JPH07230956A - Plasma cvd device - Google Patents

Abstract

PURPOSE:To keep the inner wall of a plasma generating chamber uniform in temperature, to improve the film quality in a CVD process, and to remarkably prolong a device in continuous operating time. CONSTITUTION:An inner chamber 56 is provided inside a processing chamber 9, and a plasma generating chamber 26 is provided inside the inner chamber 56, so that a plasma CVD device is of double structure. An empty space is provided between the inner wall of the processing chamber 9 and the outer wall of the inner chamber 56 where a heat insulating plate 12 is provided, and the inside of the plasma generating chamber 26 is covered with an insulator of quartz or the like composed of a side wall cover 23, an upper electrode cover 22, and a lower electrode cover 24.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma CVD apparatus used for forming various thin films on a substrate in the process of manufacturing semiconductor devices and the like, and particularly to film formation by uniformly heating a plasma generating chamber. The present invention relates to a parallel chamber plasma CVD apparatus with a double chamber structure, which suppresses the adhesion of powder generated in the plasma to the plasma generation chamber, thereby preventing the incorporation of defect factors into the film and extending the continuous operation time. .

[0002]

2. Description of the Related Art A semiconductor manufacturing process includes forming a desired film on a surface of a silicon substrate, or one of manufacturing processes of a liquid crystal display device includes forming a film on a glass substrate. This is because a substrate is loaded in an airtight processing chamber, high-frequency power is applied between a pair of electrodes provided in the processing chamber, and a reaction gas is supplied into the processing chamber to generate plasma, thereby generating a plasma on the substrate surface. A thin film is formed on. Conventional plasma CV
In the apparatus D, there is one electrode on which the substrate is installed on one surface in the airtight processing chamber, and the other electrode is provided on the other surface in the airtight processing chamber facing the electrode, and the electrode on which the substrate is installed. Was heated by a heater to keep the substrate at a predetermined temperature, and plasma was generated between the pair of electrodes to perform the CVD process.

The CVD process decomposes gas phase gas molecules and deposits them as a thin film on a substrate. However, the thin film is formed not only on the substrate but also on the electrode facing the substrate and the inner wall of the processing chamber. The film deposited on the electrodes and the inner wall of the processing chamber eventually peels off to form flakes, which adhere to the substrate being processed and contaminate the substrate. When the substrate is contaminated with the deposit, it causes serious defects in the film formation of the substrate. Therefore, conventionally, the processing chamber has been regularly cleaned.

However, the cleaning work must be performed by disassembling the processing chamber, and the work is complicated and time-consuming. Therefore, this cleaning work has been a cause of lowering the operating rate of the apparatus. Further, it is known that uniform plasma can be obtained by generating plasma in a limited space, and it is required that the space for generating plasma is limited to a necessary minimum. In order to address such a problem, in order to store the substrate and generate plasma in a limited space, a plasma generation chamber is further provided in the processing chamber to form a double chamber, and the plasma generation chamber can be cleaned to facilitate cleaning work. A plasma CVD apparatus has been proposed which is designed to achieve high efficiency.

Further, in the conventional parallel plate type plasma CVD apparatus, since one electrode of the pair of electrodes on which the substrate is installed is heated by the heater, the temperature of the other electrode facing the electrode and the temperature of the inner wall of the processing chamber. Is lower than the substrate. Of these parts, the part with relatively high temperature,
As described above, the problem due to these deposits, in which a film having a weaker sticking force than that of the substrate is formed, and powdery reaction products called powder adhere to the low temperature portion. To solve such a problem, a pair of electrodes are heated by both heaters to form a hot wall structure, a CVD product is strongly formed on the electrode surface, and dust particles generated by peeling are suppressed. A plasma CVD apparatus has been devised so as to extend the continuous operation time. Plasma CV with a hot-wall double chamber structure incorporating this idea
An example of the D device is shown in FIG.

[0006]

In the conventional apparatus shown in FIG. 2, the plasma generating chamber 26 is provided in the processing chamber 9, and the upper electrode plate 21 and the lower electrode plate 28 are connected to the upper electrode heater 19 and the lower electrode. Even if heating is performed by the heater 29, the water cooling flange 52 passes from the frame body 43 through the processing chamber lid 1.
Since the heat that reaches the side is large, the ambient temperature of the side wall cover 23 and the upper electrode cover 22 becomes low, and the film formed on the side cover 23 peels off or the adhered powder detaches. Was.

In the plasma CVD apparatus having a single-chamber structure, the side wall of the processing chamber 9, which is a low temperature portion where flakes are easily generated and powder is attached and detached, is located relatively far from the substrate 27. Even if flakes and powder are peeled off or separated, it is considered that the influence on the substrate is small. However, in the plasma CVD apparatus having the double chamber structure, from the viewpoint of cost performance including the installation area of the apparatus,
There is a limit to the expansion of the processing chamber 9 due to the double-chamber structure, and the distance between the side wall of the plasma generation chamber 26 and the substrate 27 has to be made smaller than that of a plasma CVD apparatus having a single-chamber structure. That is, it can be said that in the plasma CVD apparatus having the double structure, the generation of flakes on the side wall and the attachment / detachment of powder are more problematic than the single chamber structure apparatus in terms of substrate contamination.

[0008]

SUMMARY OF THE INVENTION In view of the above situation, the present invention prevents the temperature of the side wall of the plasma generation chamber in a plasma CVD apparatus having a double chamber structure from decreasing and makes the temperature of the inner wall of the plasma generation chamber uniform. Thus, it is intended to provide a plasma CVD apparatus capable of significantly suppressing flake generation and powder adhesion on the electrode surface and sidewalls.

That is, according to the apparatus of the present invention, the plasma generation chamber 26 is provided in the processing chamber 9 to form a double chamber structure.
In the apparatus, a space is provided between the inner wall of the processing chamber 9 and the outer wall of the inner chamber provided with the heat insulating plate 12, and the inside of the plasma generation chamber 26 is covered with an insulating material so that the temperature of the plasma generation chamber 26 can be kept uniform. It is a feature.

[0010]

[Operation] With such a configuration, the reaction gas is supplied to the plasma generation chamber 26 from the gas inlet 11 and
When high-frequency power is applied between the pair of electrode plates 21 and 28 to generate plasma, the temperature of the plasma generation chamber 26 can be kept uniform, and the substrate 27 mounted on the lower electrode plate 28 is of good quality. A film will be formed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG. A processing chamber cover 1 is provided on the upper surface of the processing chamber 9, and a heat insulating plate 12 is installed on the processing chamber cover 1. A plurality of support pins 18 are arranged in the gap formed between the heat insulating plate 12 and the processing chamber lid 1. By pressing the heat insulating plate 12 against the support pins 18, the heat insulating plate 12 is placed at a predetermined position. Fixed to. The gas introducing pipe 10 penetrating the upper surface of the processing chamber lid 1 is provided at the center of the heat insulating plate 12, and the upper electrode heater 19 and the upper electrode plate 21 are provided at the lower end of the gas introducing pipe 10, and the gas introducing pipe 1 is provided.
0, the upper electrode heater 19, and the upper electrode plate 21 are insulated by an insulating plate 14, an insulating plate 15, and an insulating ring 13 made of an insulating material such as quartz.

A gas dispersion plate 20 is inserted between the upper electrode heater 19 and the upper electrode plate 21, and the gap formed by these is communicated with the inside of the gas introduction pipe 10. Further, the gas distribution plate 20 is provided with a required number of distribution plate gas supply holes 54. The gas introduction pipe 10 communicates with a gas introduction port 11 provided through a gas introduction flange 3. A water cooling flange 2 having a structure that allows cooling water to flow is installed between the gas introduction flange 3 and the processing chamber lid 1, and a water cooling flange 4 is installed above the gas introduction flange 3 to protect the O-ring seal portion. Cooling is performed to prevent deterioration of the sealing material due to high temperatures.

The inner chamber 56 defining the plasma generation chamber 26 below the heat insulating plate 12 is in airtight contact with the lower surface of the heat insulating plate 12 and constitutes a side wall, and the air chamber is in contact with the frame member 43.
The lower electrode plate 28 that faces the upper electrode plate 21 and a lower electrode heater 29 that adheres to the lower surface of the lower electrode plate 28 are mainly configured.
The frame body 43 and the lower electrode plate 2 are used while being connected.
8 and the lower electrode heater 29 are separable vertically.

A side wall cover 23 made of an insulating material such as quartz is provided inside the frame body 43, and an upper electrode cover 22 made of an insulating material such as quartz is detachably provided on the upper end surface of the side wall cover 23. A large number of reaction gas dispersion holes 51 are formed in the upper electrode cover 22, and a slight gap is provided between the upper electrode cover 22 and the upper electrode plate 21 to form a gas reservoir 5.
Form 7. The central portion of the lower electrode plate 28 is the substrate 2
7, the exhaust duct groove 25 is engraved around the substrate 27 mounting portion, the exhaust plate 59 is disposed in the exhaust duct groove 25, and the exhaust plate 59 is provided on the upper surface of the exhaust plate 59. An exhaust cover 58 made of quartz is placed.

Further, the lower electrode cover 24 made of an insulating material such as quartz is mounted on the upper surface of the exhaust cover 58. Further, the exhaust plate 59 communicates with the plasma generation chamber 26 via the exhaust lid 58 and the lower electrode cover 24, and also communicates with the inside of the processing chamber 9. The inner surface of the plasma generating chamber 26 is entirely made of an insulating material such as quartz, and the side wall cover 23 and the upper electrode cover 2 are provided.
2. It will be covered with the lower electrode cover 24.

A pressing plate 3 is provided below the lower electrode heater 29.
2 is provided, and the lower electrode heater 29 is provided on the pressing plate 32 via the support column 35, and the positioning is performed by the guide pin 3
It is done by 0. A heat reflection plate 31 is provided below the lower electrode heater 29, and a pressing plate 32 is provided by a reflection plate stopper 41.
Is fixed to the lower electrode heater 29 and is heat-insulated with respect to the lower side of the lower electrode heater 29. An elevating guide shaft 34 is connected to the pressing plate 32, and the guide shaft 34 penetrates the bottom of the processing chamber 9 in an airtight manner and is connected to an elevating unit (not shown).

Further, at least three substrate support pins 33 penetrating the lower electrode plate 28 and the lower electrode heater 29 are provided. The substrate support pins 33 penetrate the bottom of the processing chamber 9 in an airtight manner and are shown in the drawing. Not connected to the lifting unit. From the upper electrode heater 19, the upper electrode heater sheath wire 37 and the upper electrode thermocouple 38 airtightly penetrate the upper surface of the gas introducing pipe 10 and the sleeve fixing flange 8 installed in the gas introducing pipe 10 for heating the upper electrode. It is possible to supply electric power and measure the temperature of the upper electrode heater 19.

Further, from the lower electrode heater 29, a lower electrode heater sheath wire 39 and a lower electrode thermocouple 40 communicate with the inside of the guide shaft 34, and penetrate the guide shaft 34 in an airtight manner to generate a lower electrode heating power. And the temperature of the lower electrode heater 29 can be measured.

The operation of this embodiment having the above configuration will be described. The inside of the processing chamber 9 is exhausted by an exhaust system (not shown).
Evacuate from 4 to vacuum. Upper electrode heater sheath wire 37
Power is supplied from an upper electrode heater power supply (not shown) to the lower electrode heater sheath wire 39 (not shown), and the lower electrode cover 24, the substrate 27 side wall cover 23 and the upper electrode cover are supplied. The temperatures of the upper electrode heater 19 and the lower electrode heater 29 are kept constant so that 22 has a uniform temperature distribution.

When the substrate 27 is carried in, the lower electrode plate 28 is lowered via the guide shaft 34 and the lower electrode heater 29. At this time, the substrate support pin 33 also descends. Open a gate valve (not shown) to open the substrate transfer port 42.
And the robot arm (not shown) on which the substrate 27 is placed is inserted into the processing chamber 9, and the lower electrode plate 28
The substrate 27 is held above.

The substrate support pin 33 is raised so as to project upward from the lower electrode plate 28. The protrusion of the substrate support pin 33 supports the substrate 27 by the substrate support pin 33. A robot arm (not shown) is retracted, the substrate transfer port 42 is closed by a gate valve (not shown), and the substrate support pin 33 is lowered to place the substrate 27 on the lower electrode plate 28. The guide shaft 34 is raised, and the lower electrode plate 28 is pressed against the frame body 43 via the lower electrode heater 29.

The reaction gas supplied from the gas introduction port 11 passes through the gas introduction pipe 10 and the gas dispersion plate 20, the reaction gas dispersion hole 55 of the upper electrode plate 21 and the reaction gas dispersion hole of the upper electrode cover 22. It is uniformly dispersed at 51 and introduced into the plasma generation chamber 26. The reaction gas introduced into the plasma generation chamber 26 flows into the processing chamber 9 through the exhaust duct groove 25, and is further exhausted from the exhaust port.

High-frequency power is applied between the upper electrode plate 21 and the lower electrode plate 28 while the reaction gas is introduced and exhausted, plasma is generated in the plasma generation chamber 26, and a gas phase is formed on the surface of the substrate 27. Deposition (CVD process) is performed. When the CVD process of the substrate 27 is completed, the carrying-in operation of the substrate 27 is reversed to carry out the carrying-out operation of the substrate 27.

In performing the CVD process on the substrate 27, the heat insulating plate 12 is provided in the inner chamber 56, and the support pin 18 is provided between the process chamber lid 1 of the process chamber 9 and the heat insulating plate 12 provided in the inner chamber 56. This creates a space. Therefore, the conduction of heat to the inner chamber 56 is suppressed to be extremely small,
The influence of the water cooling flange 2 and the like is extremely small, and the plasma generation chamber 26 maintains a uniform temperature distribution. Further, since the plasma generation chamber 26 is entirely covered with an insulator such as quartz, local concentration of plasma on the exposed metal portion is prevented, which contributes to plasma stability and uniform temperature distribution. .

[0025]

As described above, according to the present invention, the temperature of the inner wall of the plasma generation chamber is kept uniform, and the plasma generation chamber is completely made into a hot wall, so that powder adhesion to the inner wall is suppressed. Moreover, it is possible to firmly form the film on the inner wall and avoid the peeling of the film to suppress the generation of flakes, thereby preventing substrate contamination during the CVD process, improving the film quality, and continuously operating the apparatus. Can be significantly extended.

[Brief description of drawings]

FIG. 1 is a sectional view showing the configuration of an embodiment of the device of the present invention.

FIG. 2 is a sectional view showing a configuration of an example of a conventional device.

[Explanation of symbols]

 1 Processing Chamber Lid 9 Processing Chamber 12 Insulating Plate 13 Insulating Ring 14 Insulating Plate 15 Insulating Plate 18 Support Pin 19 Upper Electrode Heater 21 Upper Electrode Plate 22 Upper Electrode Cover 23 Sidewall Cover 24 Lower Electrode Cover 26 Plasma Generation Chamber 27 Substrate 28 Lower Electrode Plate 56 Interior

Claims (1)

[Claims] 1. In a plasma CVD apparatus having a double structure in which an inner chamber is provided in the processing chamber and a plasma generating chamber is provided in the inner chamber, a space is provided between the inside of the processing chamber and the inner chamber provided with a heat insulating plate. A plasma CVD apparatus, which is provided and covers the inside of the plasma generation chamber with an insulator.