CN106098617A - A kind of wide viewing angle pattern TFT substrate preparation method - Google Patents

Abstract

The invention discloses a method for preparing a TFT substrate with a wide viewing angle mode. The method comprises: a process of depositing a Gate layer on a substrate; a process of depositing an island layer by using a CVD process; a process of depositing a first ITO layer; a process of depositing a source and drain layer; and a process of depositing a PA layer by using a PECVD process. ; In this process, including: dissociate the process gas of this process into plasma with a relatively low power, perform reactive deposition as the first PA layer, and process gas with another relatively high power Dissociate into plasma, carry out reactive deposition as the second PA layer; deposit the second ITO layer process. Applying the technical solution of the present invention can avoid reducing the first ITO layer during the preparation process, thereby protecting the electrical and optical properties of the first ITO layer, and at the same time improving the transmittance of the TFT substrate, thereby reducing the power consumption of the TFT display .

Description

A kind of wide viewing angle mode TFT substrate preparation method

technical field

The invention relates to the fields of semiconductor device preparation and display, in particular to a method for preparing a TFT substrate with a wide viewing angle mode.

Background technique

TFT LCD (Thin-Film-Transistor Liquid Crystal Display, Thin-Film-Transistor Liquid Crystal Display) has been widely used due to its high speed, high brightness, high contrast and other advantages. There are many modes of TFT substrates, the more common ones are TN, IPS, MVA and so on. TN mode has the fastest response speed, but the worst color, relatively small viewing angle, and low cost. It is mainly used in monitors and small TVs. The TFT substrate in wide viewing angle mode has a viewing angle of more than 170°. Typical of IPS mode, the viewing angle is relatively high, the response speed is fast, the color is accurate, and the cost is moderate.

In the traditional technology, the TFT substrate of the wide viewing angle mode needs to go through multiple processes in the preparation process to make different material film layers, including the Gate layer, the island layer, the D/S (source-drain) layer, the first ITO layer, PA (protective layer), second ITO layer. Some non-metallic material film layers are produced by CVD (Chemical Vapor Deposition, chemical vapor deposition) process, for example, PA is deposited by PECVD method.

The inventor found in research that the conventional technology has at least the following problems: in the process of using PECVD to make the PA layer, the process gas forming the PA layer will form a plasma, which contains a large amount of H ions and electrons, H ions and these The electrons may undergo a reduction reaction with the exposed first ITO layer of the substrate, thereby affecting the electrical and optical properties of the first ITO layer of the final wide viewing angle TFT substrate and reducing the yield of the finished product.

Contents of the invention

Based on this, it is necessary to provide a method for preparing a TFT substrate with a wide viewing angle mode, which can reduce the probability of reduction reaction between H ions and electrons and the exposed first ITO layer in the process of preparing PA by PECVD, thereby improving the overall performance of the finished TFT substrate. on the yield rate.

A method for preparing a TFT substrate with a wide viewing angle mode, comprising:

The process of depositing the Gate layer on the substrate;

The process of depositing the island layer by CVD process;

The process of depositing the first ITO layer;

The process of depositing the source and drain layers;

The process of depositing the PA layer by using PECVD process; in this process, it includes: dissociate the process gas of this process into plasma with a relatively low power, perform reaction deposition to form the first PA layer, and use another relatively low power The higher power dissociates the process gas into plasma, which is reactively deposited as the second PA layer;

The process of depositing the second ITO layer.

In one embodiment, the process of depositing a PA layer using PECVD process includes:

The substrate that has passed through the previous steps of this process enters the PECVD process chamber;

cleaning by plasma cleaning gas;

Dissociate the process gas in this process into plasma with a relatively low power through the process gas in this process, and perform reaction deposition to form the first PA layer;

Dissociate the process gas into plasma with another relatively high power, and perform reactive deposition to form a second PA layer;

Optimize the static removal of the substrate after the previous steps;

The substrate is removed from the PECVD process chamber.

In one embodiment, in the step of dissociating the process gas in this process into plasma with a relatively low power, and performing reactive deposition as the first PA layer:

The radio frequency power supply for generating plasma is 800-1500W; the process gases include N2, NH3, SiH4, the gas flow rates are 6000sccm, 2000sccm, 220sccm respectively, and the pressure inside the PECVD chamber is 1200mTorr.

In one embodiment, the deposited first PA layer has a thickness of 200˜300 Å.

In one embodiment, in the step of dissociating the process gas into plasma with another relatively high power, and performing reactive deposition as the second PA layer:

The radio frequency power supply for generating plasma is 2500-3500W; the process gases include N2, NH3, SiH4, the gas flow rates are 7850sccm, 3360sccm, 750sccm respectively, and the pressure inside the PECVD chamber is 1500mTorr.

In one embodiment, the plasma cleaning gas is N2, NH3 or its mixed gas plasma; during the cleaning process, the pressure value in the PECVD chamber is 1500mTorr, the gas flow is 1500sccm, and the plasma is generated The power of the RF power supply is 300-500W.

In one embodiment, the step of optimizing the static removal of the substrate after the aforementioned steps includes:

Through H2, the gas flow is 800 sccm, the pressure of the PECVD chamber is 1500 mTorr, and a radio frequency power source is used to generate plasma to remove static electricity.

In one embodiment, the process of depositing the Gate layer on the substrate, the process of depositing the first ITO layer, the process of depositing the source drain layer, and the process of depositing the second ITO layer, adopt PVD film forming process.

In the preparation method of the TFT substrate with a wide viewing angle mode, in the process of depositing the PA layer using the PECVD process, the process gas in this process is first dissociated into plasma with a relatively low power, and the first PA layer is deposited by reaction. The H ions and electrons in the plasma gas have lower energy, thereby inhibiting the reduction reaction between the H ions and electrons and the exposed first ITO layer, thereby ensuring the electric field and optics between the first ITO layer and the second ITO layer. performance, improving the yield of TFT substrates.

Description of drawings

FIG. 1 is a schematic flow diagram of a method for preparing a TFT substrate with a wide viewing angle mode in one embodiment;

FIG. 2 is a schematic structural view of a wide viewing angle mode TFT substrate in an embodiment;

FIG. 3 is a schematic flow chart of the process of depositing a PA layer in one embodiment.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

Referring to Figures 1 and 2, in one embodiment a method for preparing a TFT substrate with a wide viewing angle mode is provided, including:

101. A process of depositing a Gate layer on a substrate.

Specifically, a PVD (Physical Vapor Deposition, physical vapor deposition) film-forming process may be used to deposit metal on the substrate 20 , and obtain the Gate pattern 21 through process treatment.

102. A process of depositing an island layer by using a CVD process.

Specifically, the island (Island) layer is a non-metal film layer, including G-SiNx (221 in FIG. 2 ), a-Si (region 222 in FIG. 2 ), and n ⁺ a-Si (223 in FIG. 2 ).

103. A process of depositing a first ITO layer.

Specifically, PVD is used to deposit ITO, and the first ITO is shown as 23 in FIG. 2 .

104 , a process of depositing a source and drain layer.

Specifically, on the basis of the foregoing, a metal layer is deposited, and a source-drain (S/D) pattern 24 is obtained through processing.

105. A process of depositing a PA layer by using a PECVD process.

Specifically, the PA layer is 25 in FIG. 2 , which is a non-metallic layer. The process is PECVD process. Since the first ITO layer is bare (the source and drain layers do not cover the first ITO layer), in order to avoid the reduction reaction between H ions and electrons in the plasma and the first ITO layer (containing In ₂ O ₃ , SnO ₂ ) , in this process, the process gas in this process is first dissociated into plasma with a relatively low power, and the first PA layer is reacted and deposited, and then the process gas is dissociated into plasma with another relatively high power. Plasma, for reactive deposition as the second PA layer.

106. A process of depositing a second ITO layer.

Specifically, the second ITO layer is 26 in FIG. 2 , and a PVD film forming process is adopted.

In the preparation method of the TFT substrate with a wide viewing angle mode, in the process of depositing the PA layer using the PECVD process, the process gas in this process is first dissociated into plasma with a relatively low power, and the first PA layer is deposited by reaction. The H ions and electrons in the plasma gas have lower energy, thereby inhibiting the reduction reaction between the H ions and electrons and the exposed first ITO layer, thereby ensuring the electric field and optics between the first ITO layer and the second ITO layer. performance, improving the yield of TFT substrates.

In Fig. 3 embodiment, adopt PECVD process, the operation of depositing PA layer comprises:

301. The substrate that has gone through the preceding steps of this step enters the PECVD process chamber.

302. Perform cleaning by using plasma cleaning gas.

The main function of the plasma cleaning gas is to inhibit the inside of the film and cannot react with the first ITO layer. It can be preferred from the subsequent process gases. For example, the plasma cleaning gas is N2, NH3 or its mixed gas plasma. During the cleaning process, the pressure in the PECVD chamber is 1500 mTorr, the gas flow is 1500 sccm, and the radio frequency power supply for generating plasma is 300-500 W.

303 , perform PECVD film formation by using the process gas in this step.

Specifically, through the process gas in this process, the process gas in this process is dissociated into plasma with a relatively low power, and the first PA layer is reacted and deposited, wherein the radio frequency power supply for generating plasma is 800-1500W ; The process gas includes N2, NH3, SiH4, the gas flow rate is 6000sccm, 2000sccm, 220sccm respectively, and the pressure in the PECVD chamber is 1200mTorr. The thickness of the deposited first PA layer is 200-300A. Then dissociate the process gas into plasma with another relatively high power, and carry out reaction deposition to form the second PA layer. The radio frequency power supply for generating plasma is 2500-3500W; the process gas includes N2, NH3, For SiH4, the gas flow rates are 7850 sccm, 3360 sccm, and 750 sccm respectively, and the pressure in the PECVD chamber is 1500 mTorr.

304. Perform optimized static removal on the substrate that has gone through the preceding steps.

Specifically, through H2, the gas flow rate is 800 sccm, the pressure of the PECVD chamber is 1500 mTorr, and the plasma is generated by using a radio frequency power source to remove static electricity.

305. Remove the substrate from the PECVD process chamber.

The above-mentioned embodiments only express several implementation modes of the present invention, and the description thereof is relatively specific and detailed, but should not be construed as limiting the patent scope of the present invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (8)

1. a wide viewing angle pattern TFT substrate preparation method, it is characterised in that described method includes:

Substrate deposits the operation of Gate layer；

Use CVD technique, the operation of deposition island layer；

Deposit the operation of the first ITO layer；

The operation of deposition source drain layer；

Use pecvd process, the operation of deposition PA layer；In this operation, including: with a relatively low power by this operation Process gas is dissociated into plasma, and carrying out reactive deposition is a PA layer, and with another of a relatively high power by described Process gas is dissociated into plasma, and carrying out reactive deposition is the 2nd PA layer；

Deposit the operation of the second ITO layer.

Method the most according to claim 1, it is characterised in that described employing pecvd process, the operation bag of deposition PA layer Include:

Substrate through this operation foregoing sequence enters pecvd process chamber；

It is cleaned by plasma cleaning gas；

By the process gas of this operation, with a relatively low power, the process gas of this operation is dissociated into plasma, Carrying out reactive deposition is a PA layer；

With another of a relatively high power, described process gas being dissociated into plasma, carrying out reactive deposition is the 2nd PA layer；

Substrate through abovementioned steps is optimized and destatics；

Substrate is removed from described pecvd process chamber.

Method the most according to claim 2, it is characterised in that described with a relatively low power by the work of this operation Process gases is dissociated into plasma, carries out in the step that reactive deposition is a PA layer:

The radio-frequency power supply power producing plasma is 800～1500W；Described process gas includes N2, NH3, SiH4, gas stream Amount is respectively 6000sccm, 2000sccm, 220sccm, and described PECVD cavity indoor pressure is 1200mTorr.

Method the most according to claim 3, it is characterised in that the thickness of a PA layer of deposition is 200～300A.

Method the most according to claim 2, it is characterised in that described with another of a relatively high power by described technique Gas is dissociated into plasma, carries out in the step that reactive deposition is the 2nd PA layer:

The radio-frequency power supply power producing plasma is 2500～3500W；Described process gas includes N2, NH3, SiH4, gas Flow is respectively 7850sccm, 3360sccm, 750sccm, and described PECVD cavity indoor pressure is 1500mTorr.

Method the most according to claim 2, it is characterised in that described plasma cleaning gas is N2, NH3 or its mixing Gaseous plasma；During being cleaned, the force value in described PECVD chamber is 1500mTorr, and throughput is 1500sccm, the radio-frequency power supply power producing plasma is 300～500W.

Method the most according to claim 2, it is characterised in that described the substrate through abovementioned steps is optimized except quiet The step of electricity, including:

By H2, throughput is 800sccm, and described PECVD chamber pressure is 1500mTorr, utilize radio-frequency power supply generation etc. from Daughter destatics.

Method the most according to claim 1, it is characterised in that the described operation depositing Gate layer on substrate, described heavy The operation of long-pending first ITO layer, the operation of described deposition source drain layer, and the operation of described deposition the second ITO layer, use PVD film-forming process.