JPH0632309B2 - Electronic component manufacturing method - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a method for manufacturing an electronic component, and more particularly, to a method for forming an oxide on a transparent electrode made of an oxide formed on the surface of an insulating substrate by a sputtering method. The present invention relates to a method of manufacturing an electronic component applicable when forming an insulating layer.

[Background of the Invention]

For example, FIG. 2 shows an example of the structure of a conventional thin film EL element driven by AC. A transparent electrode (IT
O, SnO ₂ etc.) 2 are formed. On top of this, as the first insulating layer 3, SiO ₂ , Al ₂ O ₃ , Y ₂ O ₃ , Ta _{2 is formed.}
A perovskite type oxide such as O ₅ or SrTiO ₃ or a tungsten bronze type oxide such as BaTa ₂ O ₆ having a layer thickness of 0.1 to 1.0 μm is formed by an electron beam evaporation method or a sputtering method. There is. On top of this, Mn, TbF ₃ , SmF ₃ and TmF _{3 are} added as activators.
The light emitting layer 4 made of ZnS to which an appropriate amount of
The layer thickness is about 1.0 μm and is formed by electron beam or sputtering. On top of this, the second
A material similar to that of the first insulating layer 3 is formed as the insulating layer 5, and Al, Au or ITO, SnO is formed thereon.
A back electrode 6 such as ₂ is formed.

In the EL device having such a structure, an AC voltage of about 200 V is applied between the upper and lower electrodes 2 and 6 to obtain EL light emission by the light emitting layer 4. However, since the distance (thickness) between the electrodes 2 and 6 is about 1 μm even if the two insulating layers 2 and 5 and the light emitting layer 4 are combined, a voltage of about 200 V is converted to an electric field strength of 10 ⁶ V. / Cm order, which is a strong electric field at the same level as the dielectric breakdown strength of the insulating layer 2.5 and the light emitting layer 4. Further, since the insulating layers 2 and 5 have a function of a capacitor, that is, a function of accumulating electric charges at the interface of the light emitting layer, a material having a larger relative dielectric constant can efficiently apply an applied voltage to the light emitting layer. Therefore, it is desired to apply a high-quality insulating layer material having a large dielectric breakdown voltage and a large relative dielectric constant.

As such an insulating layer material, the oxide as described above is considered, but a high frequency sputtering method is effective as a method for forming the oxide with high quality. However, as a current problem, if an oxide is formed as the first insulating layer 3 on the transparent electrode 2 by this sputtering method, the electrode is blackened and the light transmittance is lowered, so that it cannot be used as an EL element. It turned out to be a problem. The cause of this is ITO (In ₂ O ₃ + SnO ₂ ) or S which is a transparent electrode.
It is considered that oxygen in nO ₂ escapes during the sputtering and metal In or metal Sn appears. Therefore, for example, a proposal has been made to solve the problem by appropriately controlling the sputtering condition of the insulating layer such as adding a large amount of oxygen, but it is difficult to control the condition, or the insulating film characteristics are not always the best. Nakatsu,
In some cases, the blackening phenomenon cannot be avoided depending on the material. The occurrence of such a blackening phenomenon is pointed out, for example, in Technical Report Vol. 7, No. 34, P. 21 of the Television Society of Japan.

The blackening phenomenon referred to here is a phenomenon in which blackening is visually recognized, and is quantitatively represented by light transmittance. Normally, the transmittance of a transparent electrode such as ITO formed on a glass substrate is 80% or more with respect to light having a wavelength of 580 nm, but if an oxide insulating layer is formed on the transparent electrode by sputtering, the transmittance at that time is increased. Is reduced to 80% or less and a blackening phenomenon occurs.

[Object of the Invention]

The object of the present invention is made under such circumstances, and even if an oxide film formed by the sputtering method is formed as an insulating layer, a blackening phenomenon occurs in a transparent electrode layer made of an oxide. An object of the present invention is to provide a method for manufacturing an electronic member without a problem.

[Outline of Invention]

In order to achieve such an object, the present invention is a method of manufacturing an electronic member, wherein an oxide insulating layer is formed by a sputtering method on a transparent electrode made of an oxide formed on an insulating substrate surface, When performing sputtering, the transparent electrode is held at 0 or a positive potential.

An oxide transparent electrode is formed on the surface of the insulating substrate, and when an oxide insulating layer is formed on this surface by the sputtering method, a potential in the range of -20V to + 50V is applied to the transparent electrode to form each of them. Examining the light transmittance at a wavelength of 5800Å of each transparent electrode of the produced electronic parts, it is found that the results shown in Fig. 1 are obtained. In Fig. 1, the horizontal axis shows the substrate potential with respect to the earth, and the vertical axis shows the light transmittance at a wavelength of 5800Å. As can be seen from this graph, when the substrate potential with respect to ground is 0 V or less,
Light transmittance is 80% or less, and 80% at 0V or more
The above light transmittances are obtained, and the difference in these effects changes stepwise with 0 V as the boundary.

Example of Invention

An embodiment of the method for manufacturing an electronic member according to the present invention will be described below.

Example 1 A SrTiO ₃ sintered body was used as a sputtering target material for forming an insulating layer. Ar as a reaction gas
+ 10% O ₂ is used, the gas pressure is 20 mTorr, and the substrate temperature is 400 ° C.
High-frequency sputtering was performed by changing from V to + 50V. In this way, SrT is formed on the transparent electrode ITO.
After forming an insulating layer of iO ₃ to a thickness of 5000Å, the transmittance was measured. Figure 1 shows the results of plotting the transmittance at a wavelength of 5800Å using the potential with respect to the earth as a parameter. Although the glass transmittance of the substrate is 100%,
When the transmittance is 80% or less, it is visually blackened,
It can be seen that the effect is exhibited when the potential is set to +10 V or more.

Example 2 A SiO ₂ film was formed on ITO by high frequency sputtering. 100% Ar is used as the reaction gas, and the gas pressure is 5
Spattering was performed with mTorr and water cooling of the substrate. In this case, the substrate surface potential was floated with respect to ground. By doing so, a self-bias potential is generated on the substrate surface when a high frequency is applied. According to the measurement, it was found that the bias was about + 20V with respect to the ground.
When SiO ₂ was formed at 2000 Å under these conditions, the transmittance was 9
The blackening phenomenon did not occur at 5%.

In addition, Al ₂ O ₃ , Y ₂ O ₃ , Ta ₂ O ₅ , and BaTa ₂ O ₆
The oxides such as the above were also examined by performing sputtering on the transparent electrode. In any case, the transmittance does not decrease when the surface potential of the transparent electrode is positively biased by +10 V or more. It was

Using the insulating layer manufactured in this way, the light emitting layer Zn
After forming S: Mn by EB vapor deposition, a second insulating layer (the same material as the first insulating layer) and an Al electrode were laminated to manufacture a thin film EL device. As a result, favorable yellow-orange EL emission was obtained.

〔The invention's effect〕

As is clear from the above description, according to the method for manufacturing an electronic member of the present invention, the insulating layer of oxide is formed by the sputtering method on the transparent electrode made of oxide formed on the surface of the insulating substrate. In this case, the blackening phenomenon of the transparent electrode can be prevented.

[Brief description of drawings]

FIG. 1 is a graph showing the effect of one embodiment of the method for manufacturing an electronic member according to the present invention, and FIG. 2 is a sectional view showing the structure of a thin film EL element to which the present invention is applied. 1 ... glass substrate, 2 ... transparent electrode, 3 ... first insulating layer, 4 ... light emitting layer, 5 ... second insulating layer, 6 ... rear electrode.

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Kazuo Taguchi 4026 Kuji Town, Hitachi City, Hitachi, Ibaraki Prefecture, Hitachi Research Institute, Ltd. (72) Kenichi Hashimoto 4026 Kuji Town, Hitachi City, Hitachi, Ibaraki Prefecture Hitachi Research Laboratory (72) Inventor Akira Sato 4026 Kujimachi, Hitachi City, Hitachi, Ibaraki Prefecture Hitachi Research Institute, Ltd. (72) Takahiro Nakayama 4026 Kujicho, Hitachi City, Ibaraki Hitachi Research Institute, Ltd. (72) 72) Inventor Masatoshi Tsuchiya 4026 Kuji Town, Hitachi City, Ibaraki Prefecture Hitachi Research Laboratory, Hitachi Co., Ltd. (56) Reference JP 59-170266 (JP, A) JP 60-221580 (JP, A) Special Kai 61-188892 (JP, A) JP 60-151997 (JP, A) JP 60-170678 (JP, A)

Claims (3)

[Claims] 1. A method for manufacturing an electronic component, wherein an oxide insulating layer is formed on a transparent electrode made of an oxide formed on an insulating substrate surface by a sputtering method, wherein the transparent electrode is used when the sputtering is performed. Is held at 0 or a positive potential, a method of manufacturing an electronic component. 2. The transparent electrode is made of a material made of SnO ₂ , ITO.
The method of manufacturing an electronic component according to claim 1, wherein the electronic component is formed of any of (In ₂ O ₃ —SnO ₂ ) film. 3. The insulating layer is made of SiO ₂ , Al ₂ O ₃ , Y ₂ O ₃ ,
A perovskite type oxide selected from Ta ₂ O ₅ and SrTiO _{3 and} a tungsten bronze type oxide consisting of BaTa ₂ O ₆ are included.
A method of manufacturing an electronic component according to the item.