in claim 9, wherein the material of this pixel electrode comprises the material of printing opacity, the material of reflection or the combination of above-mentioned material.

15. the manufacture method of thin-film transistor as claimed in claim 1 also comprises forming colored filter on this substrate.

16. the manufacture method of thin-film transistor as claimed in claim 1 also comprises the formation colored filter, is covered in this thin-film transistor.