CN101047145A

CN101047145A - Method for preparing metal wire in active drive TFT matrix

Info

Publication number: CN101047145A
Application number: CN 200610066420
Authority: CN
Inventors: 王章涛; 邱海军; 陈旭; 闵泰烨; 林承武
Original assignee: BOE Technology Group Co Ltd
Current assignee: BOE Technology Group Co Ltd
Priority date: 2006-03-30
Filing date: 2006-03-30
Publication date: 2007-10-03

Abstract

The present invention provides a method for preparing metal connecting wire in active drive TFT matrix. Said method includes the following steps: firstly, uniformly coating a layer of negative photoresist on a substrate, making exposure and developing to make the remained negative photoresis have inverted trapezoidal-shaped cross section; then on the substrate and negative photoresist continuously dopositing required metal layer, finally, adopting chemical solution to remove negative photoresist on the substrate, at the same time removing metal layer on said negative photoresist, so that the required metal connecting wire can be remained.

Description

A kind of method for preparing metal connecting line in the active driving TFT matrix

Technical field

This patent relates to a kind of manufacturing process of active driving TFT matrix, particularly based on the preparation method of metal connecting line in a kind of TFT matrix.

Background technology

Along with the continuous increase of LCD Panel, the continuous increase of display pixel, the metal material of high resistivity can't satisfy the requirement that the TFT matrix signal postpones.Therefore, have the metal of low resistivity such as the first-selection that Al, Cu etc. become the TFT metal electrode material.But also there are many shortcomings in pure Al and pure Cu as electrode material, the one, and poor heat stability is easy to generate serious hillock phenomenon as Al film its surface after high-temperature process; The 2nd, poor chemical stability, the surface is oxidation or corrosion easily.In order to overcome these shortcomings, using more electrode material in large-screen, high-resolution liquid crystal display screen is bilayer or the sandwich construction of Al and refractory metal Cr, Mo etc.But the metal level of this bilayer or sandwich construction also can bring new problem in the process of wet etching.When the metal of two or more different electrode potentials is in corrosive medium and is in contact with one another, will cause Jia Fanni (Galvanic) electrochemical corrosion, metal such as Al that electrode potential is lower serve as anode, lose electronics, and higher metal such as the Mo of electrode potential serves as negative electrode, obtains electronics.Therefore, anode metal is understood accelerated corrosion usually, and cathodic metal then can slow down corrosion, thereby makes the cross sectional shape of this bilayer or sandwich construction metal level be trapezoidal, is unfavorable for the deposition of subsequent gate insulating barrier.

In order to address this problem, a kind of technology based on twice wet etching grows up gradually, its basic craft course is as follows: at first successive sedimentation ground floor metal 12 (as Mo) and second layer metal 13 (as AlNd) on transparent glass substrate or quartzy 11, shown in Fig. 1 .1, then form positive photoresist 14 figures, as Fig. 1 .2 by traditional photoetching technique.After the photoetching, in the mixed solution of phosphoric acid, nitric acid and acetic acid, carry out the wet etching first time.Because Jia Fanni electrochemical corrosion effect, it is fast that the etch ratio Mo of Al wants, and therefore forms the trapezoid cross section of falling shown in Fig. 1 .3.Then at H ₂O ₂Or carry out the wet etching second time in the C.A.N solution.In these two kinds of solution, the corrosion rate of Mo is very fast, and Al does not corrode basically, and therefore the trapezoid cross section is changed the trapezoid cross section into, as Fig. 1 .4.Carry out peeling off of photoresist at last, obtained having the metal line pattern of trapezoid cross section, as Fig. 1 .5.

Though this method can access the metal line pattern with trapezoid cross section, because it has adopted wet corrosion technique twice, consumed a large amount of chemical solutions, increased the production cost of TFT matrix, increased the production cycle of product simultaneously.

Summary of the invention

The objective of the invention is at the deficiencies in the prior art, a kind of method for preparing metal connecting line in the active driving TFT matrix is provided, good trapezium structure is arranged, be convenient to the deposition of follow-up other layer with the cross sectional shape of the metal wire that obtains.

To achieve these goals, the invention provides a kind of method for preparing metal connecting line in the active driving TFT matrix, it is characterized in that: comprise the steps, at first, on substrate, evenly apply the last layer negative photoresist, by exposure imaging, make the negative photoresist that remains that trapezoidal cross section be arranged down; Then, the needed metal level of successive sedimentation in substrate and negativity photoetching; At last, adopt chemical solution that the negative photoresist on the substrate is removed, metal level in the above is removed simultaneously, and needed metal connecting line is retained, and its cross section is trapezoidal.

Wherein, described substrate is transparent glass substrate, quartz or other dielectric layer according to the metal connecting line of making.Described successive sedimentation metal level can be one deck, two-layer or sandwich construction.Described metal level can be selected Cr, W, Ti, Ta, Mo, Al, Cu or its alloy for use.The metal connecting line of making by above-mentioned steps can be gate electrode or grid line, also can be source-drain electrode or data wire.

Metal connecting line formation method---wet etching is compared with traditional in the present invention, the present invention has two tangible advantages: the one, and the preparation method who forms metal connecting line is simple, production cycle is shortened effectively, formed metal connecting line has good cross sectional shape simultaneously, be convenient to the deposition of follow-up other layer, help the raising of rate of finished products; The 2nd, can save the chemical solution that is used for wet etching in a large number, as phosphoric acid, nitric acid and acetic acid etc., reduced the difficulty of liquid waste processing, reduce the production cost of TFT matrix effectively.

Below by drawings and Examples, technical scheme of the present invention is described in further detail.

Description of drawings

Fig. 1 .1 is the sectional view after glass substrate carries out the successive sedimentation double layer of metal;

Fig. 1 .2 is the sectional view after exposure and the development;

Fig. 1 .3 is the sectional view behind the wet etching first time;

Fig. 1 .4 is the sectional view behind the wet etching second time;

Fig. 1 .5 is the sectional view behind the stripping photoresist;

Fig. 2 .1 is the sectional view of the present invention after negative photoresist exposure and development;

Fig. 2 .2 is a sectional view of the present invention after successive sedimentation double layer of metal on glass substrate and the negative photoresist;

Fig. 2 .3 is that negative photoresist is peeled off back sectional view of the present invention;

Fig. 3 .1 is the sectional view of the present invention after the active layer figure forms back negative photoresist exposure and develops;

Fig. 3 .2 is a sectional view of the present invention after deposition layer of metal on active layer and the negative photoresist;

Fig. 3 .3 forms sectional view of the present invention behind the source-drain electrode for peeling off through negative photoresist;

Identify among the figure: 11, transparent glass substrate or quartz; 12, ground floor metal; 13, second layer metal; 14, positive photoresist; 15, negative photoresist; 16, gate insulation layer; 17, active layer; 18, source-drain electrode

Embodiment

Embodiment one:

Fig. 2 .1, Fig. 2 .2, Fig. 2 .3 show the process of utilizing the present invention to prepare grid line in the TFT matrix metal connecting line or gate electrode.

At first, on transparent glass substrate or quartzy 11, evenly apply last layer negative photoresist 15, exposure, stoving temperature and developing time etc. when the thickness by rational adjustment negative photoresist, composition and exposure, make the negative photoresist that remains that trapezoidal cross section be arranged down, as Fig. 2 .1.

Then, adopt method successive sedimentation metal level on transparent glass substrate or quartzy and negative photoresist 15 of sputter or thermal evaporation, the successive sedimentation metal level can be one deck, two-layer or sandwich construction according to the needs of metal connecting line, and metal can be selected metal or its alloys such as Cr, W, Ti, Ta, Mo, Al, Cu for use.Specific to present embodiment, the metal level of successive sedimentation is two-layer, and wherein ground floor metal level 12 is about 100～3000  of thickness, and second layer metal layer 13 is about 100～3000  of thickness, as Fig. 2 .2.

At last, chemical solutions such as employing IPA are removed the negative photoresist on transparent glass substrate or quartzy 11 15, and double layer of metal in the above is removed simultaneously, and needed metal connecting line is retained, and its cross section is trapezoidal, as Fig. 2 .3.By the grid line and the gate electrode of above-mentioned steps preparation,, help the deposition of subsequent gate insulating barrier because the cross section is trapezoidal.

Embodiment two:

Equally, can utilize above-mentioned similar processing step, other metal connecting lines in the preparation TFT matrix metal connecting line are as source-drain electrode or data wire.

Fig. 3 .1, Fig. 3 .2, Fig. 3 .3 show the process of utilizing the present invention to prepare source-drain electrode in the TFT matrix metal connecting line or data wire.

At first, on transparent glass substrate or quartzy 11, form grid metal electrode (ground floor metal 12, second layer metal 13), behind gate insulation layer 16 and the active layer 17 (comprising the n+ layer), evenly apply last layer negative photoresist 15, exposure, stoving temperature and developing time etc. when the thickness by rational adjustment negative photoresist, composition and exposure, make the negative photoresist that remains that trapezoidal cross section be arranged down, as Fig. 3 .1.

Then, adopt method successive sedimentation metal level on active layer 17 and negative photoresist 15 of sputter or thermal evaporation, the successive sedimentation metal level can be one deck, two-layer or sandwich construction according to the needs of metal connecting line, and metal can be selected metal or its alloys such as Cr, W, Ti, Ta, Mo, Al, Cu for use.Specific to present embodiment, the metal level of successive sedimentation is one deck, and about 100～3000  of its thickness are as Fig. 3 .2.

At last, chemical solutions such as employing IPA are removed the negative photoresist on the active layer 17 15, and metal in the above is removed simultaneously, and needed metal connecting line is retained, and its cross section is trapezoidal, as Fig. 3 .3.By the data wire and the source-drain electrode 18 of above-mentioned steps preparation,, help the deposition of follow-up passivation layer because the cross section is trapezoidal.

It should be noted that at last, above embodiment is only unrestricted in order to technical scheme of the present invention to be described, although the present invention is had been described in detail with reference to preferred embodiment, those of ordinary skill in the art should can use different materials and equipment to realize it as required, promptly can make amendment or be equal to replacement, and not break away from the spirit and scope of technical solution of the present invention technical scheme of the present invention.

Claims

1, a kind of method for preparing metal connecting line in the active driving TFT matrix is characterized in that, comprises the steps:

At first, on substrate, evenly apply the last layer negative photoresist,, make the negative photoresist that remains that trapezoidal cross section be arranged down by exposure imaging;

Then, the needed metal level of successive sedimentation in substrate and negativity photoetching;

At last, adopt chemical solution that the negative photoresist on the substrate is removed, metal level in the above is removed simultaneously, and needed metal connecting line is retained, and its cross section is trapezoidal.

2, a kind of method for preparing metal connecting line in the active driving TFT matrix according to claim 1 is characterized in that: described successive sedimentation metal level can be one deck, two-layer or sandwich construction.

3, a kind of method for preparing metal connecting line in the active driving TFT matrix according to claim 1 is characterized in that: the metal connecting line that described step is made can be gate electrode or grid line, also can be source-drain electrode or data wire.

4, according to the arbitrary described a kind of method for preparing metal connecting line in the active driving TFT matrix of claim 1 to 3, it is characterized in that: described metal level can be selected Cr, W, Ti, Ta, Mo, Al, Cu or its alloy for use.