JPH06172994A - Metal oxide sintered body-sputtering target and its production thereof - Google Patents

Abstract

PURPOSE:To suppress abnormal discharge in film formation and to prevent the damage of a target by unevenly distributing a dopant adding part to the target. CONSTITUTION:Two kinds of materials, zinc oxide and a mixture of zinc oxide with a trace quantity of copper oxide dopant are sintered and pulverized. The pulverized materials are classified and packed into a previously prepared vessel 24 for sintering composed of a mold 20 and a partition 22. After that, the partition 22 is removed and the material is pressed and sintered at an adequate temp. Thus, the sputtering target 14 small in resistivity and free from the generation of abnormal discharge caused by charge-up in sputtering is formed. The dopant adding part 10 is unevenly distributed by the shape of kind, and by adding into <30%, preferably <=10% region of whole surface, the resistivity in the residual region is decreased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sputtering target used for forming a high resistance metal oxide thin film, capable of suppressing charge-up and realizing stable discharge, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Recently, a special function sensor using a thin film,
Demand for conductive metal oxide thin films is increasing as electrodes for solar cells and display devices. These thin films are
It is mainly formed by sputtering a metal oxide to which a dopant (a different additive element) is added.

Japanese Patent Laid-Open No. 2-133376 discloses that by mixing and melting a refractory metal-coated Si powder and a refractory metal disilicide powder, the conductivity is excellent, and the surface of the sintered compact target surface during sputtering is excellent. A method for producing a sintered body that can reduce charge-up is described.

Japanese Unexamined Patent Publication (Kokai) No. 3-50148 discloses an extremely excellent low resistance sintering by specifying a ratio of a spinel structure composed of zinc and a dopant element to a wurtzite structure in a zinc oxide sintered body. Getting a body is described. Japanese Patent Laid-Open No. 3-164461 discloses that
Described to produce a zinc oxide sintered body having excellent performance as a sputtering target by increasing the sintering density to a specific range, preventing the airtightness from being contained inside, and fusing the sintered grain boundaries. Has been done.

JP-A-4-6144 discloses that a mixture of a decomposable compound of an element having a valence of three or more and zinc oxide is sintered at a predetermined temperature to suppress fusion of particles. A method for obtaining a high density, low resistance sintered body sputtering target is described. JP-A-4-10493
Japanese Patent Laid-Open Publication No. 7-75 discloses a method of forming a conductive film on a low-temperature substrate by sintering Zn and a coprecipitated oxide of a different element so as to have a predetermined sintered particle diameter and volume resistivity. Has been done.

[0006]

As described above, as described above,
As a method for reducing the resistance value of the target, it is general to devise an optimum dopant material, dopant addition amount, or sintering temperature. Further, conventionally, since the dopant is added to the entire target, abnormal discharge due to charge-up during film formation occurs, which causes a defect in the film or damages the target.

The present invention has been made to solve the above-mentioned problems. By unevenly distributing the dopant addition to the target, the resistance value of the target is reduced, and the charge-up phenomenon of the target surface that occurs during film formation is prevented. It is an object of the present invention to provide a method for producing a metal oxide sintered body sputtering target and a sputtering target that suppress the abnormal discharge, realize stable film formation, and obtain a high-quality film.

[0008]

To achieve the above object, the metal oxide sintered body sputtering target 14 of the present invention has a dopant addition portion 10 and a non-dopant addition portion as shown in FIGS. And a part 12. Figure 1
4 shows an example of uneven distribution of the dopant-added portion 10, other shapes may be used.

[0009] As an example of a metal oxide, if ZnO is used, CuO as dopants, LiCO ₃ or the like is used, CuO, 30% of the total area of the target 14 and LiCO _3, etc. or less, preferably 10% or less By adding only to the area, the remaining area, that is, 70 in area
%, Preferably 90% or more, the resistivity can be lowered. As a result, charge-up that occurs during sputtering is suppressed and stable discharge is realized, so that a high-quality ZnO film can be obtained. In FIGS. 1 to 4, when ZnO is used as the metal oxide, the non-dopant portion 12 is ZnO to which CuO or LiCO ₃ is not added, and the dopant addition portion 10 is CuO.
Alternatively, it is ZnO to which LiCO ₃ is added.

The above-described method for producing a metal oxide sintered body sputtering target is characterized in that the dopant is added only to a part of the metal oxide sintered body to make the dopant unevenly distributed. In this case, the dopant addition amount is made equal to the amount conventionally added to the entire target. As the metal oxide, in addition to ZnO, any metal oxide required to increase the resistance value of the film by doping can be used, and the present invention can be applied to these.

[0011]

EXAMPLE An example of the present invention using ZnO as a metal oxide and CuO as a dopant will be described below with reference to FIG. 5, but the present invention is not limited to the example. is not. Two types of zinc oxide and a mixture of zinc oxide and a trace amount of copper oxide dopant were pre-sintered at appropriate temperatures and then pulverized. Sintering container 24 consisting of mold 20 and cutout 22 prepared in advance
The crushed material was sorted and filled in. Then, the cutout 22 was removed and pressed, and main sintering was performed at an appropriate temperature.
As a result, as shown in the present invention, a sputtering target 14 having a small resistivity and less likely to cause abnormal discharge due to charge-up during sputtering was obtained.

[0012]

Since the present invention is configured as described above, it has the following effects. (1) Since the dopant-added portions are unevenly distributed, the resistance value of the target can be reduced, abnormal discharge can be suppressed during film formation, and defects in the film and damage to the target can be prevented. (2) Not only high frequency sputtering but also film formation by DC sputtering is possible. (3) Special function sensor using thin film (pressure sensor,
Infrared sensor, ultrasonic sensor, etc.) can be applied.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of uneven distribution of dopant addition in a metal oxide sintered body sputtering target of the present invention.

FIG. 2 is a plan view showing another example of uneven distribution of dopant addition in the target of the present invention.

FIG. 3 is a plan view showing another example of uneven distribution of dopant addition in the target of the present invention.

FIG. 4 is a plan view showing still another example of uneven distribution of dopant addition in the target of the present invention.

FIG. 5 is a process explanatory view showing the method of manufacturing the sputtering target in the example of the present invention.

[Explanation of symbols]

 10 Dopant-added part 12 Dopant-non-added part 14 Sputtering target

Claims (2)

[Claims] 1. A metal oxide sintered body sputtering target having a dopant-added part (10) and a non-dopant-added part (12). 2. A method for producing a sputtering target of a metal oxide sintered body, wherein the dopant is unevenly distributed by adding the dopant only to a part of the metal oxide sintered body.