JPS602663A - Production of thin film - Google Patents

Abstract

PURPOSE:To control freely the ZnO/SiO2 ratio of a sputtered film in the stage of forming the sputtered film consisting of ZnO and SiO2 on a base plate by regulating the negative biasing voltage to be impressed on the base plate. CONSTITUTION:A target 23 contg. ZnO and SiO2 and a base plate 24 are placed to face each other and Ar<+> plasma 22 is generated between both by a high frequency power source 21. ZnO and SiO2 are released from the target 23 by the sputtering effect generated when the plasma 22 collides against the target 23, by which a thin film mixed with ZnO and SiO2 is formed on the plate 34. The Ar<+> ion of the plasma 22 in this case is also made incident to the surface of the plate 24 by the negative biasing voltage impressed by a DC power source 26 to sputter again the thin film 25 on the surface of the plate 24. Since the value of ZnO/SiO2 of the film 25 can be freely adjusted by regulating the negative biasing voltage value to be impressed, the film 25 having different ZnO/SiO2 ratios is freely formed with one target.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a method for manufacturing a thin film that makes it possible to obtain a film with an arbitrary mixing ratio of ZnO and 5ift.

(Prior art) Conventionally, when creating a mixed film of 9ZnO and 5i02 using a sputtering apparatus, as shown in FIG.
and 810. It collides with target 12 consisting of
Due to the sputtering effect that occurs, the target material Zn
O, 5in2 is emitted from the target 12, and the substrate 13
A mixed film 14 of ZnO and 5 in 2 is deposited thereon.

At this time, the mixed film 14 of ZnO and 5i02 deposited on the substrate 13 has a relationship with the mixing ratio of the target 12, and in order to create thin films with various mixing ratios (ZnO/StO2), it is necessary to It is necessary to prepare corresponding targets 12, which requires a large amount of cost to prepare a large number of targets, and furthermore, there is a drawback that a large amount of man-hours are required to replace the targets.

(Purpose of the Invention) This invention was made to solve the above-mentioned conventional drawbacks, and it is possible to create a thin film with any mixture ratio from a target with one type of mixture ratio (ZnO/Stow), simplify the number of steps, and An object of the present invention is to provide a method for manufacturing a thin film that can reduce costs.

(Structure of the Invention) The method for producing a thin film of the present invention involves applying a high frequency power source between a target containing zinc oxide and silicon oxide in an arbitrary mixing ratio and a substrate to generate Ar"7' plasma between the substrate and the target. By performing cis battering, zinc oxide and silicon oxide are released from the target to form a mixed thin film of zinc oxide and silicon oxide on the substrate, and the Ar+
The mixed thin film on the substrate is re-sputtered using plasma.

(Example) Hereinafter, an example of the method for manufacturing a thin film of the present invention will be described based on the drawings. FIG. 2 is a diagram showing a sputtering apparatus applied to one implementation. In this Figure 2, 21
is a high frequency power source, one electrode of which is grounded and the other electrode connected to the target 23.

The target 23 is made of ZnO and Sin, and is
Ar+ plasma 22 is generated between the substrate 24 and the target 23, facing the substrate 4. A mixed thin film 25 of ZnO and Sin is formed on the substrate 24.

The substrate 24 is connected to the negative electrode of a DC bias power supply 26 via an inductance element L1, and is grounded via a capacitor C1. The positive electrode of the DC bias power supply 26 is grounded. This inductance element L1 and capacitor C1 are a filter that prevents the high frequency component of the high frequency power supply 21 from being applied to the DC bias voltage.

Next, a method for manufacturing a thin film according to the present invention will be explained using the sputtering apparatus shown in FIG.

In order to form a mixed thin film 25 of ZnO and Sin on the substrate 24, first an Ar+ plasma 22 is generated by the high frequency power source 21. Due to the sputtering effect produced when the Ar+ plasma 21 collides with the target 23, Zn0 and Sin, which are constituent substances of the target 23, are emitted.

Next, the released ZnO and StO are Ar+ plasma 22
After passing through the inside, ZnO and 5i adhere to the surface of the substrate 24.
02 mixed thin film 25 is formed.

Further, the Ar+ ions of the Ar+ ion plasma 21 are also incident on the surface of the substrate 24 due to the negative DC bias voltage 26 applied to the substrate 25, and the mixed thin film (znO/sio) 25 attached to the surface of the substrate 240 is It is emitted again by the sputtering effect. This effect is defined here as a resputter effect.

The rate at which this re-sputtering effect occurs, that is, a certain amount of A
When the r+ plasma 22 is incident on the surface of the substrate 24 with unit energy, the rate at which the thin film constituent material on the substrate surface is re-sputtered varies depending on the material and is unique to that material.

Figure 3 shows the substrate 2 when ZnO is used for the target 23.
4 shows an example of the relationship between the thickness of the ZnO thin film deposited on the surface of No. 40 and the deposition time. As shown in the figure, the rate at which ZnO is deposited is approximately 145,715).

FIG. 4 shows an example of the relationship between StO, film thickness, and deposition time when 5102 is used as a target under the same conditions as in FIG. 3. From the same figure, the speed at which 5i02 adheres is approximately 66 MHz. In FIG. 4, the high frequency power source 21 as a sputtering power source is 13.56 MHz.

The case where a 250W one is used is shown.

As shown in FIGS. 3 and 4, the adhesion ratio of ZnO and SiO□ is dznO/dsiOt=2.2. This value is
When the same energy and the same number of Ar+ plasmas are incident, S
This shows that znO is sputtered 2.2 times more than iO. This relationship also holds true for the resputtering effect performed on the substrate 24.

Furthermore, it is clear that the rate at which the same material is resputtered is proportional to the magnitude of the DC bias voltage applied to the substrate. It is therefore clear that the magnitude of the resputtering effect can be controlled by the bias voltage applied to the substrate.

Thereby, the mixture ratio (ZnO/StOx) of the mixed thin film 25 formed on the substrate 24 can be controlled by the bias voltage applied to the substrate 24.

As described above, in the first embodiment, since the bias voltage applied to the substrate 24 and the mixture ratio (znO/SiO,) of the composite thin film 25 formed on the substrate 24 can be controlled arbitrarily, It has the following advantages:

α) Since the mixture ratio (ZnO/5io2) of the mixed thin film 25 can be controlled by the Kahyas voltage, there is no need to prepare targets 23 for the types of mixture ratios required as in the past, which is advantageous in terms of cost. .

(2) Since it is not necessary to create a target 23 corresponding to the required mixing ratio of the mixed thin film 25, the number of steps required to create the target 23 can be omitted.

(3) The target 23 determines the mixing ratio of the mixed thin film (Zn
In the conventional method in which O/5io2) was determined, the mixing ratio was changed digitally, whereas in the present invention, the mixing ratio can be controlled in an analog manner, making it possible to control the mixing ratio more precisely.

(Effects of the Invention) As described above, according to the thin film manufacturing method of the present invention, a high frequency voltage is applied between the target and the substrate in which zinc oxide and silicon oxide are mixed at an arbitrary mixing ratio, and the target and the substrate are In the meantime, Ar+ plasma is generated, and this plasma releases zinc oxide and silicon oxide from the di-target to form a mixed thin film on the substrate, and the above-mentioned A is applied to this mixed thin film.
Since the re-sputtering is performed using r+ plasma, there is an advantage that a thin film having a desired mixture ratio (ZnO/St 2 O,) can be arbitrarily created from a target having one type of mixture ratio (ZnO/5io2). This allows it to be used in manufacturing processes that require various mixing ratios.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram for explaining a conventional thin film manufacturing method, FIG. 2 is a schematic diagram for explaining an embodiment of the thin film manufacturing method of the present invention, and FIG. 3 is a schematic diagram for explaining an example of the thin film manufacturing method of the present invention. Figure 4 shows an example of the relationship between the thickness of the ZnO thin film that adheres to the substrate surface and the deposition time when the ZnO thin film is deposited on the substrate surface. It is a figure which shows an example of the relationship between thickness and adhesion time. 21...High frequency power supply, 22...Ar+plasma, 2
3...Target, 24...Substrate, 25...Thin film, 26...DC bias voltage. Fig. 1 Fig. 2 Fig. 3 Spantai sun layer clear space (ge) Fig. 4 Suva/Tai sun, opening on the 11th

Claims (2)

[Claims] (1) A high frequency voltage is applied between a target containing zinc oxide and silicon oxide mixed at an arbitrary mixing ratio and a substrate to generate Ar+ plasma between the two, and this Ar+ plasma is used to transfer zinc oxide and oxide from the target. A method for producing a thin film, comprising: releasing silicon to form a mixed thin film of zinc oxide and silicon oxide on the substrate; and re-sputtering the mixed thin film using the Ar+ plasma. (2) The re-sputtering is generated by applying direct current (Iasumi pressure) to the substrate.
2. Method for producing a thin film described in Section 1.