JPS61136954A - Indium oxide sintered body - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an indium oxide-based sintered body, particularly an indium oxide-based sintered body suitable as a raw material for producing a transparent conductive film constituting a semiconductor device, etc. .

[Conventional technology]

Transparent conductive films are widely used in transparent electrodes of display devices such as liquid crystal display elements and electroluminescence, electrical barrier films for various parts and gastric compartments, and heaters for preventing freezing on window glass of automobiles and aircraft. ing.

Films of tin oxide and indium oxide have been known as such transparent conductive films. Among them, indium oxide or indium oxide doped with tin oxide (hereinafter referred to as ITO film) is a film with high transmittance and high conductivity that is formed by various thin film forming methods such as sputtering and electron beam evaporation. Widely used.

-For example, the film is deposited by the suctioning technique.

The ITO film will be explained. This is typically done by using an indium tin alloy or an indium tin oxide sintered body as a vapor deposition base material (hereinafter referred to as TARDAT) and sintering it in an argon gas atmosphere or an argon + oxygen gas atmosphere. Filmed. At this time, in order to improve the conductivity and transmittance of the ITO film, it is known to perform substrate heating or after-annealing as necessary. When forming an ITO film by a method such as tin, tuttering, or electron beam evaporation, if an indium oxide sintered body is used as the evaporation base material, the following problems may occur if the sintered body has poor sinterability. arise.

(2) It is easy to store gas inside the sintered body, and in a vacuum, Vclf gas is gradually released, reducing the degree of vacuum in the device chamber.

- A part of the sintered body is easily scattered by external impact such as plasma or electron beam and mixed into the ZTO film.

■ The mechanical strength of the sintered body is low and it is easily damaged by thermal distortion.

■ indicates a decrease in the electrical properties of the membrane, ■ indicates the occurrence of defects in the membrane, ■
This may cause damage to the deposition substrate, resulting in decreased productivity.

[Problems to be solved by the invention]

The present invention addresses the problems associated with conventional indium oxide sintered bodies, such as gas occlusion, impact fracture, and poor mechanical strength due to sintering failure
In addition to solving problems such as damage caused by thermal strain, 1. Eliminating film defects especially when used as a raw material for transparent conductive films.
This was done with the aim of maintaining and improving electrical and optical properties and improving productivity of film formation.

[Means for solving problems]

That is, the indium oxide-based sintered body of the present invention, which has been found to solve the above problems, contains S in addition to In and 0.
It is characterized by containing t and/or Ge as essential constituent atoms.

[Detailed description and examples of the invention]

Electrical conduction in an indium oxide film or an ITO film is
As an n-type semiconductor, conduction is mainly caused by electrons,
It is assumed that electrons as carriers are generated by oxygen defects or doped tin. Therefore, in order to improve the sinterability of insium oxide-based sintered bodies, it is necessary to maintain the above-mentioned electrical conduction mechanism. We have discovered Si and Ge as additional components that satisfy both the requirements of maintenance and expression.

The indium oxide-based sintered body of the present invention has In, 0 and S
For example, In2O3-5, which has only i and/or Ge as constituent atoms and can be used mainly as a starting material for an indium oxide film.
i02 series, In2O3-G@02 series, In2O3-8i
02- GeO2 system, In2O3-Si system, In2O3
-Ge series, In2O3-Si -Ge series, etc. sintered bodies,
An example of tf that has constituent atoms of In, 01Sn, St and/or Ge and can be used as a starting material for an ITO film.
In20. -8n02-5102 series, In2O3-5n
02- GeO2-based, Ir2O3-8n02-5i02
- GeO2 series, In2O3-5n02-81 series, In
2O3-5n02-Ge system, In20. -5n02-
Si-G.

This includes sintered bodies such as systems. In addition, these In-8i-G
Other constituent atoms in the e-0 system and the In-Sn-Si-Ge-0 system include atoms of oxygen group elements such as S, Ss, and Te, s Fs C1% Br % Halodane atoms of I, B, hi Atoms of group 3 elements in %G&%rl, N, P.

Atoms of Group 5 elements such as As, Sb, and Bi can be added in amounts within a range that does not impair the object of the present invention.

Below, we will focus on indium oxide-based sintered bodies containing In, OsSn, and St and/or Ge as constituent atoms, which can be used as starting materials for ITO films that have high utility as light-transmitting conductive films. The present invention will be explained in more detail.

The starting material for In constituting the indium oxide sintered body of the present invention is generally In2O3, but of course In
It is also possible to use In alone, hydroxide, chloride, nitrate, sulfate, etc. of In. When using a starting material other than an oxide, it may be converted into an oxide form during the calcination or sintering process in an oxygen-containing atmosphere and then injected into the sintered body.
Alternatively, it may be partially incorporated into the sintered body in the form of each starting material such as In.

The starting material for Sn is generally an oxide such as 5n02, but it is also possible to use Sn alone, Sn hydroxide, chloride, nitrate, sulfate, etc. As in the case of In, the starting materials other than the KXe compound may be changed into oxides in advance and injected into the sintered body, or they may be partially injected into the sintered body as they are in the form of Sn, etc. good.

As a starting material for St, oxides such as 5io2 are generally used, but simple St, hydroxide of St, etc. can also be used. As in the case of In, starting materials other than monooxide may be changed into oxides in advance and injected into the sintered body, or they may be partially injected into the sintered body in the form of St, etc. For example, In20. -5n02-5i02-
A sintered body of Si type or the like can be formed.

As a starting material for Ge, oxides such as G502 and G@0 are generally used, but it is also possible to use simple Ge, hydroxides, chlorides, etc. of Ge. Busy as in the case of In,
Starting materials other than oxides may be changed into oxides in advance and injected into the sintered body, or they may be partially injected into the sintered body in the form of Ge, etc., for example, In2O3-5n.
02- A sintered body of GaO2-G@ system etc. can be formed.

Si and G constituting the indium oxide-based sintered body of the present invention
e is, for example, a solid solution with In2O3 (In1-.
81. )203 (0<a<1), (In1-1.G
sb) zos (o<bku1), (IJ-6-dSic
Ged) 203 (0<e<1, o(d(i)(
The solid solubility limit of 5102 and GaO2 in In2O3 is about 10 to 20 times 5to2, respectively! #-1G・02 is thought to be in the range of about 10 to 20% by weight. ), In
For example, (In1-,
-fSn, 81f) 203(0(e(1,0<f<1
), (In1-, -hSn, Gsh)203 (o<
g<1.0(h(1), (In1-1-j-kSniS
ijGek) (0<1×1.0<j<1, O<k<
1) (The solid solubility limit of 5n02 in In203ic is thought to be in the range of about 10 to 20% by weight of 5n02.), complex oxides such as In2Ge207, 5i02
, GeO2, Geo, 511G@, etc., in the form of starting materials.

The content of Si and/or G in the indicium oxide sintered body of the present invention is 0.0001 to 0 per mole of In.
．． 6 mol is preferred. This is because if it is within this range, the density and mobility of carrier electrons can be appropriately controlled to maintain conductivity within a good range.If it is less than 0,0001 mol, the carrier electron density will not reach the desired value. This is because if the amount exceeds 0.6 mol, the carrier mobility decreases and the conductivity deteriorates. In the case of Si, the more preferred content is 0.01 to 0.3 mol, more preferably 0.02 to 0.1 mol, per 1 mol of In. The amount is 0.01 to 0.3 mol, more preferably 0.02 to 0.1 mol.

In addition, the content of Sn is 0.001 to 1 mole of In.
0.3 mol is preferred. The reason is that if it is within this range,
In order to maintain conductivity within a good range by appropriately controlling the density and mobility of carrier electrons, 0.001
9. If it is less than molar, the carrier electron density is small.
This is because if the amount exceeds 0.3 mol, the mobility of carrier electrons will be lowered and the conductivity will be deteriorated.

A more preferable content of Sn is 0.0 per mole of In.
1-0.15 mol, more preferably 0.05-0.1 mol.

The indium oxide-based sintered body of the present invention can be produced by mixing the powders of the starting materials described above and compressing them at room temperature to obtain a green compact, which is then calcined if necessary, and then fired. However, in the case of the present invention, the powder compact is simply subjected to a firing process by subjecting it to a single high temperature. It is possible to obtain a sintered body of. The firing temperature can be selected as appropriate depending on the composition of the desired sintered body, but it is usually 14°C.
00~1500℃, and the atmosphere used for firing is:
For example air atmosphere containing oxygen, 02 and CO1co2
, N2, Ar s H2, H2Os, etc., an oxygen-free atmosphere such as a vacuum, or an atmosphere of Ar, N2, etc. may be used. In addition, by adjusting the oxygen partial pressure in the atmosphere used, the amount of oxygen defects can be controlled, and the carrier density and thus the conductivity of the sintered body can be controlled. By introducing a reducing gas such as CO, the conductivity of the sintered body can be controlled by controlling the amount of oxygen vacancies.

The shape of the indium oxide-based sintered body of the present invention is appropriately selected depending on the purpose of use. For example, when it is used for a tar duct for a square ring for forming an ITO film, it usually has dimensions such as 127 x 381 x 6 (dragon). It is formed into a shape such as a rectangular flat plate.

Further, when used for electron beam evaporation, it is usually formed into a shape such as a pellet shape having dimensions of, for example, 20φx 10 (w).

Example 1 rn205.5n02 and 5i with purity of 99.99 or higher
Using each powder of o2, the content of 5n02 in the mixed powder was fixed at 5 weight cIIVc, and the rest was In2O3 and 5102.
Several kinds of mixed powders were prepared at arbitrary mixing ratios, and each mixed powder was heated to a pressure of 500 kl! / eyll'' was press-formed and fired in air at 1450℃ for 2 hours to form a disc-shaped ITO with a diameter of 100m and a thickness of 5sm.
A sintered body for film formation was obtained.

The relative densities of these sintered bodies were measured, and the results are shown as a curve IK in FIG. 1, with the horizontal axis representing the Si content and the vertical axis representing the relative density.

Further, the resistivity of the obtained sintered body was measured, and the results are shown in curve 2 in FIG. 2, with Si content on the horizontal axis and resistivity on the vertical axis.

Next, these sintered bodies were used as targets in a high-frequency magnetron snogging device, and sputtering was performed under the following conditions to produce a transparent conductive film.

Note: The sintered target thus used released less gas during evacuation, and it took less than 5 minutes to evacuation to 10 Torr. In addition, the mechanical strength was increased, and there was no damage during snow or stumbling. Furthermore, no trace of sintered bodies being mixed into the formed ITO film was observed. The resistance value of the film is 5 to 6 x 10Ω, which is the same level as the ITO film that does not contain 5102.Also, when we measured the translucency, it showed a transmission of 90% or higher in the visible light range. The rate was shown.

Example 2 Example 1 except that 5102 #) Ic Si was used
A sintered body was prepared in the same manner as above, and then a ZTO film was formed.

The relative density and resistivity of the sintered body thus obtained were equivalent to curve 1 in FIG. 1 and curve 2 in FIG. 2. Examples may be added after filing Example 3 Sintering was carried out in the same manner as Example 1 except that PC81/SiO2 mixed powder was used and the sintering atmosphere was an atmosphere in which the partial pressure of oxygen could be adjusted. A body was prepared, and then an ITO film was prepared.

The sinterability of the sintered body thus obtained and the conductivity of the sintered body were as good as in Example 1.

Example 4 A sintered body was produced in the same manner as in Example 1 except that GeO2 was used instead of S102, and then a transparent conductive film was produced.

Relative density of the sintered body thus obtained (curve 1 in Figure 1)
The specific resistance of the sintered body (curve 2 in FIG. 2) was as good as in Example 1.

〔Effect of the invention〕

According to the present invention, sinterability is significantly improved compared to conventional indium oxide-based sintered bodies, and disadvantages such as gas occlusion, 48 fracture, poor mechanical strength, and damage due to thermal strain do not occur. In particular, it is expected that when used as a raw material for transparent conductive films such as S.9-notaring particles, film defects will be eliminated, the electrical and optical properties of the film will be maintained and improved, and the productivity of film formation will be improved. An effect that does not occur is produced.

[Brief explanation of drawings]

Figure 1 shows the relative density of the indium oxide-based sintered body of the present invention,
FIG. 2 is a curve diagram showing the specific resistance of this sintered body. Figure 1 In f7ru tO writing Si mistake 1 ↓ G's 71 shi 4 Figure 2 In1 71shi; Literary talent S1 or 1 blind Ge 7ru summer procedure amendment signed) January 1985 Manabu Shiga, Director General of the Patent Office on the 23rd 1 Display of the case Patent Application No. 256566 of 1982? Name of the invention Indium oxide-based sintered body 3 Relationship to the case of the person making the amendment Patent applicant address 2-1-1 Nihonbashi Muromachi, Chuo-ku, Tokyo Name
(618) Mitsui Kinzoku Mining Co., Ltd. Representative Ko Mashima 3rd Department 4 Agent 105 Claims column of the specification and Detailed explanation of the invention column 6 Contents of amendment (1) Amendment of the patent claims of the specification Correct the range column as shown in the attached sheet. (2) In the bottom line of page 11 of the specification, “...Measure specific resistance,
``Fist...'' is changed to ``0...Measure the specific resistance, fist...''. (3) Change “On line 2...” to “Line 1” on page 12 of the specification, line 2.
To...''. (4) “e-・Curve 2 in Figure 2” on page 13, line 9 of the specification
is defined as "-...Curve 1 in Figure 2". (5) Delete "Examples may be added after filing" on page 13, lines 10-11 of the specification. (6) "Curve 1)...Φ" on page 14, line 5 of the specification shall be changed to "Curve 2)...1". Claims (1) An indium oxide-based sintered body characterized by containing Sf and/or Ge as essential constituent atoms in addition to In and O. (2) Contains Sn as a constituent atom together with In, O, and Si and/or Ge, and contains St and/or Ge
The content of Sn is 0.0001 to 0.6 mol with respect to 1 mol of In, and the content of Sn is 0.001 to 0.3 with respect to 1 mol of In.
The fermented indium-based sintered body according to claim (1), which is a molar amount. (3) An indium oxide-based sintered body according to claim (1) or (2), in which silicon oxide is used as a starting material for Si. (4) The indium oxide-based sintered body according to any one of claims (1) to (3), in which germanium oxide is used as a starting material for Ge.

Claims (4)

[Claims] (1) An indium oxide-based sintered body characterized by containing Si and/or Ge as essential constituent atoms in addition to In and O. (2) Along with In, O and Si and/or Ge, Sn
as a constituent atom, the content of Sn and/or Ge is 0.0001 to 0.6 mol per mol of In, and the content of Sn is 0.001 to 0.3 mol per mol of In. The indium oxide-based sintered body according to the range (1). (3) An indium oxide-based sintered body according to claim (1) or (2), in which silicon oxide is used as a starting material for Si. (4) The indium oxide-based sintered body according to any one of claims (1) to (3), in which germanium oxide is used as a starting material for Ge.