JPH0280560A - Formation of ito film by sputtering - Google Patents

Abstract

PURPOSE:To control, with high precision, the degree of oxidation of ITO films to be formed on a substrate and to improve the quality of the films by controlling sputter powers by means of emitted light quantity from targets, respectively, at the time of forming ITO films on a substrate by means of a sputtering device in which targets made of In-Sn alloy are used. CONSTITUTION:D.C. power sources 3 are connected to plural In-Sn alloy targets 2 provided to the inside of a vacuum tank 1 and also photoreceiving sensors 4 of a spectral monitoring system for monitoring light emitted from the targets 2 are disposed, and further, sputtering gas-feeding holes 5 are provided to respective side parts of the above sensors 4. Ar as an inert gas and O2 as a reactive gas are supplied through the above feeding holes 5 into the vacuum tank 1 to produce plasmas, and these plasmas are detected by means of the above photoreceiving sensors 4 and fed back to the above D.C. power sources 3, respectively, by which the sputtering powers impressed on the targets 2 can be controlled. By this method, ITO films a1-a4 in which degree of oxidation is lowered toward outside can be formed on the substrate 6, and the ITO films excellent in product yield and improved in transparency can be formed.

Description

[Detailed description of the invention] <Industrial application field> ITO (=In-8
Sputtering production method of n-O=indium stannic acid) WX.

Conventional technology> The conventional method for producing an ITO film (crystalline) is (n: 90[
%], Sn: 10 [%1. In203-dL+5nO was obtained by using IT@-gold with a ratio of
A semitransparent film 2-j is formed. The degree of oxidation at this time is about a, β, and 1n203-. 1+5
n02-. By firing 11 in the air at a temperature of 250-400 CI (or firing in a N2 atmosphere), the oxygen state changes, and the oxidation degrees α and β become close to O, resulting in a transparent I
n20 s-t + S n O2-4, i.e. ITol
forming a l.

In the above example, In-based metal can be used as the target, so the cost is low, and
It is widely used at present because productivity is high because it is fired in a state of

<Problems to be Solved by the Invention> However, in the conventional example described above, since the translucent film is obtained by DC sputtering, when sputtering is applied, hysteresis as shown in Fig. 5 occurs, and the sputtering voltage cannot be kept constant. If the degree of oxidation on the target surface changes even if the target surface is kept constant, the sputtering rate will change, so it is necessary to keep the film quality (degree of oxidation) of the target constant. In order to maintain constant film quality, the electrical and gas systems of the sputtering equipment are controlled with high precision, but the tolerance range for this control is small and it is not easy to obtain the appropriate conditions. Therefore, the yield of the product was low.

Therefore, the present invention aims to solve the drawbacks of the above-mentioned conventional examples, and produces high-quality ITO with easy control of the generation atmosphere.
The purpose is to provide a method by which membranes can be obtained with good yield.

<Means for solving the problem> In an atmosphere consisting of inert gas and oxygen, the sputtering power is controlled while monitoring the amount of light emitted by a spectroscopic monitor system, and the degree of oxidation of the ITO film formed on the tarded is adjusted. By doing so, the degree of oxidation of the ITO film formed on the positive substrate is made smaller toward the outer layer.

<Function> By changing the sputtering power while monitoring the amount of light emitted in the sputtering atmosphere using a spectroscopic monitoring system, the degree of oxidation of the TTO film formed on the glass substrate can be freely changed.

<Example> Hereinafter, the present invention will be described in detail with reference to an example shown in the drawings. First, as shown in FIG. ．．
3... are installed in opposition to each other, and light receiving sensors 4, 4... of a spectroscopic monitoring system for monitoring the luminescence on the target are installed in the vacuum chamber 1, and each tarde 2, 2... On the side, a plurality of sputtering gas supply channels 5.5 are provided to keep the atmospheric gas concentration uniform in each part of the vacuum chamber 1.
... has been established. In order to carry out the method of the present invention using the sputtering apparatus having the above configuration, first, a vacuum chamber is
A mixed gas consisting of an inert gas such as argon gas Ar and a reactive gas such as oxygen is injected from each sputtering gas supply path 5, 5... into the sputtering apparatus.
When the operation is started by applying an operating voltage from the C input power supply device 3.3..., plasma emission is generated between the electrodes in the device, and this is detected by the spectroscopic monitor system 4.
The emitted light energy (emitted light spectrum) at that time is fed back to the DC input power supply device 3.3, and thereby the sputtering power applied to the tarded 2, 2, etc. is controlled.

That is, the relationship between sputtering power and sputtering rate has a hysteresis characteristic as shown in FIG. 3, and each point A on this characteristic
As shown by the positions of l f A 21..., A, even if the six-batter rate changes rapidly, the spectroscopic monitoring system accurately and continuously detects the changes, and the Target sputter input 2.2
. . , the points A, , A, . . . on the glass substrate 6 as shown in FIG.
・TTO films a1・a, with different degrees of oxidation corresponding to ・lA,
...a is formed.

The smaller the sputtering power, the greater the degree of oxidation;
By utilizing the characteristic that the degree of oxidation decreases as the sputtering power increases, the degree of oxidation can be controlled for each ITO film so that it satisfies a, > a, > a3 > a, By firing this, highly transparent ITOWX as shown in FIG. 4 can be obtained.

<Effects of the Invention> The method of the present invention does not have the above-mentioned method; conventionally, as shown in FIG. 3, a point A1. Sputtering was carried out in the region A, but the sputtering power adjustment range was narrow and it was difficult to maintain proper film formation conditions.However, in the present invention, the sputtering rate can be accurately detected using a spectroscopic monitoring system. Therefore, the adjustment range of film forming conditions is widened from A 1 HA 2 + . . . to A4, which improves operability and improves product yield.

In addition, in terms of quality, sputtering atmosphere control can be performed with high accuracy, and as is clear from the characteristic B of the present invention and the conventional characteristic C as shown in Fig. 4, the transmittance after firing was 8.
When 0E%1 or more, the transmittance after sputtering is 65-801
%] (P,,P,), that is, a difference of 15[%], whereas in the present invention, the transmittance after the same firing is 80[%]
In the above case, the transmittance becomes 50 to 8%1 (p,,p,), that is, a difference of 30[%1], which has an effect that the condition width is about twice as large and adjustment is extremely easy.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of a sputtering vacuum apparatus used to carry out the method of the present invention, FIG. 4 is a characteristic diagram of transmittance after sputtering versus transmittance after firing in the present invention, and FIG. 5 is a characteristic diagram of conventional sputtering voltage versus sputtering rate. 1...Vacuum chamber, 2...Tarded 3.
...DC input power supply device 4...Light receiving sensor 6...Plus board

Claims (1)

[Claims] 1. IT (In/Sn) using sputtering vacuum equipment
) or ITO (In, Sn, O) film, the amount of light emitted from the target is monitored by a spectroscopic monitoring system installed in an atmosphere consisting of inert gas and oxygen, and the amount of light emitted is monitored according to the amount of light emitted. ITO characterized by controlling the sputtering power and adjusting the degree of oxidation of the film formed on the target, so that ITO layers with a low degree of oxidation are sequentially formed on a glass substrate from the inner layer to the outer layer. Sputtering production method of film.