JPH06120142A - Thin film forming equipment - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide a thin film forming apparatus for forming a uniform thin film on a substrate surface. [Structure] A supply port 8 for supplying a reaction gas into the reaction vessel 1.
The reaction gas is supplied to the surface of the substrate 2 from the vertical direction by disposing the plate 10 having a plurality of plates in parallel and opposite to the substrate 2. Further, the diameter of the supply ports 8 arranged in the plate 10 is reduced in order from the center of the plate 10 to the periphery, or the arrangement density of the supply ports having the same diameter is reduced in order from the center of the plate 10 to the periphery. By adjusting the supply amount of the reaction gas, a flow of the reaction gas maintained at a substantially constant concentration is made from the central portion on the substrate 2 installed corresponding to the central portion of the plate toward the periphery.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film forming apparatus for forming a thin film on the surface of a substrate, and more particularly to a method for supplying a reaction gas to the surface of the substrate.

[0002]

2. Description of the Related Art Conventionally, as a device for forming a thin film on a substrate such as a semiconductor, a lamp heating device (hereinafter referred to as RT
A device) was used.

In this RTA apparatus, as shown in FIG. 4, a sample 2 such as a semiconductor substrate is placed in a reaction vessel 1 in advance,
The reaction gas containing the constituent elements of the thin film material to be formed in the cylinder 5 is supplied from the supply port 8 into the reaction container 1 through the flow rate control valve 6 while the flow rate is monitored by the flow meter 7. Then, the inside of the reaction vessel 1 is efficiently heated by the reflector 4 which reflects heat together with the tungsten halogen lamp 3 to form a thin film on the semiconductor substrate (sample 2).
The gas after completion of this reaction is exhausted from the exhaust port 9.

[0004]

As described above, since the conventional thin film forming apparatus supplies the reaction gas in parallel to the substrate in the reaction container, the concentration of the reaction gas increases as it goes to the exhaust port side. There is a problem that the gas is gradually decreased and the gas having a uniform concentration cannot be supplied to the entire surface of the substrate, so that the film thickness of the thin film formed on the surface of the substrate becomes uneven.

This fact is that a conventional RTA apparatus (FIG. 4) is used to supply a reaction gas of dinitrogen monoxide (N ₂ O) onto the surface of a semiconductor (silicon) substrate at a rate of 2 liters / minute (for the substrate). Supply in parallel, supply concentration is 8.16 mol / min)
However, as a result of forming a silicon dioxide thin film (SiO ₂ ) under the conditions of a reaction temperature of 1100 ° C. and a reaction time of 10 seconds, as shown in FIG. 5, the film thickness near the supply port is about 27 Å, and the film thickness near the exhaust port is about It was confirmed that there was a large difference of about 18 Å in the part.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a thin film forming apparatus for forming a uniform thin film on the surface of a substrate.

[0007]

A thin film forming apparatus according to the present invention is characterized in that a plate having a plurality of supply ports for supplying a reaction gas in a reaction container is installed in parallel to face the entire surface of a substrate.

Further, in this plate, the diameters of the supply ports arranged are reduced in order from the plate center portion to the periphery, or the arrangement density of the supply ports having the same diameter is reduced in order from the plate center portion to the periphery (plate center). The supply amount of the reaction gas is gradually reduced from the part to the periphery).

[0009]

In the thin film forming apparatus of the present invention, the reaction gas is vertically supplied to the surface of the substrate by arranging the plates having a plurality of supply ports in parallel and opposite to the entire surface of the substrate.

Further, the diameter of the supply port arranged on the plate may be reduced in order from the center of the plate to the periphery, or
Alternatively, the density of supply ports having the same diameter is reduced in order from the center of the plate to the periphery to adjust the supply amount of the reaction gas, so that the center of the substrate surface installed corresponding to the center of the plate moves from the center to the periphery. To produce a flow of reaction gas having a substantially constant concentration.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. The same parts are designated by the same reference numerals and the description thereof will be omitted.

FIG. 1 is a block diagram showing an RTA apparatus which is an embodiment of the thin film forming apparatus according to the present invention. This RTA
The apparatus preliminarily sets a sample 2 such as a semiconductor substrate in a reaction container 1, and monitors a flow rate of a reaction gas having a constituent element of a thin film material to be formed in a cylinder 5 by a flow meter 7. It is supplied into the reaction vessel 1 via the flow rate control valve 6. Then, the inside of the reaction container 1 is sufficiently heated by the reflector 4 which reflects heat together with the tungsten halogen lamp 3 to form a thin film on the semiconductor substrate (sample 2) and discharge the gas after the reaction is completed by the conventional RTA apparatus. Is the same as

However, in the RTA apparatus (FIG. 1) according to the present invention, the supply port 8 for supplying the reaction gas into the reaction container 1
The plate 10 having a plurality of is placed parallel to the entire surface of the semiconductor substrate of the sample 2 (the central portion of the substrate is provided so as to correspond to the central portion of the plate), so that it is supplied into the reaction container 1. The generated reaction gas is allowed to flow from the center of the substrate to the periphery thereof, and further, the exhaust port 9 is installed in the periphery of this semiconductor substrate for efficient exhaust.

The plate 10 is constructed, for example, as shown in FIG. 2. The diameter of the supply port 8 is reduced in order from the center to the periphery so that the reaction gas supplied vertically onto the surface of the substrate can be obtained. The supply amount is adjusted (the supply amount is gradually reduced from the center to the periphery). The supply amount of the reaction gas can be adjusted in the same manner by decreasing the arrangement density of the supply ports having the same diameter in order from the central portion to the peripheral portion.

In this embodiment, the diameter of the supply port 8a having a center corresponding to the center of the substrate is 12 mm, and the supply port 8
10 mm, 20 mm, 30 mm from the center of a,
The diameters of the supply ports 8b, 8c, 8d, 8e, 8f, and 8g whose centers are 40 mm, 50 mm, and 60 mm are 3.8 mm, 3.6 mm, 3.4 mm, 3 mm, and 2.
The plate 10 was constructed as 8 mm and 2.2 mm (FIG. 2).

In this embodiment, an RTA apparatus having the structure shown in FIG. 1 is used to apply a reaction gas composed of dinitrogen monoxide (N ₂ O) to the surface of a semiconductor (silicon) substrate at a rate of 2 liters / minute. A silicon dioxide thin film (SiO ₂ ) was formed with a reaction temperature of 1100 ° C. and a reaction time of 10 seconds while supplying it from the upper vertical direction (supply concentration 8.16 mol / min), and the thickness of the obtained thin film was measured by an ellipsometer. did.

As a result, as shown in FIG. 3, the film thickness of the thin film formed on the semiconductor substrate which is the sample 2 can be made substantially constant over the entire surface at approximately 27Å, which is very uniform as compared with the conventional RTA apparatus. It was confirmed that a thin film was obtained.

[0018] In the above embodiment has been described the case of forming a thin oxide film on the semiconductor substrate by supplying dinitrogen monoxide (N ₂ O) as a reaction gas (sample 2), oxygen (O ₂₎ May be supplied to form an oxide thin film, and
The thin film formed on the substrate is not limited to the oxide film.

Further, in the above-mentioned embodiment, an example in which a silicon substrate is used as the sample 2 is shown. However, as the sample 2, even in the semiconductor substrate having an oxide film formed on silicon, a uniform oxide film is formed by dinitrogen monoxide. Can be formed, and is not particularly limited to silicon.

Further, although the tungsten halogen lamp 3 is used as the heating means for the sample 2 in the above embodiment, it is not particularly limited as long as the sample 2 can be heated.

Further, in the above-described embodiment, since the plate 10 is constructed so that the supply amount of the reaction gas supplied from the vertical direction from the central portion of the semiconductor substrate which is the sample 2 to the periphery is sequentially decreased, the diameter of each supply port 8 is reduced. However, the present invention is not particularly limited to this method, and the diameter of the supply ports 8 is the same, and the arrangement density of the supply ports 8 is reduced from the center of the plate 10 to the periphery thereof. However, the same effect is obtained.

[0022]

As described above, according to the present invention, a plate having a plurality of supply ports for supplying a reaction gas in the reaction vessel is arranged so as to be opposed to and parallel to the entire surface of the substrate. The gas is supplied to the substrate surface from the vertical direction, and the plate is arranged so that the diameter of the supply port is reduced in order from the plate center part to the periphery, or the arrangement density of the supply ports having the same diameter is set to the plate center part. From the center of the substrate surface installed corresponding to the center of the plate to the periphery, a reaction gas flow maintained at a substantially constant concentration was created from the center of the substrate surface to the periphery. It has the effect of making it possible to form a uniform thin film.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an RTA apparatus which is an embodiment of a thin film forming apparatus according to the present invention.

FIG. 2 is a configuration diagram of a plate in the RTA apparatus which is an embodiment of the thin film forming apparatus according to the present invention.

FIG. 3 is a diagram showing a thin film formation state by an RTA apparatus which is an embodiment of the thin film formation apparatus according to the present invention.

FIG. 4 is a configuration diagram showing an RTA apparatus as a conventional thin film forming apparatus.

FIG. 5 is a diagram showing a thin film forming state by a conventional thin film forming apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Reaction container, 2 ... Semiconductor substrate, 3 ... Tungsten halogen lamp, 4 ... Reflector, 5 ... Cylinder, 6 ... Flow control valve, 7 ... Flowmeter, 8 ... Supply port, 9 ... Exhaust port, 10 ... Plate.

Claims (3)

[Claims] 1. A reaction gas containing a constituent element of a thin film material to be formed is supplied into a reaction vessel and heated to cause a chemical reaction of the reaction gas, so that a desired substrate is preliminarily placed on the substrate. A thin film forming apparatus for forming a thin film, characterized in that a plate having a plurality of supply ports for supplying a reaction gas in the reaction vessel is installed in parallel and opposite to the entire surface of the substrate. 2. The thin film forming apparatus according to claim 1, wherein the plate is provided with supply ports whose diameters are reduced in order from the center of the plate to the periphery thereof. 3. The thin film forming apparatus according to claim 1, wherein the plate is configured such that the arrangement density of the supply ports having the same diameter is reduced in order from the central portion of the plate to the periphery thereof.