IGTO sputtering target material, method for preparing the same, and use thereof

Abstract

This invention discloses an IGTO sputtering target, its preparation method, and its applications. The IGTO target of this invention comprises the following components by mass percentage: In₂O₃ content of 40%–80%, SnO₂ content of 10%–30%, Ga₂O₃ content of 10%–30%, GaN content of 0.01%–2%, and TiO₂ content of 0.1%–3%, with the sum of all components being 100%. The IGTO sputtering target of this invention uses Ti and N elements for doping, which effectively suppresses oxygen vacancies and reduces carrier concentration in the sputtered film. Especially with specific combinations of Ti and N elements, the effect on mobility is not significant. Using Ti instead of Ga can reduce the cost of target raw materials, and the sputtering target of this invention can be applied to thin-film transistors in the display field.

Description

Technical Field

[0001] This invention relates to the field of sputtering target technology, and in particular to an IGTO sputtering target, its preparation method, and its application. Background Technology

[0002] In TFT devices with oxide thin films as the active layer, device stability and high carrier mobility are mutually restrictive factors. Currently, the mainstream IGZO material has a higher carrier mobility (≈10 cm⁻¹) compared to amorphous silicon. 2 It has advantages such as low processing temperature (<400℃, far below the melting point of glass), transparency to visible light, and good electrical stability during continuous operation. However, to develop the next generation of TFT active layers for displays, higher mobility is required.

[0003] When depositing zinc films on silicon substrates and Si-containing layers, zinc tends to diffuse into the Si-containing layer, leading to deterioration in device characteristics. Since Zn-containing IGZO films are easily etched during wet etching of the source and drain electrodes, and the etching time for the active layer is long during dry etching, replacing Zn with Sn can simultaneously improve these etching process issues. Because Sn... 4+ and In 3+ Having the same electronic configuration can greatly promote the effective formation of permeation pathways, thereby enhancing the mobility of the thin film.

[0004] As a candidate material for the next generation of active layers, IGTO (In-Ga-Sn oxide) has a higher mobility than the existing IGZO. However, the poor stability of TFT devices with IGTO as the active layer has been a problem that has plagued researchers for many years, mainly due to the high oxygen vacancy concentration and high carrier concentration of the thin film.

[0005] Therefore, it is necessary to develop a new IGTO sputtering target. Summary of the Invention

[0006] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the first aspect of the present invention proposes an IGTO sputtering target that can effectively reduce the oxygen vacancy concentration in the thin film while maintaining a high carrier mobility and a low carrier concentration.

[0007] A second aspect of the present invention also provides a method for preparing an IGTO sputtering target.

[0008] A third aspect of the present invention also provides an application of an IGTO sputtering target.

[0009] An IGTO sputtering target according to a first aspect embodiment of the present invention comprises the following components by mass percentage:

[0010] The content of In2O3 is 40%–80%, the content of SnO2 is 10%–30%, the content of Ga2O3 is 10%–30%, the content of GaN is 0.01%–2%, and the content of TiO2 is 0.1%–3%, with the sum of all components being 100%.

[0011] The IGTO sputtering target according to embodiments of the present invention has at least the following beneficial effects:

[0012] The IGTO sputtering target of this invention is doped with Ti and N elements. Through synergistic effects, it effectively suppresses oxygen vacancies and reduces carrier concentration in the sputtered film. Furthermore, with specific amounts of Ti and N, the effect on mobility is not significant. Using Ti instead of Ga can reduce the cost of target materials, and the sputtering target of this invention can be applied to thin-film transistors in the display field.

[0013] According to some embodiments of the present invention, the components include the following components by mass percentage:

[0014] The In2O3 content is 40%–80%, the SnO2 content is 10%–30%, the Ga2O3 content is 10%–30%, the GaN content is 0.1%–1%, and the TiO2 content is 0.5%–2%, with the sum of all components being 100%. Therefore, at the formulation content of this invention, the inhibition effect is better.

[0015] According to some embodiments of the present invention, the specific surface area of ​​the In₂O₃ is 6 m². 2 / g~20m 2 / g.

[0016] According to some embodiments of the present invention, the specific surface area of ​​the SnO2 is 10 m². 2 / g~25m 2 / g.

[0017] The method for preparing an IGTO sputtering target according to a second aspect embodiment of the present invention includes the following steps:

[0018] S1. Mix In2O3, SnO2, Ga2O3, GaN, TiO2, binder and plasticizer to obtain mixed powder, ball mill, and spray dry to obtain IGTO powder;

[0019] S2. Press the IGTO powder into a preform to obtain a preform;

[0020] S3. The preform is degreased, sintered, and cooled to obtain the IGTO sputtering target.

[0021] According to some embodiments of the present invention, the amount of the binder added is 0.1 wt.% to 5 wt.% of the mixed powder.

[0022] According to some embodiments of the present invention, the plasticizer is added at a content of 0.03 wt.% to 4 wt.% of the mixed powder.

[0023] According to some embodiments of the present invention, the adhesive comprises polyvinyl alcohol and / or polyacrylic acid.

[0024] According to some embodiments of the present invention, the plasticizer includes at least one of polyethylene glycol, polypropylene glycol, or waterborne polyurethane.

[0025] According to some embodiments of the present invention, in step S1, the specific surface area of ​​the IGTO powder is 5m². 2 / g~25m 2 / g.

[0026] According to some embodiments of the present invention, in step S1, the loose packing density of the IGTO powder is 1.2 g / cm³. 3 ~1.6g / cm 3 .

[0027] According to some embodiments of the present invention, in step S2, the pressure of the pressing molding is 100MPa to 200MPa.

[0028] According to some embodiments of the present invention, the degreasing step includes: heating to 500℃~700℃ and holding for 2h~3h; then raising the temperature to 900~1100℃ and holding for 2h~4h. Thus, the purpose of degreasing is to volatilize the binders and plasticizers added during the molding process. Furthermore, if the temperature is too low, volatilization will be incomplete; if the temperature is too high, the volatilization rate will be too fast, resulting in a large number of pores in the target.

[0029] According to some embodiments of the present invention, the sintering temperature is 1400℃~1600℃. Therefore, sintering is used to make the formed body more dense and stronger, and the target material becomes conductive 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 material will be severely deformed.

[0030] According to some embodiments of the present invention, the sintering time is 4h to 7h.

[0031] A third aspect of the present invention provides an application of an IGTO sputtering target in the fabrication of semiconductors.

[0032] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Detailed Implementation

[0033] The following are specific embodiments of the present invention, and the technical solutions of the present invention will be further described in conjunction with the embodiments, but the present invention is not limited to these embodiments.

[0034] Unless otherwise specified, the reagents, methods and equipment used in this invention are all conventional reagents, methods and equipment in this technical field.

[0035] Preparation of indium oxide (In₂O₃) powder: Indium ingot (4N₅) was dissolved and dried at room temperature using a chemical precipitation method to obtain indium hydroxide. Indium hydroxide was then calcined at high temperature to form indium oxide powder. The specific surface area of ​​the powder was measured to be within 6 m². 2 / g to 20m 2 Between / g.

[0036] Preparation of tin oxide (SnO2) powder: Tin dioxide powder was prepared by chemical precipitation. The specific surface area of ​​the powder was measured to be within 10 m². 2 / g to 25m 2 Between / g.

[0037] Ga2O3 powder, GaN powder, TiO2 powder: 99.99% purity, commercially available.

[0038] Example 1

[0039] This embodiment provides an IGTO target and its preparation method. The raw materials for preparing the IGTO target consist of the following components by mass fraction:

[0040] 60 parts In₂O₃ powder, 20 parts SnO₂ powder, 17.5 parts Ga₂O₃ powder, 1 part GaN powder, and 1.5 parts TiO₂ powder.

[0041] 1) Mixed granulation:

[0042] In2O3, SnO2, Ga2O3, GaN, TiO2, binder and plasticizer are mixed to obtain a mixed powder, which is then ball-milled and spray-dried to obtain IGTO powder;

[0043] The binder content is 2 wt% of the mixed powder, the plasticizer content is 1 wt% of the mixed powder, the binder is polyvinyl alcohol, and the plasticizer is polyethylene glycol;

[0044] The specific surface area of ​​the obtained IGTO powder is 20 m². 2 / g, the loose density of the obtained IGTO powder is 1.2g / cm³. 3 .

[0045] 2) Compression molding:

[0046] The powder was filled into a 1m×0.5m×0.2m mold, sealed, and then subjected to cold isostatic pressing for 30 minutes at a molding pressure of 150 MPa.

[0047] 3) Degreasing and sintering:

[0048] The preform was placed flat in a sintering furnace, and an inert gas was introduced. The heating rates for the degreasing and sintering stages were set to 2℃ / min and 1℃ / min, respectively. The temperature was raised to 500℃ and held for 2 hours, then raised to 900℃ and held for 2 hours to complete the degreasing process. The temperature was then raised to 1400℃ and held for 4 hours to complete the sintering process. Finally, the furnace was cooled to room temperature to obtain the IGTO sputtering target.

[0049] Example 2

[0050] This embodiment provides an IGTO target and its preparation method. The raw materials for preparing the IGTO target consist of the following components by mass fraction:

[0051] 60.5 parts In₂O₃ powder, 20 parts SnO₂ powder, 17.5 parts Ga₂O₃ powder, 0.5 parts GaN powder, and 1.5 parts TiO₂ powder.

[0052] 1) Mixed granulation:

[0053] In2O3, SnO2, Ga2O3, GaN, TiO2, binder and plasticizer are mixed to obtain a mixed powder, which is then ball-milled and spray-dried to obtain IGTO powder;

[0054] The binder content is 2 wt% of the mixed powder; the plasticizer content is 1 wt% of the mixed powder; the binder is polyvinyl alcohol; the plasticizer is polypropylene glycol;

[0055] The specific surface area of ​​the obtained IGTO powder is 20 m². 2 / g; the loose density of the obtained IGTO powder was 1.2 g / cm³. 3 .

[0056] 2) Compression molding:

[0057] The powder was filled into a 1m×0.5m×0.2m mold, sealed, and then subjected to cold isostatic pressing for 30 minutes at a molding pressure of 150 MPa.

[0058] 3) Degreasing and sintering:

[0059] The preform was placed flat in a sintering furnace, and an inert gas was introduced. The heating rates for the degreasing and sintering stages were set to 2℃ / min and 1℃ / min, respectively. The temperature was raised to 500℃ and held for 2 hours, then raised to 900℃ and held for 3 hours to complete the degreasing process. The temperature was then raised to 1400℃ and held for 5 hours to complete the sintering process. Finally, the furnace was cooled to room temperature to obtain the IGTO sputtering target.

[0060] Example 3

[0061] This embodiment provides an IGTO target and its preparation method. The raw materials for preparing the IGTO target consist of the following components by mass fraction:

[0062] 60.7 parts In₂O₃ powder, 20 parts SnO₂ powder, 17.5 parts Ga₂O₃ powder, 0.3 parts GaN powder, and 1.5 parts TiO₂ powder.

[0063] 1) Mixed granulation:

[0064] In2O3, SnO2, Ga2O3, GaN, TiO2, binder and plasticizer are mixed to obtain a mixed powder, which is then ball-milled and spray-dried to obtain IGTO powder;

[0065] The binder content is 2 wt% of the mixed powder; the plasticizer content is 1 wt% of the mixed powder; the binder is polyvinyl alcohol; the plasticizer is waterborne polyurethane.

[0066] The specific surface area of ​​the obtained IGTO powder is 20 m². 2 / g; the loose density of the obtained IGTO powder was 1.2 g / cm³. 3 .

[0067] 2) Compression molding:

[0068] The powder was filled into a 1m×0.5m×0.2m mold, sealed, and then subjected to cold isostatic pressing for 30 minutes at a molding pressure of 150 MPa.

[0069] 3) Degreasing and sintering:

[0070] The preform was placed flat in a sintering furnace, and an inert gas was introduced. The heating rates for the debinding and sintering stages were set to 2℃ / min and 1℃ / min, respectively. The temperature was raised to 500℃ and held for 2 hours, then raised to 900℃ and held for 3.5 hours to complete the debinding process. The temperature was then raised to 1400℃ and held for 6 hours to complete the sintering process. Finally, the furnace was cooled to room temperature to obtain the IGTO sputtering target.

[0071] Example 4

[0072] This embodiment provides an IGTO target and its preparation method. The raw materials for preparing the IGTO target consist of the following components by mass fraction:

[0073] 60.95 parts In₂O₃ powder, 20 parts SnO₂ powder, 17.5 parts Ga₂O₃ powder, 0.05 parts GaN powder, and 1.5 parts TiO₂ powder.

[0074] 1) Mixed granulation:

[0075] In2O3, SnO2, Ga2O3, GaN, TiO2, binder and plasticizer are mixed to obtain a mixed powder, which is then ball-milled and spray-dried to obtain IGTO powder;

[0076] The binder content is 2 wt% of the mixed powder; the plasticizer content is 1 wt% of the mixed powder; the binder is polyvinyl alcohol and polyacrylic acid; the plasticizer is polyethylene glycol;

[0077] The specific surface area of ​​the obtained IGTO powder is 20 m². 2 / g; the loose density of the obtained IGTO powder was 1.2 g / cm³. 3 .

[0078] 2) Compression molding:

[0079] The powder was filled into a 1m×0.5m×0.2m mold, sealed, and then subjected to cold isostatic pressing for 30 minutes at a molding pressure of 150 MPa.

[0080] 3) Degreasing and sintering:

[0081] The preform was placed flat in a sintering furnace, and an inert gas was introduced. The heating rates for the degreasing and sintering stages were set to 2℃ / min and 1℃ / min, respectively. The temperature was raised to 500℃ and held for 2 hours, then raised to 900℃ and held for 4 hours to complete the degreasing process. The temperature was then raised to 1400℃ and held for 7 hours to complete the sintering process. Finally, the furnace was cooled to room temperature to obtain the IGTO sputtering target.

[0082] Example 5

[0083] This embodiment provides an IGTO target and its preparation method. The only difference between this embodiment and Example 1 is the mass fraction of some of the raw material components: 61.4 parts In2O3 powder, 20 parts SnO2 powder, 17.5 parts Ga2O3 powder, 1 part GaN powder, and 0.1 parts TiO2 powder. The remaining raw material components and preparation method are the same as in Example 1.

[0084] Example 6

[0085] This embodiment provides an IGTO target and its preparation method. The only difference between this embodiment and Example 1 is the mass fraction of some of the raw material components: 61 parts In2O3 powder, 20 parts SnO2 powder, 17.5 parts Ga2O3 powder, 1 part GaN powder, and 0.5 parts TiO2 powder. The remaining raw material components and preparation method are the same as in Example 1.

[0086] Example 7

[0087] This embodiment provides an IGTO target and its preparation method. The only difference between this embodiment and Example 1 is the mass fraction of some of the raw material components: 60.5 parts In2O3 powder, 20 parts SnO2 powder, 17.5 parts Ga2O3 powder, 1 part GaN powder, and 1 part TiO2 powder. The remaining raw material components and preparation method are the same as in Example 1.

[0088] Example 8

[0089] This embodiment provides an IGTO target and its preparation method. The only difference between this embodiment and Example 1 is the mass fraction of some of the raw material components: 59.5 parts In2O3 powder, 20 parts SnO2 powder, 17.5 parts Ga2O3 powder, 1 part GaN powder, and 2 parts TiO2 powder. The remaining raw material components and preparation method are the same as in Example 1.

[0090] Comparative Example 1

[0091] This comparative example provides an IGTO target and its preparation method. The only difference between this comparative example and Example 1 is the mass fraction of some of the raw material components: 60 parts In2O3 powder, 20 parts SnO2 powder, and 20 parts Ga2O3 powder. The remaining raw material components and preparation methods are the same as in Example 1.

[0092] Comparative Example 2

[0093] This comparative example provides an IGTO target and its preparation method. The only difference between this comparative example and Example 1 is the mass fraction of some of the raw material components: 60 parts In2O3 powder, 20 parts SnO2 powder, 18.5 parts Ga2O3 powder, and 1.5 parts TiO2 powder. The remaining raw material components and preparation methods are the same as in Example 1.

[0094] Comparative Example 3

[0095] This comparative example provides an IGTO target and its preparation method. The only difference between this comparative example and Example 1 is the mass fraction of some of the raw material components: 60 parts In2O3 powder, 20 parts SnO2 powder, 19 parts Ga2O3 powder, and 1 part GaN powder. The remaining raw material components and preparation methods are the same as in Example 1.

[0096] Comparative Example 4

[0097] This comparative example provides an IGTO target and its preparation method. The only difference between this comparative example and Example 1 is the mass fraction of some of the raw material components: 60 parts In2O3 powder, 20 parts SnO2 powder, 17.5 parts Ga2O3 powder, and 1 part TiN powder. The remaining raw material components and preparation methods are the same as in Example 1.

[0098] Comparative Example 5

[0099] This comparative example provides an IGTO target and its preparation method. The only difference between this comparative example and Example 1 is the mass fraction of some of the raw material components: 60 parts In2O3 powder, 20 parts SnO2 powder, 17.5 parts Ga2O3 powder, and 1.5 parts TiN powder. The remaining raw material components and preparation method are the same as in Example 1.

[0100] Coating test

[0101] IGTO thin films were deposited on cleaned glass substrates by sputtering at a power density of 1-5 kW / cm². 2 A 40 nm thick film was deposited, and the carrier concentration and mobility of the film were tested. The area ratio of the oxygen vacancy peak (531.6 eV) in the O1s peak was determined using X-ray photoelectron spectroscopy (XPS). The data are shown in Table 1.

[0102] Table 1 Examples 1-8 and Comparative Examples 1-5

[0103]

[0104] As shown in Table 1, 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 sputtered film can be effectively reduced, and the effect on mobility is not significant.

[0105] The present invention has been described in detail above with reference to the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. An IGTO sputtering target material, characterized by, The components include the following mass percentages: The content of In2O3 is 40%~80%, the content of SnO2 is 10%~30%, the content of Ga2O3 is 10%~30%, the content of GaN is 0.1%~1%, and the content of TiO2 is 0.5%~2%, and the sum of its components is 100%.

2. The IGTO sputtering target according to claim 1, characterized in that, The specific surface area of the In2O3 is 6 m 2 / g ~ 20 m 2 / g.

3. The IGTO sputtering target according to claim 1, wherein The specific surface area of the Sn02 is 10 m 2 / g ~ 25 m 2 / g.

4. The method of producing an IGTO sputtering target according to any one of claims 1 to 3, characterized by, Includes the following steps: S1. Mix In2O3, SnO2, Ga2O3, GaN, TiO2, binder and plasticizer to obtain mixed powder, ball mill, and dry to obtain IGTO powder; S2. Press the IGTO powder into a preform to obtain a preform; S3. The preform is degreased, sintered, and cooled to obtain the IGTO sputtering target.

5. The method of claim 4, wherein the IGTO sputtering target is prepared by the steps of: In step S2, the pressure for pressing and molding is 100 MPa to 200 MPa.

6. The method of claim 4, wherein the IGTO sputtering target is prepared by the steps of: The degreasing steps include: heating to 500℃~700℃ and holding for 2h~3h; then raising the temperature to 900~1100℃ and holding for 2h~4h.

7. The method of claim 4, wherein the IGTO sputtering target is prepared by the steps of: The sintering temperature is 1400℃~1600℃.

8. The method of claim 4, wherein the IGTO sputtering target is prepared by the steps of: The sintering time is 4h to 7h.

9. The application of the IGTO sputtering target according to any one of claims 1 to 3 in the preparation of semiconductors.