CN118007074A - IGTO sputtering target material and preparation method and application thereof - Google Patents

Abstract

The invention discloses an IGTO sputtering target material, a preparation method and application thereof, wherein the IGTO target material comprises the following components in percentage by mass: the content of In ₂O₃ is 40% -80%, the content of SnO ₂ is 10% -30%, the content of Ga ₂O₃ is 10% -30%, the content of GaN is 0.01% -2%, the content of TiO ₂ is 0.1% -3%, and the sum of the components is 100%. The IGTO sputtering target material adopts Ti and N elements for doping, has good inhibition effect on oxygen vacancies and effectively reduces carrier concentration for the sputtered film. In particular, the effect on mobility is not obvious when the specific content of Ti and N elements are mixed. The Ti is used for replacing Ga, so that the cost of the raw material of the target can be reduced, and the sputtering target can be applied to thin film transistors in the display field.

Description

An IGTO sputtering target material and its preparation method and application

Technical Field

The invention relates to the technical field of sputtering target materials, and in particular to an IGTO sputtering target material and a preparation method and application thereof.

Background technique

In TFT devices with oxide thin films as active layers, device stability and high mobility of the thin films are a pair of mutually restrictive factors. The IGZO material currently used has advantages over amorphous silicon, such as higher carrier mobility (≈10cm ² /Vs), lower preparation temperature (<400°C, far below the melting point of glass), transparency to visible light, and better electrical stability during continuous operation. However, the development of the next generation of TFT active layers for display applications requires higher mobility.

When coating on silicon substrates and Si-containing film layers, zinc elements tend to diffuse into the Si-containing layer, resulting in poor device characteristics. Since IGZO films containing Zn elements are easily etched during wet etching of the source and drain, and the etching time is long during dry etching of the active layer, replacing Zn with Sn can simultaneously improve the above etching problems. Since Sn ⁴⁺ and In ³⁺ have the same electronic configuration, they can greatly promote the effective formation of permeation pathways, thereby enhancing the mobility of the film.

As a candidate material for the next-generation active layer, IGTO (In-Ga-Sn oxide) has higher mobility than the existing IGZO. However, the poor stability of TFT devices using IGTO as the active layer has been a problem that has plagued scholars for many years, mainly including the high oxygen vacancy concentration and high carrier concentration in the film.

Therefore, it is necessary to develop a new IGTO sputtering target.

Summary of the invention

The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the first aspect of the present invention provides an IGTO sputtering target material that can effectively reduce the oxygen vacancy concentration in the film while maintaining a high carrier mobility and a low carrier concentration.

The second aspect of the present invention also provides a method for preparing an IGTO sputtering target.

The third aspect of the present invention also provides an application of an IGTO sputtering target.

According to the first aspect of the present invention, an IGTO sputtering target is provided, comprising the following components in percentage by mass:

The content of _In2O3 is ₄₀ % to ₈₀ %, the content of _SnO2 is 10% to 30%, the content of _Ga2O3 is 10% to 30%, the content of GaN is 0.01% to 2%, the content of _TiO2 is 0.1% to 3%, and the sum of the components is 100%.

The IGTO sputtering target according to the embodiment of the present invention has at least the following beneficial effects:

The IGTO sputtering target of the present invention is doped with Ti and N elements, and through synergistic effect, has a good inhibitory effect on oxygen vacancies and effectively reduces the carrier concentration for the sputtered film. And under the coordination of specific content of Ti and N elements, the influence on mobility is not obvious. Using Ti to replace Ga can reduce the cost of target raw materials, and the sputtering target of the present invention can be applied to thin film transistors in the display field.

According to some embodiments of the present invention, the following components are included in mass percentage:

The content of _In2O3 is ₄₀ % to ₈₀ %, the content of _SnO2 is 10% to 30%, the content of _Ga2O3 is 10% to 30%, the content of GaN is 0.1% to 1%, the content of _TiO2 is 0.5% to 2%, and the sum of the components is 100%. Therefore, under the formula content of the present invention, the inhibition effect is better.

According to some embodiments of the present invention, the specific surface area of In ₂ O ₃ is 6 m ² /g to 20 m ² /g.

According to some embodiments of the present invention, the specific surface area of SnO ₂ is 10 m ² /g to 25 m ² /g.

According to a second aspect of the present invention, a method for preparing an IGTO sputtering target material is provided, comprising the following steps:

S1. In ₂ O ₃ , SnO ₂ , Ga ₂ O ₃ , GaN, TiO ₂ , a binder and a plasticizer are mixed to obtain a mixed powder, which is ball-milled and spray-dried to obtain an IGTO powder;

S2, pressing the IGTO powder to obtain an embryo;

S3. Degreasing, sintering and cooling the embryo body to obtain an IGTO sputtering target.

According to some embodiments of the present invention, the added content of the binder is 0.1 wt.% to 5 wt.% of the mixed powder.

According to some embodiments of the present invention, the added content of the plasticizer is 0.03wt.% to 4wt.% of the mixed powder.

According to some embodiments of the present invention, the binder includes polyvinyl alcohol and/or polyacrylic acid.

According to some embodiments of the present invention, the plasticizer includes at least one of polyethylene glycol, polypropylene glycol or waterborne polyurethane.

According to some embodiments of the present invention, in step S1, the specific surface area of the IGTO powder is 5 m ² /g to 25 m ² /g.

According to some embodiments of the present invention, in step S1, the bulk density of the IGTO powder is 1.2 g/cm ³ to 1.6 g/cm ³ .

According to some embodiments of the present invention, in step S2, the pressure of the pressing molding is 100 MPa to 200 MPa.

According to some embodiments of the present invention, the degreasing step includes: heating the temperature to 500°C to 700°C, keeping the temperature for 2h to 3h; then heating to 900°C to 1100°C, keeping the temperature for 2h to 4h. Thus, the purpose of degreasing is to volatilize the binder and plasticizer added during the molding process. Furthermore, if the temperature is too low, the volatilization is not complete; if the temperature is too high, the volatilization rate is too fast, which will cause a large number of pores in the target.

According to some embodiments of the present invention, the sintering temperature is 1400°C to 1600°C. Thus, sintering is to make the formed body more dense and stronger, and the target formed body has conductivity after sintering. Furthermore, if the temperature is too low, the sintering process cannot occur; if the temperature is too high, over-sintering will occur, and the target will be severely deformed.

According to some embodiments of the present invention, the sintering time is 4 hours to 7 hours.

A third aspect of the present invention provides an application of an IGTO sputtering target in the preparation of a semiconductor.

Other features and advantages of the present invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present invention.

Detailed ways

The following are specific embodiments of the present invention, and the technical solutions of the present invention are further described in conjunction with the embodiments, but the present invention is not limited to these embodiments.

Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

Preparation of indium oxide (In ₂ O ₃ ) powder: Indium ingot (4N5) is dissolved and dried at room temperature using a chemical precipitation method to obtain indium hydroxide. Indium hydroxide is calcined at high temperature to form indium oxide powder, and the specific surface area of the powder is measured to be between 6m ² /g and 20m ² /g.

Preparation of tin oxide (SnO ₂ ) powder: Tin dioxide powder was prepared by chemical precipitation method, and the specific surface area of the powder was measured to be between 10 m ² /g and 25 m ² /g.

_Ga2O3 powder, _GaN powder, _TiO2 powder: purity is 99.99%, commercially available.

Example 1

This embodiment provides an IGTO target material and a preparation method thereof. The raw materials for preparing the IGTO target material are composed of the following components in mass fractions:

_In2O3 powder 60 _parts , _SnO2 powder 20 parts, _Ga2O3 powder 17.5 parts, _GaN powder 1 part, _TiO2 powder 1.5 parts

1) Mixing and granulation:

In ₂ O ₃ , SnO ₂ , Ga ₂ O ₃ , GaN, TiO ₂ , a binder and a plasticizer are mixed to obtain a mixed powder, ball-milled, and spray-dried to obtain an IGTO powder;

The added content of the binder is 2wt% of the mixed powder, and the added content of the plasticizer is 1wt% of the mixed powder. The binder is polyvinyl alcohol, and the plasticizer is polyethylene glycol.

The specific surface area of the obtained IGTO powder was 20 m ² /g, and the bulk density of the obtained IGTO powder was 1.2 g/cm ³ .

2) Compression molding:

The above powders were loaded into a mold of 1m×0.5m×0.2m, sealed, and subjected to cold isostatic pressing with a holding time of 30 minutes and a molding pressure of 150 MPa.

3) Degreasing and sintering:

Place the embryo flat in the sintering furnace, introduce inert gas, and set the heating rates of the degreasing stage and sintering stage to 2℃/min and 1℃/min respectively. Heat to 500℃ and keep for 2h, then heat to 900℃ and keep for 2h to complete the degreasing process; continue to heat to 1400℃ and keep for 4h to complete the sintering process. Finally, cool to room temperature with the furnace to obtain the IGTO target.

Example 2

This embodiment provides an IGTO target material and a preparation method thereof. The raw materials for preparing the IGTO target material are composed of the following components in mass fractions:

_In2O3 powder _60.5 parts, _SnO2 powder 20 parts, _{Ga2O3 powder} 17.5 parts, GaN powder 0.5 parts, _TiO2 powder 1.5 parts

1) Mixing and granulation:

In ₂ O ₃ , SnO ₂ , Ga ₂ O ₃ , GaN, TiO ₂ , a binder and a plasticizer are mixed to obtain a mixed powder, ball-milled, and spray-dried to obtain an IGTO powder;

The added content of the binder is 2wt% of the mixed powder; the added content of the plasticizer is 1wt% of the mixed powder; the binder is polyvinyl alcohol; the plasticizer is polypropylene glycol;

The specific surface area of the obtained IGTO powder is 20 m ² /g; and the bulk density of the obtained IGTO powder is 1.2 g/cm ³ .

2) Compression molding:

The above powders were loaded into a mold of 1m×0.5m×0.2m, sealed, and subjected to cold isostatic pressing with a holding time of 30 minutes and a molding pressure of 150 MPa.

3) Degreasing and sintering:

Place the embryo flat in the sintering furnace, introduce inert gas, set the heating rates of the degreasing stage and sintering stage to 2℃/min and 1℃/min respectively. Heat to 500℃ and keep for 2h, then heat to 900℃ and keep for 3h to complete the degreasing process; continue to heat to 1400℃ and keep for 5h to complete the sintering process. Finally, cool to room temperature with the furnace to obtain the IGTO target.

Example 3

This embodiment provides an IGTO target material and a preparation method thereof. The raw materials for preparing the IGTO target material are composed of the following components in mass fractions:

_In2O3 powder _60.7 parts, _SnO2 powder 20 parts, _{Ga2O3 powder} 17.5 parts, GaN powder 0.3 parts, _TiO2 powder 1.5 parts

1) Mixing and granulation:

In ₂ O ₃ , SnO ₂ , Ga ₂ O ₃ , GaN, TiO ₂ , a binder and a plasticizer are mixed to obtain a mixed powder, ball-milled, and spray-dried to obtain an IGTO powder;

The added content of the binder is 2wt% of the mixed powder; the added content of the plasticizer is 1wt% of the mixed powder; the binder is polyvinyl alcohol; the plasticizer is water-based polyurethane;

The specific surface area of the obtained IGTO powder is 20 m ² /g; and the bulk density of the obtained IGTO powder is 1.2 g/cm ³ .

2) Compression molding:

The above powders were loaded into a mold of 1m×0.5m×0.2m, sealed, and subjected to cold isostatic pressing with a holding time of 30 minutes and a molding pressure of 150 MPa.

3) Degreasing and sintering:

Place the embryo flat in the sintering furnace, introduce inert gas, and set the heating rates of the degreasing stage and sintering stage to 2℃/min and 1℃/min respectively. Heat to 500℃ and keep for 2h, then heat to 900℃ and keep for 3.5h to complete the degreasing process; continue to heat to 1400℃ and keep for 6h to complete the sintering process. Finally, cool to room temperature with the furnace to obtain the IGTO target.

Example 4

This embodiment provides an IGTO target material and a preparation method thereof. The raw materials for preparing the IGTO target material are composed of the following components in mass fractions:

_In2O3 powder _60.95 parts, _SnO2 powder 20 parts, _{Ga2O3 powder} 17.5 parts, GaN powder 0.05 parts, _TiO2 powder 1.5 parts

1) Mixing and granulation:

In ₂ O ₃ , SnO ₂ , Ga ₂ O ₃ , GaN, TiO ₂ , a binder and a plasticizer are mixed to obtain a mixed powder, ball-milled, and spray-dried to obtain an IGTO powder;

The added content of the binder is 2wt% of the mixed powder; the added content of the plasticizer is 1wt% of the mixed powder; the binder is polyvinyl alcohol and polyacrylic acid; the plasticizer is polyethylene glycol;

The specific surface area of the obtained IGTO powder is 20 m ² /g; and the bulk density of the obtained IGTO powder is 1.2 g/cm ³ .

2) Compression molding:

The above powders were loaded into a mold of 1m×0.5m×0.2m, sealed, and subjected to cold isostatic pressing with a holding time of 30 minutes and a molding pressure of 150 MPa.

3) Degreasing and sintering:

Place the embryo flat in the sintering furnace, introduce inert gas, and set the heating rates of the degreasing stage and sintering stage to 2℃/min and 1℃/min respectively. Heat to 500℃ and keep for 2h, then heat to 900℃ and keep for 4h to complete the degreasing process; continue to heat to 1400℃ and keep for 7h to complete the sintering process. Finally, cool to room temperature with the furnace to obtain the IGTO target.

Example 5

This embodiment provides an IGTO target material and a preparation method thereof. The difference between this embodiment and Example 1 is only the difference in the mass fractions of some of the preparation raw material components: 61.4 parts _{of In2O3} powder, 20 parts of _SnO2 powder, 17.5 parts _{of Ga2O3} powder, 1 part of GaN powder, and 0.1 part of _TiO2 powder. The remaining raw material components and preparation method are consistent with Example 1.

Example 6

This embodiment provides an IGTO target material and a preparation method thereof. The difference between this embodiment and Example 1 is only the difference in the mass fractions of some of the preparation raw material components: 61 parts _{of In2O3} powder, 20 parts of _SnO2 powder, 17.5 parts _{of Ga2O3 powder} , 1 part of GaN powder, and 0.5 parts of _TiO2 powder. The remaining raw material components and preparation method are consistent with Example 1.

Example 7

This embodiment provides an IGTO target material and a preparation method thereof. The difference between this embodiment and Example 1 is only the difference in the mass fractions of some of the preparation raw material components: 60.5 parts _{of In2O3} powder, 20 parts of _SnO2 powder, 17.5 parts of _Ga2O3 powder, 1 part of _GaN powder, and 1 part of _TiO2 powder. The remaining raw material components and preparation method are consistent with Example 1.

Example 8

This embodiment provides an IGTO target material and a preparation method thereof. The difference between this embodiment and Example 1 is only the difference in the mass fractions of some of the preparation raw material components: 59.5 parts _{of In2O3} powder, 20 parts of _SnO2 powder, 17.5 parts of _Ga2O3 powder, 1 part of _GaN powder, and 2 parts of _TiO2 powder. The remaining raw material components and preparation method are consistent with Example 1.

Comparative Example 1

This comparative example provides an IGTO target material and a preparation method thereof. The difference between this comparative example and Example 1 is only the difference in the mass fractions of some of the preparation raw material components: 60 parts _{of In2O3} powder, 20 parts of _SnO2 powder, and 20 parts of _{Ga2O3 powder} . The remaining raw material components and preparation method are consistent with Example 1.

Comparative Example 2

This comparative example provides an IGTO target material and a preparation method thereof. The difference between this comparative example and Example 1 lies only in the difference in the mass fractions of some of the preparation raw material components: 60 parts _{of In2O3} powder, 20 parts of _SnO2 powder, 18.5 parts _{of Ga2O3} powder, and 1.5 parts of _TiO2 powder. The remaining raw material components and preparation method are consistent with Example 1.

Comparative Example 3

This comparative example provides an IGTO target material and a preparation method thereof. The difference between this comparative example and Example 1 lies only in the difference in the mass fractions of some of the preparation raw material components: 60 parts _{of In2O3} powder, 20 parts of _SnO2 powder, 19 parts of _{Ga2O3 powder} , and 1 part of GaN powder. The remaining raw material components and preparation method are consistent with Example 1.

Comparative Example 4

This comparative example provides an IGTO target material and a preparation method thereof. The difference between this comparative example and Example 1 lies only in the difference in the mass fractions of some of the preparation raw material components: 60 parts _{of In2O3} powder, 20 parts of _SnO2 powder, 17.5 parts _{of Ga2O3} powder, and 1 part of TiN powder. The remaining raw material components and preparation method are consistent with Example 1.

Comparative Example 5

This comparative example provides an IGTO target material and a preparation method thereof. The difference between this comparative example and Example 1 lies only in the difference in the mass fractions of some of the preparation raw material components: 60 parts _{of In2O3} powder, 20 parts of _SnO2 powder, 17.5 parts _{of Ga2O3} powder, and 1.5 parts of TiN powder. The remaining raw material components and preparation method are consistent with Example 1.

Coating test

On the cleaned glass substrate, IGTO thin film was deposited by sputtering, with a coating power density of 1-5kW/ ^cm2 and a deposition thickness of 40nm, and the carrier concentration and mobility of the thin film were tested. The area ratio of the oxygen vacancy peak (531.6eV) in the O1s peak was determined by X-ray photoelectron spectroscopy (XPS). The data are shown in Table 1.

Table 1 Examples 1 to 8 and Comparative Examples 1 to 5

From Table 1, it can be seen that the IGTO sputtering target of the present invention is doped with Ti and N elements. Due to the synergistic effect of _TiO2 and GaN, the number of oxygen vacancies and carrier concentration in the IGTO sputtering film can be effectively reduced, and the effect on the mobility is not obvious.

The above is a detailed description of the embodiments of the present invention, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims (10)

1. An IGTO sputtering target, characterized in that it comprises the following components in mass percentage: The content of _In2O3 is ₄₀ % to ₈₀ %, the content of _SnO2 is 10% to 30%, the content of _Ga2O3 is 10% to 30%, the content of GaN is 0.01% to 2%, the content of _TiO2 is 0.1% to 3%, and the sum of the components is 100%. 2. The IGTO sputtering target according to claim 1, characterized in that it comprises the following components in mass percentage: The content of _In2O3 is ₄₀ % to ₈₀ %, the content of _SnO2 is 10% to 30%, the content of _Ga2O3 is 10% to 30%, the content of GaN is 0.1% to 1%, the content of _TiO2 is 0.5% to 2%, and the sum of the components is 100%. 3 . The IGTO sputtering target according to claim 1 , wherein the specific surface area of the In ₂ O ₃ is 6 m ² /g to 20 m ² /g. 4 . The IGTO sputtering target according to claim 1 , wherein the specific surface area of SnO ₂ is 10 m ² /g to 25 m ² /g. 5. The method for preparing an IGTO sputtering target according to any one of claims 1 to 4, characterized in that it comprises the following steps: S1. In ₂ O ₃ , SnO ₂ , Ga ₂ O ₃ , GaN, TiO ₂ , a binder and a plasticizer are mixed to obtain a mixed powder, which is ball-milled and dried to obtain an IGTO powder; S2, pressing the IGTO powder to obtain an embryo; S3, degreasing, sintering and cooling the embryo body to obtain the IGTO sputtering target. 6 . The method for preparing an IGTO sputtering target according to claim 5 , wherein in step S2 , the pressure of the pressing molding is 100 MPa to 200 MPa. 7. The method for preparing an IGTO sputtering target according to claim 5, characterized in that the degreasing step comprises: heating the temperature to 500°C to 700°C and keeping it warm for 2h to 3h; then heating the temperature to 900°C to 1100°C and keeping it warm for 2h to 4h. 8 . The method for preparing an IGTO sputtering target according to claim 5 , wherein the sintering temperature is 1400° C. to 1600° C. 9 . The method for preparing an IGTO sputtering target according to claim 5 , wherein the sintering time is 4 h to 7 h. 10. Use of the IGTO sputtering target according to any one of claims 1 to 4 in the preparation of semiconductors.