CN102184893A

CN102184893A - Process for manufacturing microcrystalline-silicon-based thin film resistor (TFT) active matrix

Info

Publication number: CN102184893A
Application number: CN201110096077XA
Authority: CN
Inventors: 李喜峰; 陈龙龙; 张建华
Original assignee: University of Shanghai for Science and Technology
Current assignee: University of Shanghai for Science and Technology
Priority date: 2011-04-18
Filing date: 2011-04-18
Publication date: 2011-09-14

Abstract

The invention discloses a process for manufacturing a microcrystalline-silicon-based thin film resistor (TFT) active matrix. The microcrystalline silicon serves as an active layer material of the TFT active matrix. The manufacturing process of the microcrystalline silicon is similar to the manufacturing process of amorphous silicon; the mobility of the microcrystalline silicon can be up to 2 to 10cm <2>.(V.S)-1 and is one magnitude more than that of the amorphous silicon material; and the mobility of the microcrystalline silicon manufactured by the process is up to 8.95 cm <2>.(V.S)-1. The synchronic microcrystalline silicon material is very stable and is more advantageous than the amorphous silicon material; and the production and manufacturing cost of the microcrystalline-silicon-based TFT active matrix can be reduced without increasing additional laser annealing equipment cost.

Description

A kind of tft active matrix manufacturing process based on microcrystal silicon

Technical field

The present invention relates to a kind of panel display screen and make the manufacture method in field, a kind of specifically based on the novel manufacturing method of microcrystal silicon as TFT (thin-film transistor) active matrix of active layer.

Background technology

The English full name of TFT is Thin Film Transistor, and looking like is thin-film transistor.

Tft active matrix adopts following technology manufacturing process to make: at first cleaning sputter bottom gate metal level on the clean TFT glass substrate, by photoetching process the bottom gate metallic layer graphic is handled, obtained the figure of bottom gate thin film; Then deposition insulating layer, active layer and ohmic contact layer successively on the bottom gate metal level after graphical; Next graphical treatment active layer and ohmic contact layer form the silicon island structure; Splash-proofing sputtering metal source-drain electrode layer obtains source, the drain electrode of tft active matrix after the graphical treatment again, and does to do to carve to handle raceway groove place ohmic contact layer etching is removed, and forms the TFT raceway groove; Then deposit protective layer, dried punching at quarter being made into lead-in wire and connecing the hole after the graphical treatment; Deposit one deck pixel electrode layer again, graphically be made into pixel electrode structure; Make one deck planarization layer structure at last, the tft active matrix manufacture craft finishes.

During existing tft active matrix was made, active layer manufacturing materials and method mainly contained methods such as amorphous silicon method, high temperature polysilicon method, low temperature polycrystalline silicon (LTPS) method.The amorphous silicon method adopts amorphous silicon to be used as the active layer of tft active matrix, and mobility is generally 0.5cm ²(V S) ^-1In the active layer manufacture method of polysilicon as tft active matrix, the temperature of high temperature polysilicon deposition is higher, reaches more than 600 ℃, generally can only grow on quartz glass, and it is higher to manufacture cost; The low temperature polycrystalline silicon method is a first deposition of amorphous silicon films at a lower temperature the glass substrate, and adopting the laser annealing technology again is polysilicon with the amorphous silicon crystallization, but laser annealing apparatus cost costliness has improved production cost indirectly.

A kind of tft active matrix manufacture method based on microcrystal silicon that the present invention adopts is used the active layer material of microcrystal silicon as tft active matrix, and its manufacture craft is close with the amorphous silicon manufacture craft, but mobility can reach 2 ~ 10 cm ²(V S) ^-1, than amorphous silicon material mobility big a magnitude, simultaneously the microcrystal silicon material is very stable, therefore than amorphous silicon material bigger advantage is arranged; Based on the tft active matrix of microcrystal silicon material,, can reduce manufacturing cost in a large number without the outer laser annealing apparatus cost of troughput.

Summary of the invention

The objective of the invention is provides a kind of tft active matrix manufacturing process based on microcrystal silicon at the defective that oneself has technology to exist, the tft active matrix layer adopts microcrystal silicon as active layer in this technology, on the basis that does not increase equipment cost, realize bigger mobility, reduced production cost.

For achieving the above object, the present invention adopts following technical scheme:

A kind of tft active matrix manufacturing process based on microcrystal silicon is characterized in that, selects the active layer of microcrystal silicon as the tft active matrix layer for use, and its manufacturing technology steps is as follows:

1) cleans sputter gate metal layer on the clean glass substrate, after even afterwards glue, exposure, the development, obtaining the gate electrode figure after the etching;

2) grown silicon nitride layer, microcrystal silicon active layer, ohmic contact layer, after even glue, exposure, the development, dry etching makes the silicon island structure;

3) sputtering source drain electrode layer on the silicon island that completes in the silicon island after even glue, exposure, the development, makes the source-drain electrode figure with wet etching earlier, and makes the dry etching ohmic contact layer, forms the TFT raceway groove;

4) after raceway groove completed, CVD deposition passivation protection layer--silicon nitride layer after even glue, exposure, the development, was made contact hole graph with dry etching;

5) sputtering ITO pixel electrode layer, and, etch the ITO pixel electrode by even glue, exposure, development.

So far, processing step involved in the present invention is finished.

The present invention has following conspicuous outstanding substantive distinguishing features and remarkable advantage compared with prior art:

1 compares as the active layer of tft active matrix with using amorphous silicon, and microcrystal silicon can significantly improve mobility as active layer;

2 compare as the active layer of tft active matrix with using polysilicon, can realize declining to a great extent of equipment input cost under the situation that the TFT performance guarantees.

Description of drawings

The structural representation of Fig. 1-Fig. 8 tft active matrix manufacturing process flow.

Fig. 9 tft active matrix manufacture process flow diagram.

Figure 10 microcrystal silicon is as the mobility characteristics figure of tft active matrix.

Embodiment

Below in conjunction with accompanying drawing the preferred embodiments of the present invention are described:

Embodiment 1:

Referring to Fig. 1-Fig. 8, as follows based on the tft active matrix manufacturing process of microcrystal silicon:

Glass substrate 11 is selected the TFT glass substrate for use, at first the TFT glass substrate is cleaned, and the flow process of cleaning is: utilize ultra violet lamp TFT glass baseplate surface, get rid of the organic pollution of substrate surface; At TFT glass baseplate surface spray decontamination soup, utilize cleaning brush wiper TFT glass baseplate surface again, get rid of and be deposited on the solid particle of TFT glass substrate surface diameter greater than 5 μ m; Pollute by the medium particles that high-pressure spraying is removed about diameter 3 μ m; Get rid of small pollutant about diameter 1 μ m by ultrasound unit again; Use 18M again

Washed with de-ionized water, guarantee that glass baseplate surface disposes the residual of organic substance and inorganic matter fully, glass baseplate surface is dried up dry with air knife.Above-mentioned flow process obtains clean TFT glass substrate, for the quality of the membrane structure of subsequent deposition is given security.

After glass substrate cleans and is ready to complete, deposit stratified film structure on glass substrate 11: sputter gate metal layer 12 on glass substrate at first, aluminium, molybdenum layer are as gate metal layer 12, and metallic diaphragm thickness is respectively about 2000,700; Gate metal layer 12 is carried out graphical treatment, it is spared after the technologies such as glue, photoetching, etching, obtain the gate electrode figure of gate metal layer 12.

After gate metal layer 12 graphical treatment,,, select for use silicon nitride as insulating barrier 13 at the insulating barrier 13 of deposit successively on the gate metal layer 12 about 3000 by the method for PECVD; Regrowth one deck active layer 14 selects for use the microcrystal silicon material as active layer 14, and deposition thickness is about 2000; The deposit ohmic contact layer 15 afterwards, select for use n+Si as ohmic contact layer 15, and deposition thickness is about 500.After this trilamellar membrane structure growth completes, after the technologies such as coating photoresist, photoetching, development, etching, form the silicon island structure; At surface sputtering one layer thickness is about 2000 source-drain electrode layer, is made into Lou metal electrode layer 16a, source metal electrode layer 16b after the graphical treatment, and by dry etching, is made into raceway groove, and Ohm contact electrode is respectively 15a and 15b; Utilize PECVD deposit one deck passivation protection layer 17 afterwards again, select for use silicon nitride as passivation protection layer 17, the thickness of deposit is about 2000, and it is carried out graphical treatment, with the 17 etching contact hole of the passivation protection layer on the metal electrode layer 16b of source; The ITO electrode layer 18 of growing thereon, ITO electrode layer 18 electrodes link to each other with source metal electrode layer 16b by contact hole, and graphical treatment ITO electrode layer 18 forms ITO pixel electrode 18a, and tft active matrix completes.

Embodiment 2

Present embodiment is substantially the same manner as Example 1, and special feature is:

Microcrystal silicon is as the active layer of tft active matrix, and its manufacturing process is as follows:

The used process gas of microcrystal silicon growth is respectively SiH ₄And H ₂, its purity requirement is necessary for more than 99.9999%; The suitable gas flow proportioning of microcrystal silicon growth is SiH ₄Flow is 10

1 ccm, H ₂Flow is 800

80 ccm; The growth time substrate temperature is set at 340 ℃, and power is 400W, and cavity air pressure is 650Pa during film forming, and growth time is about 420s, and the film thickness of growth is about 2000, and the mobility of measuring is 8.95 cm ²(V S) ^-1, the on-off ratio of the tft active matrix of producing is 2.2

10 ⁸

Claims

1. tft active matrix manufacturing process based on microcrystal silicon, it is characterized in that, select the active layer of microcrystal silicon for use as the tft active matrix layer, its manufacturing technology steps is as follows: 1) cleaning sputter gate metal layer (12) on the clean glass substrate (11), even afterwards glue, exposure, development obtain gate electrode figure (12) after the etching; 2) grown silicon nitride layer (13), microcrystal silicon active layer (14), ohmic contact layer (15), after even glue, exposure, the development, dry etching makes the silicon island structure; 3) sputtering source drain electrode layer on the silicon island that completes in the silicon island, after even glue, exposure, the development, earlier make the source-drain electrode figure with wet etching, make Lou metal electrode layer (16a), source metal electrode layer (16b), and make the dry etching ohmic contact layer, form TFT raceway groove, Ohm contact electrode (15a, 15b); 4) after raceway groove completed, CVD deposition passivation protection layer--silicon nitride layer (17) after even glue, exposure, the development, was made contact hole graph with dry etching; 5) sputtering ITO pixel electrode layer (18), and, etch ITO pixel electrode (18a) by even glue, exposure, development.

2. according to claims 1 described a kind of tft active matrix manufacturing process based on microcrystal silicon, it is characterized in that described microcrystal silicon is as follows as the manufacturing process of the active layer of tft active matrix: process gas is respectively SiH ₄And H ₂, its purity requirement is necessary for more than 99.9999%; The suitable gas flow proportioning of microcrystal silicon growth is SiH ₄Flow is 10

1 ccm, H ₂Flow is 800

80 ccm; The growth time substrate temperature is set at 340 ℃, and power is 400 W, and cavity air pressure is 650 Pa during film forming.