JPH0643631B2 - Gas introduction nozzle for atmospheric pressure CVD - Google Patents

Description

TECHNICAL FIELD The present invention relates to an improvement of a gas introduction nozzle for atmospheric pressure CVD.

[Prior Art] Physical vapor deposition methods, chemical vapor deposition methods, spray methods, dipping methods, and other techniques have been known as methods for forming thin films on the surfaces of glass, metals, and various other substrate materials. It is used properly according to various conditions such as film material and film thickness. Particularly, as a method for forming a film having a film thickness of several hundreds to tens of thousands of angstroms uniformly and with a desired composition, among these, physical vapor deposition and chemical vapor deposition are generally adopted. When the needs for larger substrate size and high productivity on an industrial scale are taken into consideration, the chemical vapor deposition method under normal pressure (hereinafter referred to as normal pressure C
Called VD method) is an effective technique. In the case of industrially producing a large substrate by the atmospheric pressure CVD method, a wide nozzle for introducing a reaction gas and a conveying means such as a belt conveyor or a roller for continuously conveying the substrate are usually provided in the furnace. ,
A method is adopted in which a substrate is transferred into a CVD furnace having a predetermined temperature profile, and a reaction gas is sprayed onto the substrate from a nozzle to form a thin film. When increasing the size of the substrate by such a method, it is conventionally difficult to make the thickness of the film in the substrate uniform.For example, when a conductive tin oxide thin film is formed on a glass substrate, the width is 300 m / m. The film thickness on the substrate was limited to a variation of about ± 10% in the width direction.

[Problems to be Solved by the Invention] The present invention solves the above-mentioned drawbacks of the prior art,
An object of the present invention is to provide a CVD gas introduction nozzle capable of suppressing variations in film thickness.

[Means for Solving Problems] The present inventor has conducted extensive studies as to the cause of nonuniformity of the film thickness in the substrate described above, which occurs when a thin film is formed on the substrate by the atmospheric pressure CVD method. It was found that the non-uniformity of the flow velocity and the flow rate in the width direction of the gas flowing out from the reaction gas introduction nozzle has a great influence, and as a result of efforts to solve such problems, a gas introduction nozzle having a novel structure was invented. Came to do. That is, the present invention relates to a gas introduction nozzle for atmospheric pressure CVD in which a plurality of plates used for forming a thin film on a substrate by an atmospheric pressure CVD method are stacked, and at least one side of the nozzle has all gas supply holes. And a supply plate having a groove for independently dispersing each supplied gas in the width direction is installed, and a single plate or a plurality of plates forming slit-shaped gas discharge holes are laminated on the supply plate. Nozzles are formed, and the stacked plates communicate with the grooves of the supply plate and have elongated holes that form flow paths for independently guiding the gases supplied to the grooves to the discharge holes. Provided is a gas introduction nozzle for atmospheric pressure CVD, which is characterized in that it is provided over substantially the entire width. Hereinafter, the present invention will be described in more detail with reference to the drawings.

The gas introduction nozzle for atmospheric pressure CVD shown in FIGS.
An example of the basic configuration of the nozzle in the case where the gases A, B, and C (each of which is a single component or mixed gas) is discharged from the five-layer slit is shown. 1 is the atmospheric pressure CV shown in FIG.
A sectional view taken along line aa 'of the perspective view of the D gas introduction nozzle 15 is shown. In the figure, 1 and 8 are gas supply plates, 2 and 7 are plates that form a gas C flow path, 3 and 6 are plates that form a gas B flow path, and 4 is a plate that forms a gas A flow path. Reference numeral 5 is a plate for separating the gas A and the gas B. As shown in the drawing, the supply plates 1 and 8 are provided with grooves for supplying gas in the width direction. The supply plates do not necessarily have to be provided on both sides and may be provided on only one side.
Further, as a flow path for each gas, a plate laminated between a supply plate to which the gas is supplied and a plate forming a slit-shaped gas discharge hole for discharging the gas,
As shown in the figure, elongated holes are provided over almost the entire width from which gas is discharged. This elongated hole can be divided into a plurality of parts within a range in which the flow path area is not significantly reduced. It goes without saying that different gases (up to 5 types) can be made to flow through the slits of 5 layers in the illustrated nozzle.

In the present invention, the static pressure difference between the gas supply hole and the discharge hole when the gas is discharged from the nozzle is the maximum difference in the static pressure distribution inside the groove in the supply plate in which the gas flows in the width direction. It is preferably 10 times or more. If it is smaller than this, the distribution of the gas discharge flow rate remarkably occurs in the width direction, which is not preferable. Therefore, the size (width and depth) of the groove existing in the supply plate is increased to increase the static pressure ratio to 10 or more. Is desirable.

Each component of the gas introduction nozzle for atmospheric pressure CVD of the present invention,
It is preferably made of a metal material (for example, SUS etc.) or ceramics which has excellent heat resistance, chemical resistance, physical resistance and durability.

[Operation] The gas flow will be described with reference to the atmospheric pressure CVD gas introduction nozzle illustrated in FIG. In the present invention, the gas introduced from the gas supply hole is supplied to the supply plate 1 as shown in the figure.
Is introduced into a groove provided in the groove and spread in the width direction (in the figure, the gas A component is the uppermost groove, the gas B is the middle groove,
The gas C component is the lower groove). The size of the groove is set so that the maximum difference in the static pressure distribution of each gas in this groove is sufficiently smaller than the pressure difference between the gas supply hole and the discharge hole when the gas is discharged from the nozzle. By defining, the gas is easily spread over the entire width of the groove. The gas thus uniformly spread in the width direction flows through one or a plurality of elongated holes provided in the stacked plates up to the slit through which the gas is discharged. Since the long holes extend over almost the entire discharge width, the uniformity of the gas flow rate spread by the groove of the supply plate is not affected until the plate forming the discharge holes. For example, in the case of focusing on the gas C, as shown in FIG. 3, after passing through the slot provided in the plate 2 forming the flow path of the gas C from the groove provided in the supply plate 1, the slit-shaped discharge hole is formed. Drained from. Further, the plate 2 is provided with elongated holes as flow paths for the gases A and B.

[Effects] According to the atmospheric pressure CVD gas introduction nozzle of the present invention, as described above, the discharge gas is rectified to obtain a uniform gas flow velocity and gas flow rate in the width direction, and a stable gas discharge state is obtained. Therefore, a thin film having a uniform film thickness can be obtained.
The gas introduction nozzle for atmospheric pressure CVD of the present invention is most suitable for an atmospheric pressure CVD apparatus for mass production.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an example of a gas introduction nozzle for atmospheric pressure CVD according to the present invention, FIG. 2 is a perspective view of the gas introduction nozzle for atmospheric pressure CVD shown in FIG. 1, and FIG. 3 is an atmospheric pressure CVD of the present invention. The explanatory view for demonstrating the gas introduction nozzle for use is shown. 1 to 8: plate, 9: atmospheric pressure CVD gas introduction nozzle.

Claims (2)

[Claims] 1. A gas introduction nozzle for atmospheric pressure CVD in which a plurality of plates used for forming a thin film on a substrate by an atmospheric pressure CVD method are laminated, and at least one side of the nozzle is provided with all gas supply holes. A supply plate having a groove for independently distributing each supplied gas in the width direction is installed, and a single plate or a plurality of plates forming slit-shaped gas discharge holes are laminated on the supply plate. The laminated plates are connected to the groove of the supply plate in the stacked plates, and the elongated hole forming the flow path for independently guiding each gas supplied to the groove to the discharge hole is formed in the nozzle. A gas introduction nozzle for atmospheric pressure CVD, which is provided over the entire width. 2. The static pressure difference between the gas supply hole and the discharge hole when the gas is discharged from the nozzle is
The atmospheric pressure CVD gas according to claim 1, wherein the difference is 10 times or more the difference between the maximum value and the minimum value of the static pressure of the gas in the groove for dispersing the gas in the width direction. Introducing nozzle.