JPS62190613A - Manufacture of zinc oxide conductive film - 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 The present invention relates to a method for producing a zinc oxide conductive film among light-transmitting conductive films widely used in solar cells, liquid crystal display panels, and other industries.

Conventional transparent door electrical films include those using thin metals such as Au and those using metal oxides such as 5n02 and Into. Metal thin films have high conductivity, making it easy to create low-resistance films, but they have the drawback of having high absorption in the visible range, making it difficult to obtain high transmittance, and having poor film strength. On the other hand, metal oxides have appropriate conductivity, high transmittance, and excellent film strength, so they are widely used.

Currently, metal oxides known for -S include SnO□ film called Nesa film, InzO film, ITO film, etc. Among these, InzO:+ film and ITO film have a specific resistance of 10 to 4 Ωcm.
Cheng, 5noJ! A modified product with a resistance of about 10 −3 Ωcrn has been obtained.

Furthermore, recently, a zinc oxide film, ZnO, has attracted attention because it has a light transmittance comparable to that of an ITO film and its raw materials are inexpensive.

However, Zn produced by known sputtering method etc.
The O film had a resistivity of only about 10-'' (9 cm) and was not suitable for practical use.

The present invention solves this problem and relates to a method for producing a ZnO film with lower resistance using conventional production equipment as is.

In order to solve this problem, the oxide film is formed by adding a small amount of hydrogen, which is a reducing gas that was conventionally thought to be unnecessary or have a negative effect when creating an oxide film. It is something to do.

EXAMPLES The present invention will now be explained with reference to examples. In this example, a conventionally known agnetron sputtering device was used. 6 inch Zn0 (99,9χ
) Using a sintered target, the distance between the substrate and target is 9
0 mm, Ar was used as an inert gas, the sputtering gas pressure was kept constant at 1.2 Pa, and the applied power was kept constant at 300 -.
A conductive film was prepared. The results are shown in Table 1.

Table 1 For comparison, Z
An nO film was produced. The results are shown in Table 2.

Table 2 In addition, in the substrate temperature column of Table 1 and Table 2, the actual substrate temperature when it is indicated that it is not heated is constant within the range of 30°C to 50°C, although there may be slight differences due to radiant heat during sputtering. As is clear from these Examples and Comparative Examples, it has been found that when a small amount of hydrogen is added when producing a ZnO film, the specific resistance can be improved by two orders of magnitude or more at most. Furthermore, when hydrogen is added, as the substrate temperature is lowered, ZnO
It was found that the resistance value of the membrane decreased. This is completely opposite to the phenomenon when no hydrogen is added.

Further, Table 3 shows typical values of the light transmittance of these ZnO films.

Table 3 (All film thicknesses were 3,000 people) As described above, the transmittance was almost constant regardless of whether hydrogen was added or not, and regardless of the temperature difference, indicating good permeability.

Figure 1 shows the curves (1) (2) that summarize the results in Table 1.
(3) and (4) are respectively 100'C and 100'C without heating at 0'C3.
Corresponds to a substrate temperature of 50°C. As is clear from this, the hydrogen partial pressure ratio exhibits the lowest resistance around 1.5 to 2.5z. Furthermore, at 0°C, even with a hydrogen partial pressure ratio of 10χ, the resistivity value is on the order of 10-' (ΩcII+), and at 0°C without heating the substrate, even with 0.05χ, the resistivity value is 10-'
(0 cm).

In this way, by using a conventional device and adding a small amount of hydrogen, which is a reducing gas, it is possible to form a ZnO film with lower resistance.

Furthermore, it was very effective to maintain the substrate temperature below room temperature and form the ZnO film at this time.

In this example, hydrogen was added to Ar gas using a ZnO target nod; however, hydrogen was added to Ar gas using a Zn target.
The same effect can be obtained even if hydrogen is added during reactive sputtering using two gases.

Also, AI or AI□ can be added to the sputtering target.
A similar result can be obtained even if approximately 1 to 5 wtX of 03 is mixed.

[Brief explanation of drawings]

FIG. 1 shows the relationship between the resistivity of the ZnO film and the hydrogen partial pressure ratio during fabrication.

Claims (1)

[Claims] 1. In a method of sputtering a zinc oxide conductive film using a sputtering target containing zinc or zinc oxide as a main component to produce a zinc oxide conductive film on a predetermined substrate, hydrogen is added to the sputtering gas. , and method 2 for manufacturing a zinc oxide conductive film in which a ZnO film is formed while the substrate is held at a temperature below room temperature, in claim 1, wherein the hydrogen has a partial pressure ratio of 10.0% or less. A method for producing a conductive film of zinc oxide characterized by the addition of