JPH01313926A - Vertical type plasma cvd device - Google Patents

Abstract

PURPOSE:To shorten the time of the temperature rise of a substrate while equalizing temperature distribution by casting a metallic wire or a metallic band generating heat by conduction into a heat transfer metallic material and constituting a susceptor as a massive heating element with both parallel surfaces on which the substrates are fixed. CONSTITUTION:A sheathed heater 14 is wound in a coil shape and formed so as to obtain a specified resistance value, the sheathed heater 14 is buried in an insulated state from a pipe through aluminum oxide powder into a stainless pipe, and the end sections of nichrome wires are insulated from the stainless pipe at both end sections of the pipe while the end sections of the pipe are sealed in an approximately airtignt manner. A pipe heat source in which a terminal 14a is provided is made to wind repeatedly in parallel to form a heat-generating section, the snaking pipy heat source, the sheathed heater 14, is buried into the ingot 15 of aluminum, and a susceptor 20 is organized as a flat square box-shaped massive heating element. Accordingly, the heating efficiency of the susceptor 20, which must transfer heat to a substrate 4, is improved remarkably, the time of the temperature rise of the substrate is shortened largely, and the temperature distribution on a heating surface is equalized approximately completely.

Description

[Detailed Description of the Invention] [Industrial Applications] This invention relates to a vertical plasma CVD apparatus that forms a film with the surface of the substrate to be filmed vertically. A susceptor is provided with a heating element between the vertical surfaces on which the substrates on which thin films are to be formed are closely fixed.
The present invention relates to a temperature increasing structure of the susceptor in a vertical plasma CVD apparatus that sequentially moves between adjacent film forming chambers in which film formation by plasma CVD is performed to sequentially form new thin films in multiple layers on the substrate. .

[Conventional technology]

FIG. 4 shows an example of the structure of a conventional susceptor. The bases Fi4, which are fixed in close contact with the outer surfaces of the metal plates 2, which are parallel to each other with their surfaces facing vertically and are connected via a coupling member 2a having a U-shaped upper edge, are heated from the back side. A plurality of rod-shaped infrared lamps 3 for raising the temperature are arranged horizontally between the opposing surfaces of the metal plate 2 and at intervals in the vertical direction as shown in FIG. The portion is connected to a strip-shaped terminal plate that is supplied with power from outside the film forming chamber 1 (FIG. 4). In addition, in FIGS. 4 and 5, the reference numeral 2b
is a bent edge formed above the center side of the U-shaped coupling member 2a and integrally with the side, and is freely rotatable around a horizontal axis arranged perpendicular to the plane of the paper on the side of the film forming chamber. The roller 2C is suspended by a roller 2C, and is engaged with a transport device (not shown) disposed at the elongated opening 1a of the film forming chamber 1 across the upper space 1b and the film forming space 1c, and receives a moving force perpendicular to the plane of the paper.

[Problem to be solved by the invention]

The problems with the temperature raising structure of the susceptor constructed in this way are as follows. In other words, metal plates 2 facing parallel to each other
When a metal material such as aluminum or stainless steel is used, the gloss of the metal surface has a high reflectance of infrared rays, and even if the capacity and number of infrared lamps are increased, the temperature does not rise easily, making it difficult for the board to reach the desired temperature. It takes a long time to complete the process, and the time interval between film-forming processes, or takt time, becomes long, which hinders the productivity of semiconductor manufacturing, where the time required to form a thin film accounts for a large proportion of the total manufacturing process time. There was a problem. Moreover, it is extremely difficult to equalize the temperature distribution in the space facing the metal plate 2 due to the spacing of the infrared lamps and differences in local reflectance on the surface of the metal material. The distribution becomes non-uniform, making it difficult to form a uniform IIQ thickness using conventional plasma CVD equipment.

An object of the present invention is to be able to shorten the heating time of a substrate and to make the temperature distribution uniform. An object of the present invention is to provide a vertical plasma CVD apparatus having a susceptor with a simplified temperature raising structure.

[Means to solve the problem]

In order to solve the above problems, according to the present invention, a susceptor is provided with a heating element between vertical surfaces facing in parallel and on which substrates on which thin films are to be formed are closely fixed. By energizing the susceptor in a vertical plasma CVD apparatus, the susceptor is sequentially moved between adjacent film forming chambers in which film formation is performed by the plasma CVD method to sequentially form new thin films in multiple layers on the substrate. The heat-generating metal wire or band is cast into a heat-conductive metal material, and the heat-generating body is constructed as a block-like heat-generating body having parallel surfaces to which the substrate is fixedly attached.

[Effect]

By configuring the susceptor in this way, all of the heat energy supplied from an external power source to the metal wire or metal strip as a heating element is transferred to the heat conductive metal material into which it is cast, and the heat should be transferred to the substrate. The heating efficiency of the susceptor is significantly increased. Moreover, the heat conductive metal material into which metal wires and metal strips are cast has a thicker wall along the surface direction of the heat transfer surface to the substrate, so the metal wires and metal strips reciprocate in parallel at intervals. Even if it forms a meandering heating area while manipulating the
As it approaches the heat transfer surface, the non-uniformity of the temperature distribution is quickly smoothed out, and the in-plane temperature distribution becomes uniform at the heat transfer surface.

〔Example〕

An embodiment of the present invention is shown in FIGS. 1 and 2. FIG.

In the figure, the same members as in FIGS. 4 and 5 are denoted by the same reference numerals, and explanations thereof will be omitted. Inside the film forming chamber 1, there is an electric scraping plate 11 facing parallel to the substrate 4 on which a thin film is to be formed, and converting the film forming raw material gas introduced into the film forming chamber 1 into plasma in the opposing space.
is supported in an insulating state on the inner wall of the film forming chamber 1 via an insulating support member 12, and is drawn out from the film forming chamber 1 in an insulating state via an insulating cylinder 13, and the frequency is normally 13°56 MH2.
It is connected to a high frequency type tA19 having a radio frequency of .

By the way, the susceptor 20, which is suspended from a roller 6 above the film forming chamber and is conveyed in a direction perpendicular to the plane of the paper in FIG. This is wrapped into a shape to form a predetermined resistance value, and it is embedded in a stainless steel pipe insulated from the pipe through aluminum oxide powder, which is a heat-resistant material. The end of the pipe is almost hermetically sealed. A pipe-shaped heat source provided with a lead-out terminal 14a equipped with a sealing member made of ceramics is meandered repeatedly in parallel to form a heat generating area, and this meandering pipe-shaped heat source, that is, the sheathed heater 14, is made of aluminum, which is a good conductor of heat. It is constructed as a flat, rectangular box-shaped block heating element that is embedded in the inboard (15).

A fixing part 15a is formed below the ingot 15 for fixing the pull-out terminal 14a of the sheathed heater 14 to the ingot 15 in an insulated state,
A sliding contact surface formed using a flexible conductive plate on the top of the bushing 16 is brought into contact with a pull-out terminal 14a of the sheathed heater. A thermostat 17 is further attached to the side of the ingot 15, and it is possible to read the temperature of the ingot 15 from outside the film forming chamber 1 and adjust the output of the heating electric current #18 of the ingot 15 according to the read temperature.
An external control system (not shown) is configured. In the figure, reference numeral 21 denotes a vacuum pump, which serves to maintain the inside of the film forming chamber I at a predetermined vacuum pressure while evacuating the film forming raw material gas introduced into the film forming chamber 1.

When the susceptor 20 is configured in this way, the sheathed heater 1
The thickness T of the ingot 15 from the heat-generating area formed in a planar shape by meandering repeatedly in parallel to the heat transfer surface to the substrate 4 increases, and the uneven temperature distribution in the vertical direction of the paper at the heat-generating area is due to heat transfer. It becomes smaller as it approaches the surface, and on the heat transfer surface, the in-plane temperature distribution becomes almost completely uniform.

FIG. 3 is a front view of a vertical plasma CVD apparatus in which the susceptor 20 configured as described above moves.

The susceptor 20 suspended from a roller row in which rollers 6 are arranged at intervals in the horizontal direction is moved in the direction of the arrow by a transport drive mechanism (not shown) after the film formation is completed in the film formation chamber l at the front stage, and is moved to the direction of the arrow to carry out the film formation at the rear stage. When the film enters the film chamber 1 and reaches a predetermined position in the film forming chamber 1, the pull-out terminal 14a of the sheathed heater protruding from the fixed part 15a below the ingot 15 is connected to the film forming chamber 1.
A sliding contact surface formed using a flexible conductive plate on the top of the side bushing 16 (FIG. 1) is brought into sliding contact without bending the conductive plate, and is connected to the heating electric current mt8. Also, although not particularly shown here, thermostat 17 (second
2) also comes into contact with the contact surface of the external lead terminal provided in the film forming chamber 1 at this position, and is connected to an external temperature control system. In addition, in plasma CVD equipment, usually 0.1 to 1oOT
Films are often formed under gas pressures in the .
The device is configured such that current is supplied to the device by stepping down the voltage using a transformer 18a. In addition, in Figure 3, 2
2 is an exhaust pipe connected to the intake side of a vacuum pump 21 (FIG. 1), and 23 is a level adjuster for leveling the film forming chamber 1 and adjusting the height of the film forming chamber 1.

〔Effect of the invention〕

As described above, according to the present invention, a susceptor is provided with a heating element between vertical surfaces facing in parallel and on which substrates on which thin films are to be formed are closely fixed, In a vertical plasma CVD apparatus, the susceptor is sequentially moved between adjacent film forming chambers in which films are formed by the plasma CVD method, and new thin films are sequentially formed in multiple layers on the substrate. The heating element is constructed by casting a metal wire or band into a heat conductive metal material and having parallel surfaces on which the substrate is fixed.
All of the heating energy supplied from the power source to the metal wire or metal strip is transferred to the heat-conductive metal material into which they are cast, significantly increasing the heating efficiency of the susceptor that transfers heat to the substrate, and significantly reducing the time required to heat up the substrate. It is shortened to . Therefore, the time interval between film-forming processes, that is, the takt time, is greatly shortened, and the productivity of semiconductor manufacturing, in which the time for thin-film formation occupies a large proportion of the total manufacturing process time, is greatly improved. In addition, since the susceptor constitutes a bulk heating element, the wall thickness from the heat generating part to the heat transfer surface to the substrate is thick, and the uneven temperature distribution within the plane including the heat generating part becomes smaller as it approaches the heat transfer surface. The in-plane temperature distribution on the heat transfer surface becomes almost completely uniform.

As a result, uneven film thickness due to uneven temperature distribution, which could not be avoided with conventional susceptor heating structures, can be avoided, making it possible to form thin films with highly uniform film thickness and, therefore, film quality. . Moreover, the temperature increasing structure according to the present invention is simpler, more robust, and more economical than conventional ones.

It also has the advantage of being easy to maintain against surface stains.

[Brief explanation of the drawing]

FIG. 1 is an explanatory sectional view of an example of a vertical plasma CVD apparatus equipped with a susceptor having a temperature increasing structure according to an embodiment of the present invention, and FIG. 2 is a front view showing the configuration of heat generating parts in the susceptor shown in FIG. 1. FIG. 3'' is a front view showing the overall configuration of the vertical plasma CVD apparatus in which the susceptor shown in FIGS. 1 and 2 moves;
Figure 4 is a cross-sectional view of a film forming chamber showing how the susceptor is used and the temperature increasing structure of a conventional susceptor, and Figure 5 shows details of the temperature increasing structure of a conventional susceptor. )
is a front view, and is a side view. ■...Film forming chamber, 2...Metal plate, 4...Substrate, 14
...Sheathed heater (metal wire or metal band), 15...
・Ingot (thermal conductive metal material), 18... heating power source,
20...Sasepu 1 Figure 3 Figure 4 (2) '5-5 Figure C4) 4'J'1

Claims (1)

[Claims] 1) A susceptor equipped with a heating element is placed between the vertical surfaces of which the substrates on which thin films are to be formed are fixed in close contact with each other, and the substrates face each other in parallel, and the film is formed inside the susceptor by the plasma CVD method. In a vertical plasma CVD apparatus that sequentially moves between film forming chambers where new thin films are sequentially formed on the substrate in multiple layers, the susceptor connects a metal wire or metal band that generates heat when energized to a heat conductive metal material. A vertical plasma CVD apparatus characterized in that it constitutes a bulk heating element having parallel surfaces, into which the substrate is fixed by being cast.