JP2001358078A - Film forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film forming device capable of protecting heat-resistant glass fitted in a lamp window against cracking. SOLUTION: This film forming device has the same structure as a usual film forming device except that quartz glass has a different constitution, and annular packing is interposed between the peripheral edge of the quartz glass and the opening wall of the lamp window. The quartz glass 40 is a disk-shaped quartz glass member and comprises a circular center region 42 on its chamber- side surface and an annular peripheral region 44 around the center region 42, where the center region 42 is formed around the peripheral region 44, protruding from the region 44 toward a chamber and making a level of difference with the region 4. The packing 48 is formed like a ring along the peripheral edge of the quartz glass 40, made of Teflon (registered trademark) smaller in rigidity than the quartz glass 40, composed of a frame 50 surrounding the center region 42 of the quartz glass 40 and a skirt 52 extending from the outer edge of the frame 50 in a direction vertical to the edge, and has the shape of an inverted L in cross section. The skirt 52 is equipped with a tapered tip 54 decreasing in thickness toward the tip.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film forming apparatus for forming a predetermined film on a wafer in a process of manufacturing a semiconductor device, and more particularly, to a film forming apparatus fitted in a lamp window provided in a film forming chamber. The present invention relates to a film forming apparatus configured so that quartz glass is not damaged.

[0002]

2. Description of the Related Art In the process of manufacturing a semiconductor device, a predetermined film such as an insulating film or a semiconductor film is often formed on a substrate by using a film forming apparatus. In the film forming process, various types of film forming apparatuses are used, and as one of them, a decompression / heating type film forming apparatus is frequently used. Decompression / heating type film forming equipment
A film forming chamber for holding a wafer inside under reduced pressure, and a lamp heating device for heating the wafer in the film forming chamber are provided, and quartz glass fitted in a lamp window provided by opening a chamber wall of the film forming chamber is provided. While the wafer in the film forming chamber is heated by the lamp heating device through the intermediary, a reaction gas is introduced into the film forming chamber to form a predetermined film such as a semiconductor film and an insulating film on the wafer.

Here, the configuration of a conventional decompression / heating type film forming apparatus will be described with reference to FIG. 4 and FIG. FIG.
FIG. 5 is a schematic cross-sectional view showing a configuration of a heating type film forming apparatus, and FIG. 5 is an enlarged cross-sectional view of a portion A in FIG. As shown in FIG. 4, the decompression / heating type film forming apparatus 10 includes an aluminum metal film forming chamber 12 that accommodates a wafer W to be formed and holds the wafer W under reduced pressure, and a plurality of heating lamps. And a lamp heating device 14 provided as a heating source for heating the wafer in the film forming chamber 12.

The film forming chamber 12 is connected to a vacuum suction device (not shown), and forms a film on the wafer W by introducing a reaction gas from a reaction gas introduction pipe (not shown) under reduced pressure. . In the chamber wall of the film forming chamber 12 in front of the lamp heating device 14, a circular lamp window 18 into which a heat-permeable quartz glass 16 is fitted is opened in order to transmit heat rays from the lamp heating device 14. . As shown in FIG. 5, the lamp window 18 has a first opening 20 provided on the chamber side of the film forming chamber 12 and a first opening 20.
And a second opening 22 which is concentrically similar to the first opening 20 and is larger than the first opening 20. The second opening wall 24 forming the second opening 22 is formed stepwise with respect to the first opening wall 26 forming the first opening 20, and the second opening wall forming the second opening 22 is formed. Between the wall 24 and the first opening wall 26 forming the first opening 20, there is an intermediate wall 28 orthogonal to both walls, that is, parallel to the quartz glass 16. Quartz glass 1
6 is an O-mount attached to a groove 30 provided in the intermediate wall 28.
The second opening 2 contacts the intermediate wall 28 via the ring 32.
2 are fitted into a chamber wall 24 forming the same.

[0005]

However, the above-described conventional decompression / heating type film forming apparatus has a problem that quartz glass is easily broken during operation. Accordingly, an object of the present invention is to provide a film forming apparatus that prevents quartz glass fitted in a lamp window from breaking.

[0006]

The present inventor has investigated the causes of cracks in quartz glass and found the following. The chamber wall of the film forming chamber 12 and the quartz glass 16 are heated by the lamp heating device 14 and thermally expanded, and are cooled and thermally compressed by turning off the lamp heating device 14.
As this thermal expansion and thermal contraction are repeated, a compressive force acts on the quartz glass 16 due to the difference in the coefficient of thermal expansion. If the quartz glass 16 is not accurately and concentrically attached to the film forming chamber 12, a horizontal force may act on the quartz glass 16. Further, when a film is formed on the wafer, the film forming chamber 12 is in a vacuum state, so that the pressing force is changed from outside the film forming chamber 12 on the atmosphere side to inside the film forming chamber 12 on the vacuum side. It is in a state where it is constantly applied from the outside to the inside of the quartz glass 16.
For this reason, the chamber wall of the film forming chamber 12 and the peripheral end surface of the quartz glass 16 are rubbed in the vertical direction.
Friction acts.

As described above, the compression force acting on the quartz glass 16 due to the difference in thermal expansion and thermal compression between the chamber wall of the film forming chamber 12 and the quartz glass 16 or the quartz glass 16 Further, due to the horizontal force applied to the quartz glass 16 and the frictional force caused by vertical rubbing between the chamber wall and the peripheral end surface of the quartz glass 16,
It has been found that various forces act on the steel to cause cracking.
Also, as shown in FIG.
When it is present on the intermediate wall 28 which is in contact with 6, the force concentrates on the quartz glass 16 via the projections, so that the quartz glass 16 is more easily broken.

Therefore, the present inventor has conceived of absorbing a force that causes cracks in quartz glass by interposing a heat-resistant packing for absorbing force between the chamber wall and the quartz glass. After experimentation, the present invention was invented.

In order to achieve the above object, based on the above findings, a film forming apparatus according to the present invention heats a wafer in a film forming chamber for holding a wafer inside under reduced pressure and a wafer in the film forming chamber. A lamp heating device is provided, and the wafer in the film forming chamber is heated by the lamp heating device through the heat-resistant glass fitted in the lamp window provided by opening the chamber wall of the film forming chamber, and is inserted into the film forming chamber. In a film forming apparatus in which a predetermined film is formed on a wafer by introducing a reaction gas, a packing formed in a ring shape along a peripheral edge of the heat-resistant glass with a heat-resistant plastic having less rigidity than the heat-resistant glass. However, it is characterized in that it is interposed between the chamber wall where the lamp window is opened and the peripheral end of the heat resistant glass. In the present invention, a heat-resistant plastic packing formed in a ring shape along the peripheral edge of the heat-resistant glass and having a smaller rigidity than the heat-resistant glass is formed between the chamber wall with the lamp window opened and the peripheral end of the heat-resistant glass. The interposition therebetween prevents the heat-resistant glass from directly contacting the chamber wall of the metal film-forming chamber, and absorbs the force acting on the heat-resistant glass by the packing. Therefore, there is no friction between the metal of the chamber wall and the heat-resistant glass, and the force acting on the heat-resistant glass is absorbed and the force does not act on the heat-resistant glass, so that the heat-resistant glass does not crack.

In a preferred embodiment of the present invention, the lamp window has a first opening provided inside the chamber and a first opening.
A second opening, which is outside the opening and is concentrically similar to the first opening and is larger than the first opening, and a second opening wall forming the second opening is formed by the second opening wall. The first opening wall forming the first opening is formed in a step shape with respect to the first opening wall, and is continuous with the first opening wall by an intermediate wall parallel to the heat-resistant glass. Is formed with a step relative to the peripheral area so as to protrude toward the chamber side from the peripheral area, and a ring-shaped heat-resistant packing surrounds the central area of the heat-resistant glass and has a thickness greater than the step relative to the peripheral area of the central area. A frame portion formed of a thick member, and a skirt portion extending outward from the outer edge of the frame portion along the peripheral end surface of the heat-resistant glass, has an inverted L-shaped vertical cross section, the heat-resistant glass, Intermediate wall of the second opening via an O-ring in the central region Contact, with the peripheral end face in contact with the second aperture wall through the skirt portion of the heat-resistant packing is fitted in the second opening in the wall.

In a further preferred embodiment of the present invention, the skirt of the heat-resistant packing has a tip having a tapered cross section. Accordingly, the heat-resistant packing is easily deformed in the second opening, so that even when a horizontal force is applied to the heat-resistant glass due to thermal expansion or the like, the force can be absorbed.

In the present invention, the material of the heat resistant glass is not limited as long as it has heat resistance to heating by the lamp heating device, and the material of the heat resistant packing has heat resistance to heating by the lamp heating device. There is no restriction as long as the rigidity is lower than that of the heat-resistant glass. For example, the heat-resistant glass is made of quartz glass, and the ring-shaped heat-resistant packing is made of Teflon (trademark of tetrafluoroethylene polymer of duPont). The shape of the lamp window is arbitrary, but is usually circular.

[0013]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Embodiment Example This embodiment is an example of an embodiment of a film forming apparatus according to the present invention. FIG. 1 is a schematic cross-sectional view showing a configuration of a main part of the embodiment, and FIG. Partial enlarged view and FIG.
FIG. 3 is a cross-sectional view of a part of a ring-shaped packing used in the film forming apparatus of the embodiment. The film forming apparatus of this embodiment is
As shown in FIG. 1, the configuration of the quartz glass 40 is different, and a packing 48 formed in a ring shape along the periphery of the quartz glass 40 is provided between the opening wall of the lamp window 18 and the peripheral end of the quartz glass 40. It has the same configuration as that of the conventional film forming apparatus 10 shown in FIG.

The quartz glass 40 is a disc-shaped quartz glass member. As shown in FIG. 2, a circular central region 42 on the chamber side surface is formed into an annular peripheral region 4 around the central region 42.
The peripheral area 44 is formed with a step so as to protrude toward the chamber side from 4. As shown in FIG. 1, the packing 48 is formed in a ring shape along the periphery of the quartz glass 40, and is made of Teflon having a smaller rigidity than the quartz glass 40. As shown in FIG. It has an inverted L-shaped cross section composed of a frame portion 50 surrounding the region 42 and a skirt portion 52 extending in a direction orthogonal to the outer edge of the frame portion 50, that is, along the peripheral end surface 46 of the quartz glass 40. I have. The frame portion 50 of the packing 48 has the thickness of the frame portion 50 larger than the step of the central region 42 of the quartz glass 40, and the quartz glass 40 is directly laid on the intermediate wall 28 of the film forming chamber 12 even when the O-ring 32 is crushed. It is designed to have a thickness that does not make contact. The skirt portion 52 has a tapered portion 54 at the distal end, the thickness of which is reduced toward the distal end.
Is fitted into the second opening wall 24.

With the above configuration, the quartz glass 40 is
The central region 42 is surrounded by the frame 50 of the packing 48, contacts the intermediate wall 28 via the O-ring 32 in the central region 42, and the intermediate wall 28 via the frame 50 of the packing 48 in the peripheral region 44. Further, the peripheral end surface 46 is in contact with the second opening wall 24 via the skirt portion 52 of the ring-shaped packing 48, and is fitted into the second opening wall 24.

In the present embodiment, a Teflon packing 48 formed in a ring shape along the periphery of the quartz glass 40 and having a smaller rigidity than the quartz glass 40 is attached to the intermediate wall 28 and the second opening wall 24 and the quartz glass 40. The interposition therebetween prevents the quartz glass 40 from directly contacting the chamber wall of the aluminum film formation chamber 12. Therefore, there is no friction between the metal and the glass, so that the quartz glass 40 does not crack. When fitting into the second opening wall 24 of the film forming chamber 12, the packing 48
However, it can be attached concentrically to the second opening 22 as a horizontal guide. Even when a horizontal force is applied to the quartz glass 40, the skirt 5
2 has a tapered portion 54 at the distal end, so that it is easily deformed in the second opening 22 and absorbs a horizontal force so that no force acts on the quartz glass 40. In the actual film forming apparatus having the same configuration as that of the present embodiment, the packing 48 is used.
After mounting, no cracks occurred in the quartz glass.

[0017]

According to the present invention, a packing made of a heat-resistant plastic having a lower rigidity than a heat-resistant glass and formed in a ring shape along the peripheral edge of the heat-resistant glass is used as a heat-resistant material. By interposing the heat-resistant glass and the peripheral wall of the glass, the heat-resistant glass does not come into direct contact with the chamber wall of the metal deposition chamber. Therefore, there is no friction between the metal and the glass, so that the heat-resistant glass does not crack. In addition, since the heat-resistant glass can be concentrically attached to the lamp window provided in the film forming chamber by the guide action of the ring-shaped packing, an abnormal force is not applied to the heat-resistant glass from outside in the horizontal direction. be able to. And these effects can prevent the heat-resistant glass from cracking.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing a configuration of a main part of an embodiment.

FIG. 2 is a partially enlarged view of a quartz glass.

FIG. 3 is a cross-sectional view of a ring-shaped packing used in the film forming apparatus of the embodiment.

FIG. 4 is a schematic cross-sectional view showing a configuration of a conventional film forming apparatus.

FIG. 5 is an enlarged sectional view of a portion A in FIG. 4;

FIG. 6 is a diagram illustrating a problem of a conventional film forming apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Conventional film-forming apparatus 12 Film-forming chamber 14 Lamp heating device 16 Quartz glass 18 Lamp window 20 1st opening 22 2nd opening 24 2nd opening wall 26 1st opening wall 28 Intermediate wall 30 Groove 32 O-ring 40 Quartz glass 42 Circular central area 44 Annular peripheral area 46 Peripheral end face 48 Packing 50 Frame 52 Skirt 54 Tapered

Claims (4)

[Claims] 1. A film forming chamber for holding a wafer inside under reduced pressure, a lamp heating device for heating the wafer in the film forming chamber, and a lamp window provided by opening a chamber wall of the film forming chamber. A film forming apparatus that heats a wafer in a film forming chamber by a lamp heating device through a fitted heat-resistant glass and introduces a reaction gas into the film forming chamber to form a predetermined film on the wafer. In the above, packing formed in a ring shape along the periphery of the heat-resistant glass with heat-resistant plastic less rigid than the heat-resistant glass is interposed between the chamber wall with the lamp window opened and the peripheral end of the heat-resistant glass A film forming apparatus, comprising: 2. A lamp window having a first opening provided inside the chamber and an opening outside the first opening and having a shape concentrically similar to the first opening and larger than the first opening. A second opening wall forming the second opening is formed stepwise with respect to the first opening wall forming the first opening, and is parallel to the heat resistant glass. The intermediate wall is continuous with the first opening wall, and the heat-resistant glass is formed so as to have a step with respect to the peripheral region so that the central region of the chamber-side surface protrudes toward the chamber side from the peripheral region. The packing surrounds the central region of the heat-resistant glass, and a frame formed of a member having a greater thickness than a step with respect to the peripheral region of the central region, and outward from the outer edge of the frame along the peripheral end surface of the heat-resistant glass. It is composed of an elongated skirt and an inverted L-shaped The heat-resistant glass has a longitudinal section, and the heat-resistant glass contacts the intermediate wall of the second opening via the O-ring in the central region, and contacts the second opening wall via the skirt portion of the heat-resistant packing at the peripheral end surface. The film forming apparatus according to claim 1, wherein the film forming apparatus is fitted into the two opening walls. 3. The film forming apparatus according to claim 2, wherein the skirt portion of the heat-resistant packing has a tip portion having a tapered cross section. 4. The heat-resistant glass is formed of quartz glass,
Ring-shaped heat-resistant packing is made of Teflon (duPont
The film forming apparatus according to any one of claims 1 to 3, wherein the film forming apparatus is made of (Pont) a trademark of a tetrafluoroethylene polymer).