CN101958250A

CN101958250A - Process for manufacturing low-temperature polycrystalline silicon TFT (Thin Film Transistor)

Info

Publication number: CN101958250A
Application number: CN2010102111532A
Authority: CN
Inventors: 徐正勋
Original assignee: Sichuan CCO Display Technology Co Ltd
Current assignee: Sichuan CCO Display Technology Co Ltd
Priority date: 2010-06-28
Filing date: 2010-06-28
Publication date: 2011-01-26
Anticipated expiration: 2030-06-28
Also published as: CN101958250B

Abstract

The invention provides a manufacturing process for converting an amorphous silicon TFT (Thin Film Transistor) into a polycrystalline silicon TFT. The characteristics of the polycrystalline silicon TFT manufactured by the process cannot be reduced. In the manufacturing process of the low-temperature polycrystalline silicon TFT, after an ITO (Indium Tin Oxide) film forming process is finished, hydrogen is injected into silicon through a hydrogen injection process to recover the reduced characteristics of the TFT in the process. In the invention, the hydrogen is renewedly injected, thus the process has the effect of recovering the reinforced combination characteristics of the silicon.

Description

The manufacture craft of low temperature polycrystalline silicon TFT

Technical field

The present invention relates to a kind of manufacture craft that adopts non-crystalline silicon tft to transform to multi-crystal TFT.

Background technology

When making AMOLED, need TFT (thin-film transistor) to control the ON/OFF and the brightness of pixel at each pixel place, the difference of channel part material when making according to TFT can be divided into non-crystalline silicon tft, multi-crystal TFT, organic tft etc.Multi-crystal TFT is compared non-crystalline silicon tft, has advantage at aspects such as quality, stability, fast tens of times to hundreds of times approximately of multi-crystal TFT electron mobilities than non-crystalline silicon tft, and has the advantage on the drive IC that can be integrated in outside display, when can making the compact device, also can make high-resolution, high-grade device.

At present, the manufacture craft of multi-crystal TFT mainly contains two kinds, and a kind of is that direct synthetically grown obtains.But there are shortcomings such as initial investment height, crystallization process difficulty, maximization technology be incomplete; Another kind is to adopt non-crystalline silicon tft to transform to obtain.Because the manufacture craft technology of non-crystalline silicon tft and maximization technology are quite ripe, but non-crystalline silicon tft needs hot conditions in multi-crystal TFT transforms, can't use cheap glass substrate, must use expensive quartz base plate.Yet along with the development of low temperature polycrystalline silicon TFT, the application of non-crystalline silicon tft on AMOLED begins the possibility that becomes.But in polysilicon manufacturing process, the dehydrogenation phenomenon of silicon can take place, cause the characteristic of multi-crystal TFT to reduce.

Summary of the invention

Technical problem to be solved by this invention provides a kind of manufacture craft that adopts non-crystalline silicon tft to transform to multi-crystal TFT, and the multi-crystal TFT characteristic that this technology is made can not reduce.

The technical scheme that technical solution problem of the present invention is adopted is: the manufacture craft of low temperature polycrystalline silicon TFT, after finishing the ITO film-forming process, silicon is injected hydrogen by the hydrogen injection technology, and the TFT characteristic that reduces in the technical process is replied.

The invention has the beneficial effects as follows: because hydrogen deviates from from silicon atom, cause the transistor characteristic variation, so the present invention adopts and refill hydrogen, have the reinforcement binding characteristic effect of recovering silicon.

Description of drawings

Fig. 1 is the I-V curve chart that obtains after ion injection and activate are handled having carried out.Among the figure, threshold voltage (10.1)=-5.5; The inferior threshold values amplitude of oscillation (5.1)=0.62737; Mobility (0.1)=-53.91304; Mobility (10.1)=-49.93543; ON state current (10.1)=2.85E-4; Off-state current (10.1) @min.=3.66E-11; Off-state current (10.1) @5V=5.45E-11; ON/OFF is than (10.1)=7.78689E6.

Fig. 2 is the I-V curve chart that obtains after contact hole, metal level and VIA layer are handled having carried out again on the basis of Fig. 1.Among the figure, threshold voltage (10.1)=-1.8; The inferior threshold values amplitude of oscillation (5.1)=2.31091; Mobility (0.1)=-4.31884; Mobility (10.1)=-10.61845; ON state current (10.1)=2.86E-5; Off-state current (10.1) @min.=4.2E-11; Off-state current (10.1) @5V=1.002E-10; ON/OFF is than (10.1)=680952.38095.

Fig. 3 is the I-V curve that obtains after hydrogen injection of the present invention is handled having carried out, and production process carries out in proper order according to contact hole+metal level+VIA layer.Among the figure, threshold voltage (10.1)=-6; The inferior threshold values amplitude of oscillation (5.1)=0.62785; Mobility (0.1)=-28.95652; Mobility (10.1)=-24.10678; ON state current (10.1)=1.06E-4; Off-state current (10.1) @min.=-1.679E-11; Off-state current (10.1) @5V=1.768E-11; ON/OFF than (10.1)=-6.31328E6.

Embodiment

Adopt non-crystalline silicon tft as follows at present to the low temperature polycrystalline silicon manufacture method that multi-crystal TFT transforms:

1) on glass substrate, plates amorphous silicon, and amorphous silicon is carried out rag;

2) at source electrode and drain locations evaporation metal nickel, and by crystallization formation polysilicon;

3) finish gate insulator and metal electrode layer plated film after, carry out rag;

4) after ion injects, carry out activate heat treatment;

5) insulating barrier between coating carries out contact hole etching afterwards;

6) behind the source of finishing/drain metal plated film, carry out rag;

7) finish VIA layer film forming after, carry out the contact hole etching of connection source/drain electrode and ITO layer;

8) carry out rag after having plated the ITO film;

9), only expose the thin-film package technology of ITO layer at substrate surface by polymeric photoresist.

The present invention is to inserting the hydrogen injection technology in the existing low temperature polycrystalline silicon technology, its concrete manufacture method is as follows:

4) after ion injects, carry out activate heat treatment;

6) behind the source of finishing/drain metal plated film, carry out rag;

8) carry out rag after having plated the ITO film;

9) hydrogen injects and handles;

The mode that hydrogen injects and the activate heat treatment phase of low temperature polycrystalline silicon are together, handle between 500 ℃ at 400 ℃, later each the bed boundary characteristic of activate technology is subjected to the glass effect of contraction and variation along with high-temperature process, therefore must carry out PROCESS FOR TREATMENT under alap high temperature.Hydrogen injects the hydrogen of handling same amount in the time of must injecting with activate technology.Because hydrogen deviates from from silicon atom, cause the transistor characteristic variation, so the present invention adopts and refills hydrogen, have the reinforcement binding characteristic effect of recovering silicon.

10), only expose the thin-film package technology of ITO layer at substrate surface by polymeric photoresist.

Fig. 1, Fig. 2 are when importing different drain voltage on thin-film transistor with Fig. 3, along with grid voltage changes, and the I-V curve characteristic that presents, wherein, first curve (1) is fixing input 0.1V drain voltage, changes drain current value situation of change according to grid voltage; Second curve (2) is fixing input 5.1V drain voltage, changes drain current value situation of change according to grid voltage; The 3rd curve (3) is fixing input 10.1V drain voltage, changes drain current value situation of change according to grid voltage; The 4th curve (4) is fixing input 15.1V drain voltage, changes drain current value situation of change according to grid voltage.Because generally speaking, import the drain voltage of 5V-10V on the AMOLED panel panel is lighted, therefore, the data the when data among Fig. 1, Fig. 2 and Fig. 3 are 10.1V with the drain voltage are as the criterion, and just are as the criterion with the 3rd curve (3).Numerical value in expanding among Fig. 1, Fig. 2 and Fig. 3 number is the value of drain voltage, that is to say that the data among Fig. 1, Fig. 2 and Fig. 3 are the data that obtain under respective drain voltage.

Well-known OLED characteristic has determined it to be current drives, only under high charge carrier characteristic, just has good panel characteristics, and the charge carrier characteristic postpones also to exert an influence to the subthreshold value amplitude of oscillation, leakage current or ON/OFF simultaneously.From Fig. 1, can see among Fig. 2 and Fig. 3, after activate is handled, the characteristic of thin-film transistor along with after contact hole or metal rag, the carrying out of VIA hole technology etc., subthreshold value amplitude of oscillation variation (more than＞1), the ON/OFF time delay that causes thin-film transistor, when evaporation insulating barrier or metal level, because heat-treated technogenic influence, the silicon that forms thin-film transistor source/drain electrode is in conjunction with variation, cause the carrier mobility that is closely related with current characteristics significantly to reduce, this point can obviously be observed in Fig. 2, after adding the Technology for Heating Processing of hydrogen, though silicon is recovered in conjunction with 100%, the silicon combination more than 90% is recovered, can see the characteristic recovery effects from Fig. 1 and Fig. 3.

Claims

1. the manufacture craft of low temperature polycrystalline silicon TFT is characterized in that: after finishing the ITO film-forming process, by the hydrogen injection technology silicon is injected hydrogen, the TFT characteristic that reduces in the process engineering is replied.

2. the manufacture craft of low temperature polycrystalline silicon TFT as claimed in claim 1 is characterized in that: described hydrogen injection technology is carried out between 400 ℃ to 500 ℃.

3. the manufacture craft of low temperature polycrystalline silicon TFT as claimed in claim 1 is characterized in that: the hydrogen of same amount when described hydrogen injection technology is injected with activate technology.