JPH09213689A - Plasma processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To move a plurality of materials to be treated leaving as the temperature of the materials to be treated is held constant to make a multilayer film form by a method wherein a placement board, which is a second electrode, is rotatable in opposition to the gas disperser of a first electrode and is placed with the plurality of the materials to be treated along the direction of rotation, is provided. SOLUTION: A conductive plate 101 consisting of a tantalum film or a tungsten film is extended on the surface of a placement board 35. A second electrode 102, which comes into contact with this plate 101, is used for ionizing reaction gas and consists of a tantalum film or a tungsten film, is buried in the board 35. The electrode 102 has a function given as the other electrode of opposed electrodes. Moreover, heaters 103 are buried in the lower part of the board 35 under this electrode 102 via an insulator 104. The insulator 104 consists of an insulating material having a thermal expansion coefficient roughly equal with that of the material for the plate 101, the electrode 102 and the heaters 103.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus, and more particularly to a plasma processing apparatus for performing film formation or etching with plasma gas.

[0002]

2. Description of the Related Art Conventionally, a multi-chamber CVD apparatus, a walking beam type continuous CVD apparatus, and a multi-reactor batch type CVD apparatus have been mainly used for film formation by a CVD method on a mass production scale.

As shown in FIG. 10, the multi-chamber CVD apparatus is provided with each processing chamber 3a to 3f independently, so that various different processings can be performed and the flexibility is high. Further, it is possible to provide a plasma generator in each of the processing chambers 3a to 3f to form a plasma CVD apparatus. In FIG. 10, 1 is a load lock chamber, 2 is a robot installed in the load lock chamber 1, and 4 is wafers 6a to 6 in the processing chambers 3a to 3f.
It is a robot that carries in or out f.

As shown in FIG. 11, the walking beam continuous CVD apparatus includes a wafer mounting table 12 in which a plurality of wafer mounting portions 13a to 13h are arranged in a single processing chamber 11, and wafers 15a to 15h. Beams 14a to 14h capable of holding around and rotating about an axis of rotation
And is installed. In addition, each of the wafer mounting portions 13a to 1
A heater is provided at 3h. In FIG. 11, 7 is the first
Load lock chamber, 8 is a robot installed in the first load lock chamber 7, 10 is a second load lock chamber, 9a is a valve that opens and closes between the chamber 7 and the second load lock chamber, and 9b. Is a valve that opens and closes between the second load lock chamber 10 and the processing chamber 11.

By using the walking beams 14a to 14h to sequentially rotate and move the wafers 15a to 15h, film formation is continuously performed and high throughput is obtained. By dividing the film formation and stacking the films formed by the respective reactors, it is possible to eliminate the difference between the wafers 15a to 15h. Multi-reactor batch system C
As shown in FIG. 12, the VD apparatus is provided with a plurality of wafer mounting portions 22a to 22d individually serving as electrodes for converting reaction gas into plasma on a wafer mounting table 21 in a single processing chamber. There is. The wafer mounting table 21 is rotated by a rotating shaft 25 in a fixed direction for each film formation. Further, the shower head-equipped electrodes 23a to 23d for individually supplying the reaction gas and the high-frequency power to the wafer mounting portions 22a to 22d are provided in the wafer mounting portions 22a to 22d.
It is provided opposite to 22d.

In the multi-reactor type batch type CVD apparatus, the wafers 26a to 26d are transferred to the plurality of wafer mounting portions 22a to 22d, respectively, and then the film forming process is collectively performed. The wafers mounted on the wafer mounting portions 22a to 22d are lifted for each film formation by a robot (not shown) and sequentially moved on the wafer mounting portions 22a to 22d. Further, the shower head-equipped electrode 23a for individually supplying the reaction gas and the high frequency power to each of the wafer mounting portions 22a to 22d.
23d are provided for each of the wafer mounting portions 22a to 22d so as to face the wafer mounting portions 22a to 22d.

In the multi-reactor type batch type CVD apparatus, the wafers 26a to 26d are transferred to the plurality of wafer mounting portions 22a to 22d, respectively, and then the film forming process is collectively performed. Further, different kinds of reaction gases are supplied to the shower heads 23a to 23d, and the wafer 26 is formed for each film formation.
a to 26d are lifted to move to the next wafer mounting portions 22a to 22d.
By moving to d, it is possible to continuously form different types of multilayer films. Furthermore, it is possible to obtain a throughput that is proportional to the number of wafers 26a to 26d that are collectively processed.

Among the above three types of CVD apparatuses, the multi-reactor batch type CVD apparatus can obtain the highest throughput.

[0009]

However, in the multi-chamber CVD apparatus, the robot 4 has one processing chamber 3
The wafers 6a to 6f are unloaded from the wafer a, and the next processing chamber 3
Since it is necessary to carry out the operation of loading into b, it takes a long time to carry it, and it is not possible to obtain a throughput proportional to the number of the processing chambers 3a to 3f. Also,
An exhaust system and a gas supply system are required for each of the processing chambers 3a to 3f. Further, since the reaction gas and the high frequency power supply system are different between the reactors, there is an inherent difference in the supply amount of the reaction gas and the high frequency power between the reactors, and the film thickness of the film formed between the wafers 6a to 6f. And the film quality will be different.

In the plasma CVD apparatus, a high frequency power source for excitation has to be installed, and there is a problem that the apparatus becomes large. Since the walking beam type continuous CVD apparatus cannot separate the reaction gas and the high frequency power between the reactors due to the single processing chamber 11, therefore, different kinds of multilayer films are continuously formed. It is not possible. Further, when the wafers 15a to 15h are moved to move to the next film formation after forming one film, the wafer wafer 15
Since a to 15h are separated from the mounting table, wafers 15a to 15a
It is unavoidable that the temperature drops for 5 hours. This causes a temperature cycle during film formation,
There is a problem that strain remains in the formed film. Also, wafer 1
It is necessary to interrupt the film formation during the movement of 5a to 15h, reheat the wafers 15a to 15h to a predetermined temperature after the movement, and wait for stabilization of the gas flow rate. For this reason, the processing time becomes long, and as a result, there arises a problem that high throughput cannot be obtained.

Furthermore, multi-reactor type batch type CVD
In the apparatus, the wafers 26a to 26d are mounted on the wafer mounting portion 22a.
Since they can be moved one after another up to 22d, they have the same problems as the walking beam type CVD apparatus, and since the reaction gas and high frequency power supply systems are different between each reactor, the reaction gas and high frequency power are different between each reactor. There is an inherent difference in the supply amount of the wafers 26a to 26d in the same batch.
There may be a difference in film thickness and film quality between the formed films.

The above-mentioned problems also occur in an etching apparatus having a similar structure using plasma gas, and its solution is desired. The present invention has been made in view of the above conventional problems, and a plurality of objects to be processed are moved while keeping the temperature of the objects to be processed constant, and a film having a uniform film thickness, film quality, or the like is different. An object of the present invention is to provide a plasma processing apparatus capable of forming various kinds of multilayer films or performing uniform etching, obtaining high throughput, and preventing the apparatus from increasing in size.

[0013]

The above object is a first invention, which is a first electrode, which is a gas disperser for releasing a reaction gas, and a second electrode, which is the gas disperser. A high-frequency power supply, which is capable of rotating in opposition to and a plasma processing apparatus having a mounting table on which a plurality of objects to be processed are mounted along the rotation direction, and which is the second invention, and which converts the reaction gas into plasma. Is achieved by the plasma processing apparatus according to the first aspect of the present invention, and is a third aspect of the present invention, in which the bias is applied to the object to be processed placed on the mounting table. An AC power supply for applying a voltage is connected to the second electrode, which is achieved by the plasma processing apparatus according to the first or second aspect of the invention.
In the invention, the gas disperser is connected to a gas inlet for introducing the reaction gas, a gas passage for guiding the reaction gas from the gas inlet, and the gas passage, on the mounting table. It is achieved by the plasma processing apparatus according to any one of the first to third inventions, characterized in that it has a gas discharge portion formed in an annular shape at a position facing the object to be processed,
According to a fifth aspect of the present invention, the gas disperser includes a plurality of gas inlets capable of independently introducing different reaction gases, and a plurality of gas inlets each independently introducing the reaction gas from the plurality of gas inlets. A gas flow path, and a plurality of gas discharge parts that are independently connected to each of the plurality of gas flow paths and that are annularly arranged at a position facing the object to be processed that is annularly arranged on the mounting table. According to another aspect of the present invention, there is provided a plasma processing apparatus according to any one of the first to third aspects of the invention.
A plurality of gas emission holes are distributed in the gas emission part, which is an invention of the present invention, which is achieved by the plasma processing apparatus according to the fourth or fifth invention, which is a seventh invention. The plasma processing apparatus according to any one of the first to sixth inventions, wherein the mounting table includes a single heater installed on the mounting table below the mounting portion of the object to be processed. The eighth aspect of the present invention is the eighth aspect of the present invention, wherein the mounting table includes a plurality of heaters individually installed on the mounting table below the mounting portions of the plurality of objects to be processed. According to a ninth aspect of the present invention, the second electrode and the heater are formed on a common base made of an insulating material. Alternatively, according to the plasma processing apparatus of the eighth invention, According to a tenth aspect of the present invention, the gas disperser includes a conductive gas pipe having a coil-shaped portion that connects the gas discharge hole or the gas discharge group and the gas introduction port, The invention is achieved by the plasma processing apparatus according to any one of the first to ninth inventions, characterized in that a power supply for supplying high-frequency power is connected to the gas pipe downstream of the portion of the shape. The gas disperser and the mounting table are installed in a decompressible processing chamber, and a rotating shaft is attached to the mounting table so that the rotating shaft can be pulled out of the processing chamber to rotate. It is achieved by the plasma processing apparatus according to any one of the first to tenth aspects of the invention.

In the plasma processing apparatus of the present invention, since the mounting table holding a plurality of objects to be processed is rotatably moved with respect to the gas disperser, the reaction gas from the gas disperser is removed. If the supply is biased by location,
Alternatively, even if the flow of the reaction gas is biased due to the asymmetry in the apparatus configuration, the supply of the reaction gas to the object to be processed is equalized by rotating the mounting table in one direction or in both left and right directions during film formation. . As a result, a film having a uniform film thickness and film quality can be formed on the plurality of objects to be processed.

Further, by forming the counter electrodes (first and second electrodes), which also serve as the gas disperser and the mounting table, respectively into a single electrode, only one high frequency power supply is required. Furthermore,
By using a single heater for the mounting table, only one power supply is needed to supply power to it. As a result, the size of the device can be prevented from increasing. By the way, when the object to be processed is arranged along the circumference of the mounting table and a single gas disperser is used, when the reaction gas is supplied onto the processing object from the central part of the mounting table, Since the reaction gas is supplied from a position off the center of the body, the amount of gas supplied to the surface of the object to be processed is increased in the radial direction of the mounting table while the reaction gas spreads from the center to the periphery of the mounting table. Deviation may occur. In another plasma device of the present invention, a single gas disperser having a gas introduction port in the central portion is used, and a gas discharge portion is formed in an annular shape facing a plurality of objects to be processed. It has a narrow gas flow path connecting the gas inlet and the gas inlet.

Therefore, since the reaction gas is sent from the gas inlet to the gas outlet through a narrow gas passage, the reaction gas introduced from the gas inlet is sent to the gas outlet without spreading more than necessary. Therefore, the supply of the reaction gas to the gas releasing portion is made uniform. Further, since the reaction gas is supplied from the gas releasing portions to almost directly above the object to be processed, the supply amount of the reaction gas to the object to be processed can be made more uniform.

Further, since the mounting table is provided with the heater, it is possible to rotate the mounting table while heating the object to be processed. Thereby, the object to be processed can be moved while the temperature of the object to be processed is kept at a predetermined temperature. Further, since the heaters are individually provided to the plurality of mounting portions of the mounting table, when the thermal conductivity and the heat generation amount of the heaters in the respective mounting portions of the object to be processed differ, the heat generation of each heater By adjusting the amount, it is possible to make the temperature of the object to be processed of each mounting part uniform.

Further, by switching the reaction gas after forming one film, a film of a type different from the movement of the object to be processed is continuously formed while keeping the temperature of the object to be processed at a predetermined temperature. be able to. Thereby, high throughput can be obtained. Further, if the temperature of the object to be processed is set to a predetermined temperature and the gas flow rate and the like are set, it is not necessary to readjust the temperature of the object to be processed and the gas flow rate until the film formation is completed. The accuracy of the film forming conditions can be improved without being affected by the change in the film forming conditions.

Further, since a plurality of gas discharge portions respectively connected to a plurality of independent gas inlets are provided, even if the length, inner diameter, etc. of the gas passages of the gas disperser after fabrication are different depending on the location, each gas By adjusting the flow rate of the reaction gas introduced from the introduction port, it becomes possible to make the amount of the reaction gas released from each gas release part uniform. Thereby, it is possible to form a multi-layered film having a uniform film thickness and different film quality on the wafer.

Further, the gas disperser and the gas inlet are connected to each other, and a conductive gas pipe having a coil-shaped portion is provided. Since the gas pipe formed in a coil shape has a function as a coil that blocks the conduction of high frequencies, when the high frequency power is supplied from the high frequency power source connected downstream of the coiled portion, the gas inlet and the high frequency power source are supplied. It is possible to prevent the high-frequency power from escaping to the gas introduction port side even if an insulator is not present in a part of the gas pipe between the connection part and.

Further, since the rotary shaft attached to the mounting table is rotatably supported outside the processing chamber, it is possible to prevent dust generation in the apparatus due to abrasion of the support portion due to rotation. it can.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 is a side view showing a plasma CVD apparatus according to a first embodiment of the present invention.

In FIG. 1, 31 is a single processing chamber, 32 is a loading / unloading port for loading or unloading a wafer (object to be processed) into the processing chamber 31, and a valve 56 for opening / closing the loading / unloading port. Is provided. An exhaust port 33 is connected to an exhaust device (not shown). Processing chamber 3
The inside of 1 is exhausted through an exhaust port 32 and can be depressurized to a predetermined pressure.

Further, in the processing chamber 31, there are provided a rotary holder 34 to which a wafer mounting table 35 is attached, and a gas disperser 47 facing the wafer mounting surface of the mounting table 35. The gas disperser 47 includes a gas inlet for introducing a reaction gas and a gas discharge hole for discharging the reaction gas, which are connected to each other by a gas flow path. Further, a gas pipe is connected to the gas inlet of the gas disperser 47, and the gas inlet 49 of the gas pipe is connected to the gas inlet of the gas disperser 47 through the gas flow passage 48 formed by the gas pipe. There is. Part of the gas pipe is an insulator 50
It has conductivity except that it is made of.

The gas disperser 47 has a function as one electrode (first electrode) of the counter electrodes for converting the reaction gas into plasma, and is made of a conductor. A high-frequency power source 54 for converting the reaction gas into plasma is connected to the conductive gas pipe connected to the gas disperser 47 via the matching circuit 53. 13.56 MHz is used as the frequency of the high frequency power supply 54. As the frequency of the high frequency power supply 54, 100 kHz or another frequency may be used in some cases. In addition, the gas inlet 49
The conductive gas pipe on the side is grounded. The reason why the gas pipe is installed is to prevent a person who touches a gas cylinder connected to the gas pipe from receiving an electric shock. The reason why a part of the gas pipe is made of the insulator 50 is that when a conductor is used for the entire gas pipe, the high frequency power is not supplied to the gas disperser 47 as an electrode and the gas in the gas pipe is not supplied. Inlet 4
The reason is that it is possible to escape to the 9th direction.

The rotary holder 34 includes a mounting table 35 and a side wall 34.
a, the lower wall 34b, and the rotating shaft 40,
The rotary shaft 40 rotates in one direction or in both left and right directions. A heater 51 is attached to the surface of the gas disperser 47 opposite to the gas discharge surface. This is produced by the reaction gas emitted from the gas disperser 47,
Moreover, since the reaction product attached to the gas disperser 47 is soft as it is and easily peels off into particles, the reaction product is hardened by heating the gas disperser 47 to about 200 ° C. to make it difficult to peel off. is there.

Details of the mounting table 35 are shown in FIGS. 2 (a) and 2 (b). 2A is a top view, and FIG. 2B is a plan view of FIG.
FIG. 2 is a sectional view taken along line II-II. According to the figure, a conductive plate 101 made of tantalum or tungsten is stretched on the surface of the mounting table 35, and a second electrode made of tantalum or tungsten for contacting the conductive plate 101 to turn the reaction gas into plasma. 102 is embedded. The second electrode 102 has a function as another electrode of the counter electrode. Further, the insulator 10 is provided below the mounting table 35 below the second electrode 102.
Heater 10 made of tantalum or tungsten via 4
3 is embedded. The insulator 104 is the conductive plate 10.
The first and second electrodes 102 and the heater 103 are made of an insulating material having a thermal expansion coefficient substantially equal to that of tantalum or tungsten, for example, alumina ceramics.

A wiring 41 is connected to the first electrode 102, and the other end of the wiring 41 is connected to a high frequency power source (not shown). During plasma generation, high-frequency power having a frequency of 380 kHz, for example, is supplied to the first electrode 102 so that the wafers 55a to
Bias 55d to a negative voltage. Other wires 42a and 42b are connected to the heater 103, and the other ends of the wires 42a and 42b are connected to a DC power supply (not shown). DC power is supplied to the heater 103 to generate heat, and the wafers 55a to 55d are heated.

The film deposition rate can be increased by biasing the wafers 55a to 55d to a negative voltage.
The denseness of the formed film can be increased by biasing the wafers 55a to 55d to a negative voltage and heating them. The mounting table 35 described above is created as follows. That is, the heater 103 is placed on the first green sheet of alumina, and the heater 103 is covered with the second green sheet of alumina,
Further, the second electrode 102 is placed on it. And the second
After covering the electrode 102 with a third green sheet made of alumina, the third green sheet on the second electrode 102 is removed to expose the second electrode 102. Then, the conductive plate 101 is placed on the second electrode 102 and the third green sheet around the second electrode 102 and then heated to cure the green sheet. As a result, the mounting table 35 in which the second electrode 102 and the heater 103 are integrally embedded is created. Since the second electrode 102 and the heater 103 are integrally embedded in the ceramic, the strength against the thermal stress due to the difference in the thermal expansion coefficient is increased.
It is possible to prevent the ceramic from cracking due to the heating.

When the wirings 41, 42a and 42b are directly connected to the above high frequency power source and DC power source, the mounting table 35 is used.
Although the wirings 41, 42a, 42b are twisted by the rotation of No. 4, the wirings 41, 42a, 42b can be prevented from being twisted by repeating the rotation of the mounting table 35 by the same number of rotations. Further, the high frequency power source and the DC power source and the wirings 41 and 42
If the contacts (a rotary connector) attached to both the power source side and the rotating shaft 40 side are used for connection with a and 42b, twisting of the wirings 41, 42a, and 42b can be prevented even in one-direction rotation.

Further, as shown in FIG. 1, a wafer lifter 38 for attaching and detaching the wafer 55c to and from the mounting table 35 is provided below the mounting table 35. Wafer lifter 38
By pushing up, the wafer lift pins 39 inserted into the through holes formed in the mounting table 35 separate the wafer 55c from the mounting table 35. Further, since the temperature of the mounting table 35 is raised by heating, the iron powder grease 43b of the fluid magnetic shield 43 provided below the mounting table 35 is heated to keep the gap between the rotary shaft 40 and the apparatus airtight, for example. There is a risk of deterioration due to. In order to avoid this, it is necessary to suppress heat transfer to the lower side of the device as much as possible. Therefore, the mounting table 35 prevents the heat conduction and suppresses the heat radiation.
It is supported at several places by a thin stainless steel support rod 37 and is kept away from the lower part of the device as much as possible.
The fluid magnetic shield 43 is composed of a magnet 43a and iron powder grease 43b. For example, as shown in the drawing, in order to seal the gap between the rotary shaft 40 and the base 58 of the apparatus, the iron powder grease is placed in the gap. 43b is packed and the base 58 side is formed by the magnet 43a so that the iron powder grease 43b does not move and the airtightness inside the processing chamber 31 is maintained.

Further, the wiring 4 is provided at the center of the lower wall 34b.
Through holes for drawing out 1, 42a, 42b are formed. Further, a rotating shaft 40 having a diameter larger than that of the through hole is attached to the lower wall 34b around the through hole, and the wirings 41, 42a, 42b pass from the mounting table 35 through the through hole, and further rotate. It is pulled out through the inside of 40.

Further, the rotary holder 34 is held by a ball bearing 45 at a predetermined distance from a base 58 of the apparatus. A plurality of concentric partition screens 44 are formed on the lower surface of the lower wall 34b of the rotary holder 34 and the upper surface of the base 58, and the rotary holders 34 are rotated by interlocking them in a comb shape. The gap between the shielding plates 44 is narrow, and the cross-sectional shape of the gap is bent in multiple layers to form a zigzag shape. For this reason, the conductance of the gap is small, and the reaction gas that has become unnecessary after being supplied to the wafers 55a to 55d is unlikely to flow through this gap. Further, the passage of particles generated by the reaction of the reaction gas is also suppressed. As a result, the lower wall 34b of the rotary holder 34 and the base 5 of the apparatus are provided downstream of the shield plate 44.
It is possible to prevent the reaction product from adhering to the ball bearing 45 sandwiched between 8 and to prevent the iron powder grease 43b and the like from being contaminated by particles. Further, even a small amount of the reaction gas that has passed through these is exhausted from the exhaust port 33 of the device through the exhaust port 34a formed in the base 58 of the device. Although not shown,
A gas pipe is connected between the exhaust port 34a and the exhaust port 33.

Further, the gas disperser 47 and the rotary holder 34.
In order to prevent discharge from the side surface of the gas disperser 47 and the rotary holder 34, a dark shield 46 is provided on the side surface of the gas disperser 47 and the rotary holder 34 with a slight gap from the side surface. Next, FIG.
Details of the gas disperser 47 will be described with reference to (a) to (c). 3A is a sectional view, FIG. 3B is a top view of the receiving plate 108 of FIG. 3A, and FIG. 3C is a bottom view of the gas distributor 47. A sectional view of the portion of the receiving plate 108 of FIG. 3A corresponds to a sectional view taken along line III-III of FIG.
A sectional view of the entire gas disperser 47 of FIG. 3A is shown in FIG.
It corresponds to the IV-IV line cross section of.

As shown in FIGS. 3 (a) to 3 (c), the gas disperser 47 includes a base 105 and a plurality of gas discharge holes 1 in an annular shape.
And a circular conductive gas discharge plate 110 in which 11 is formed. The gas discharge hole 1 is formed in the center of the gas discharge plate 110.
11 is not formed. Mounting table 35 for gas disperser 47
When installed on the top, the gas release holes 111 face the wafer mounted along the circumference of the mounting table 35. Gas release plate 1
A peripheral portion 10 of the base 105 is fixedly attached to the base 105. Further, a through hole is formed in the central portion of the base 105 to serve as the first gas flow channel 48. The first gas flow path 48 serves as a gas outlet 106 at the end surface of the substrate 105, and a plurality of gas release holes 1 are provided through the second gas flow path 48.
It is connected to 11.

The second gas flow path 48 is the first gas flow path 4
The gas guided to the central portion by 8 is diverted in the radial direction, and the gas is further diverted toward the central portion and the peripheral direction midway from the central portion to the end portion. Then, the re-divided gas is released by the gas release holes 111 arranged in the annular region around the central portion. The specific structure of the second gas passage 48 is as follows. That is, the concave portion 1 is formed in the central portion of the substrate 105.
07 are formed, and the first gas flow path 4 is formed in the recess 107.
8 outlets 106 are formed. Further, a disk-shaped conductive receiving plate (receiving member) 108 having a size that fits into the recess 107 is provided on the base 10 around the outlet 106.
5 is attached. The position of the tip of the receiving plate 108 should be on the circumference drawn by the center of the rotating wafer.
In addition, the second gas flow path 4 is provided between the base 105 and the receiving plate 108.
8 and the radius of the recess 107 and the receiving plate 108
The radius of is set. In order to further improve the gas flow in the receiving plate 108, gas flow grooves 109 are radially formed from the center portion on the surface facing the outlet 106.

The gas emission plate 110 is in contact with the receiving plate 108 at the center of the gas emission plate 110. As a result, the base 105 and the gas discharge plate 110 are electrically connected to each other in the central portion and the peripheral portion. Gas disperser 47
In the case where electrical connection is established only between the peripheral portion of the base 105 and the gas release plate 110 that form the structure, the lead inductance of the gas release plate 110 causes a gap between the base 105 and the gas release plate 110 when high frequency power is applied. When the electric potential drop becomes larger in the central portion and therefore discharge occurs between the substrate 105 and the gas release plate 110 in the central portion of the gas disperser 47, as described above, the substrate 105 and the gas release plate 110 are separated from each other. Since electric conduction is established not only in the peripheral portion but also in the central portion, the potential drop between the substrate 105 and the gas release plate 110 becomes smaller, so that electric discharge between them can be prevented.

As described above, according to the embodiment of the present invention, since the mounting table 35 on which a plurality of wafers are mounted is configured to rotate relative to the gas disperser 47,
Even when the supply of the reaction gas from the gas disperser 47 is biased depending on the location, or even when the flow of the reaction gas is biased due to the asymmetry in the apparatus configuration, the mounting table 35 is moved in one direction or left and right during film formation. Since the supply of the reaction gas to the wafers is made uniform by rotating the wafers, it is possible to form films having a uniform film thickness and film quality on a plurality of wafers.

Further, by forming the counter electrodes, which also serve as the gas disperser 47 and the mounting table 35, respectively into a single electrode, the high frequency power supply 5 for supplying high frequency power to the electrodes.
4 is one. Further, by using the single heater 103 as the heater of the mounting table 35, only one power source is required to supply electric power thereto. As a result, it is possible to prevent the device from becoming large.

Further, since the mounting table 35 is provided with the heater 103, it is possible to rotate the mounting table 35 while heating the wafer. As a result, the wafer can be moved while maintaining the temperature of the wafer at a predetermined temperature. Further, the gas disperser 47 is provided with a gas release hole 111 in an annular region facing a plurality of wafers arranged along the circumference of the mounting table 35, and further, a gas introduction port 49 and an annular gas release hole 111. It has a narrow gas flow path 48 that connects with. Since the reaction gas is sent from the gas introduction port 49 to the gas release hole 111 through the narrow gas passage 48, the reaction gas introduced from the gas introduction port 49 is sent to the gas release hole 111 without spreading more than necessary. Therefore, the supply of the reaction gas to the gas release holes 111 is equalized. further,
Since the reaction gas is supplied almost directly above the wafer from the gas emission hole 111 facing the wafer, the supply amount of the reaction gas to the wafer can be made more uniform.

Next, a method for forming a film using the above plasma processing apparatus will be described with reference to FIGS. Trimethoxysilane ((CH ₃ O) ₃ SiH) is used among the alkoxysilanes as the silicon-containing reaction gas.
FIG. 5A is a cross-sectional view showing a state after the wiring layer is formed and before the silicon-containing insulating film is formed by the plasma CVD method. In the figure, 61 is a silicon substrate, 62
Is a base insulating film made of a silicon oxide film formed on the silicon substrate 61, and 63a and 63b are wiring layers formed on the base insulating film 62 and adjacent to each other at a predetermined interval. The above constitutes the wafers 55a to 55d as the substrates to be deposited.

First, the inside of the processing chamber 31 is evacuated and maintained at a predetermined pressure. Subsequently, the wafers 55 a to 55 d are loaded into the processing chamber 31, and the mounting table 3 of the rotary holder 34 is loaded.
Place on 5. Then, the wafer 55 is heated by the heater 103.
A to 55d are heated and maintained at a predetermined temperature. In the case of this embodiment, the temperature is set to 300 to 400 ° C. The heater 51 heats the gas disperser 47 to about 200 ° C.

Then, liquid trimethoxysilane kept at 10 ° C. is bubbled with an argon gas (carrier gas) having a flow rate of 100 sccm to generate an argon gas containing trimethoxysilane. A predetermined flow rate of N ₂ O gas as an oxidizing gas is added to this and introduced into the processing chamber 31 via the gas disperser 47. At this time, the pressure in the processing chamber 31 is maintained at about 1 Torr.

Next, the rotation holder 34 is rotated in both left and right directions for each rotation. Next, the frequency 13.56MHz,
A high frequency power of 2 kW is supplied to the gas disperser 47, and a frequency 380 is applied to the second electrode 102 of the mounting table 35.
It supplies high-frequency power of 2 kHz with a power of 2 kHz. By applying electric power to the gas disperser 47, the reaction gas is turned into plasma, and N ₂ O is dissociated into activated nitrogen N ^* and activated oxygen O ^* ,
The silicon-containing gas also dissociates into ions and electrons containing Si-H bonds. At this time, since high-frequency power is applied to the second electrode 102 of the mounting table 35, electrons are accumulated in the wafers 55a to 55d due to the difference in mobility of electrons and ions, and the wafers 55a to 55d have a negative voltage. -80 to -90V
Biased. As a result, the ions of the reaction gas turned into plasma are attracted onto the wafers 55a to 55d and react with the activated nitrogen and the activated oxygen, so that the wafers 55a to 55d.
SiO _x N _y covering the wiring layers 63a and 63b on 5d
The film 64 begins to form. Since the wafers 55a to 55d are biased to a negative voltage, the amount of ions reaching the wafer is increased, and the film formation rate is further increased. Further, since the reaction gas is blown out from directly above the wafers 55a to 55d, the supply amount of the reaction gas to the wafers 55a to 55d becomes more uniform. Further, since the wafers 55a to 55d rotate, even when the supply of the reaction gas from the gas disperser 47 is biased depending on the location or when the flow of the reaction gas is biased due to the asymmetry in the apparatus configuration, film formation is performed. By rotating the mounting table 35 to the left and right, the supply of the reaction gas to the wafers 55a to 55d is made uniform.

If this state is maintained for a predetermined time, the state shown in FIG.
As shown in (b), the SiO _x N _y film 64 having a predetermined thickness is formed.
Is formed. At this time, since the supply of the reaction gas to the wafers 55a to 55d is equalized, the plurality of wafers 5
A film having a uniform film thickness and film quality can be formed on 5a to 55d. Then, as shown in FIG. 5C, thermal CVD is performed.
A silicon oxide film 65 is formed on the SiO _x N _y film 64 by the method. That is, the wafers 55a to 55d are placed in an atmosphere of normal pressure.
And a reaction gas in which TE ₃ carried by a carrier gas is added with O ₃ + O ₂ gas containing O ₃ at a concentration of 6% while the wafer temperature is kept at about 400 ° C. Thermally decomposes and reacts with S
A silicon oxide film 65 is formed on the iO _x N _y film 64.
At this time, the underlying SiO _X N _y film 64 is TEOS + O ₃
Oxide film 6 by the thermal CVD method using a mixed gas of
5, the silicon oxide film 65 has a uniform film formation rate, abnormal growth is suppressed, and the step coverage of the silicon oxide film 65 is good.

After that, as shown in FIG. 5D, an SiO _x N _y film 66 is formed on the silicon oxide film 65 by the plasma CVD method under the same conditions as described above to complete an interlayer insulating film having a three-layer structure. To do. As described above, according to the embodiment of the present invention, in the film forming method by the plasma CVD method, the supply amount of the reaction gas supplied onto the wafers 55a to 55d is equalized, so that the surfaces of the wafers 55a to 55d are formed. SiO _x N _y films 64 and 66 having a uniform film thickness and film quality are formed on the film.

In addition, the bias of the wafers 55a to 55d
SiO formed by heating_XN _yThe membranes 64 and 66 are
It becomes more precise. (Second Embodiment) FIG. 6 shows a second embodiment of the present invention.
It is a side view which shows the plasma processing apparatus which concerns on a state. First
The difference from the embodiment is that it is attached to the rotation holder 34.
Support the rotating shaft 40 on the outside of the processing chamber 31.
It is that you are.

That is, a shield plate 44 for suppressing the flow of the reaction gas on the lower surface of the lower wall 34b of the rotary holder 34 and the upper surface of the base 58 of the apparatus shown in FIG. 1, and a ball for supporting the rotary holder 34. The bearing 45 is removed, and instead, as shown in FIG. 2, the rotating shaft 40 is rotatably supported by the ball bearing 60 outside the processing chamber 31 below the base 58. . In the figure, 59a is a bearing receiver attached to the rotary shaft 40, and 59b is a bearing receiver fixedly attached to a position different from the apparatus outside the processing chamber 31.

As a result, it is possible to prevent the influence of dust generation due to wear of the ball bearing 45 on the support portion of the rotary shaft 40 from reaching the inside of the apparatus. (Third Embodiment) FIG. 7 is a top view showing a portion of a mounting table of a plasma processing apparatus according to a third embodiment of the present invention. The difference from the first embodiment is that the heater 1
03a to 103d are independently installed on the respective mounting portions of the wafers 55a to 55d.

As a result, each of the wafers 55a to 55d can be independently heated. Therefore, the wafer 55
When the heat conductivity of each of the mounting portions a to 55d is different, or when the heat generation amount of the heater is different in a single heater, the heat generation amount of each heater 103a to 103d is adjusted and the wafers 55a to 55d are adjusted. It is possible to make the temperature uniform between them.

(Fourth Embodiment) FIG. 8A is a sectional view showing a gas disperser of a plasma processing apparatus according to a fourth embodiment of the present invention, and FIG. It is a bottom view of a). FIG. 8A corresponds to a cross section taken along line VV of FIG. 8B. The difference from the first embodiment is that a gas disperser 47a having a gas discharge part capable of supplying reaction gas independently at four locations is provided. 106 in the figure
a to 106d are a plurality of gas flow paths that are independently connected to the plurality of gas inlets of the gas disperser 47a and are formed so that reaction gases can flow independently of each other.
1a to 111d are a plurality of gas emission holes formed in the gas emission plate 110a of each gas emission part.

Therefore, even if the length, inner diameter, etc. of the gas passage of the manufactured gas disperser 47a are different depending on the location, each gas is adjusted by adjusting the flow rate of the reaction gas introduced from each gas inlet of the gas disperser 47a. It is possible to equalize the amount of the reaction gas released from the release unit. Thereby, it is possible to form a multi-layered film having a uniform film thickness and different film quality on the wafer.

Also in this case, since the counter electrodes are each composed of a single electrode, only one high frequency power source is required, and the size of the device can be suppressed. Further, the wafer can be moved and the film can be continuously formed while keeping the temperature of the wafer at a predetermined temperature. Thus, if the wafer temperature is set to a predetermined temperature and the gas flow rate and the like are set, it is not necessary to readjust the wafer temperature and the gas flow rate until the film formation is completed. It is possible to improve the accuracy of the film forming conditions without being affected by the fluctuation of

(Fifth Embodiment) FIGS. 9A and 9B.
[Fig. 8] is a bottom view showing a portion of a gas pipe connected to a gas disperser 47 of a plasma processing apparatus according to a fifth embodiment of the present invention. The difference from the first embodiment shown in FIG. 1 and FIG. 4 is that the gas pipe is formed of a conductor without using the insulator 50 in a part of the gas pipe, and the connecting portion of the high frequency power supply 54. That is, the gas pipe upstream of the above is processed into a coil shape. Note that FIG. 4 is a gas disperser 4 of FIG.
It is the figure which simplified the part of the gas piping connected to 7.

The gas pipe 112 formed in a coil shape has a function as a coil for blocking conduction of high frequency power,
Therefore, as shown in FIGS. 1 and 4, the high-frequency power supplied from the high-frequency power supply 54 is supplied to the gas pipe without the insulator 50 being interposed in a part of the gas pipe upstream of the connection portion of the high-frequency power supply 54. It is possible to prevent the gas from coming off to the gas introduction port 49 side.

The impedance of a specific example of the coil 112 formed of gas piping is calculated as follows. That is, the frequency of the high frequency power supply 54 is 13.56.
In the case of MHz, for example, the inner diameter of the coil 112 is 50 mm,
If the number of turns is 4.5 turns and the length is 40 mm, the coil 11
The impedance of 2 is about 110Ω. At this time,
Since the plasma resistance is estimated to be 1 Ω or less at the same frequency, the high frequency power is supplied to the gas disperser 47 side without passing through the gas introduction port 49 side of the gas pipe.

In the above embodiment, the gas dispersers 47 and 47a are fixed, and the mounting table 35 is rotated, but conversely, the mounting table 35 is fixed and the gas distributor 4 is rotated.
Even if 7, 47a is rotated, the same effect as in the above embodiment can be obtained.

[0058]

As described above, in the plasma processing apparatus of the present invention, the mounting table holding a plurality of objects to be processed is rotatably moved with respect to the gas disperser. Even if the flow of the reaction gas is uneven, the supply of the reaction gas to the object to be processed is equalized by rotating the mounting table in one direction or in both the left and right directions during film formation. A film having a uniform film thickness and film quality can be formed on the processing body.

Further, a single high-frequency power source is required by forming the counter electrodes, which also serve as the gas disperser and the mounting table, respectively into a single electrode. Further, by using a single heater for the mounting table, only one power source is required to supply power to it. As a result, the size of the device can be prevented from increasing. Furthermore, a single gas disperser having a gas inlet in the central portion is used, and the gas disperser has a ring-shaped gas discharge portion facing a plurality of objects to be processed arranged along the circumference of the mounting table. Further, it has a narrow gas flow path connecting the gas discharge part and the gas introduction port. Therefore, since the spread of the reaction gas is suppressed, the supply of the reaction gas to the gas releasing portion and the like is made uniform. Further, since the reaction gas is supplied almost directly above the object to be processed from these gas discharge parts and the like, the supply amount of the reaction gas to the object to be processed can be made more uniform.

Further, since the mounting table is provided with the heater, the object to be processed can be rotationally moved while keeping the temperature of the object to be processed at a predetermined temperature. Further, since the heaters are individually provided to the plurality of mounting portions of the mounting table, the heat generation amount of each heater can be adjusted to make the temperature of the object to be processed of each mounting portion uniform. Furthermore, by switching the reaction gas after forming one film, it is possible to continuously form a film of a type different from the movement of the object to be processed while keeping the temperature of the object to be processed at a predetermined temperature. . Thereby, high throughput can be obtained.

[Brief description of drawings]

FIG. 1 shows a plasma CV according to a first embodiment of the present invention.
It is a side view which shows the whole structure of D apparatus.

FIG. 2 (a) is a plan view showing details of a wafer mounting table of the plasma CVD apparatus according to the first embodiment of the present invention, and FIG. 2 (b) is II of FIG. 2 (a). It is a II sectional view.

FIG. 3 (a) is a sectional view showing details of a gas disperser of the plasma CVD apparatus according to the first embodiment of the present invention, and FIG. 3 (b) is a plan view of a receiving plate portion. (C) is a plan view. A cross-sectional view of the backing plate of FIG. 3A is shown in FIG.
3B corresponds to the section taken along the line III-III, and the sectional view of FIG. 3A corresponds to the section taken along the line IV-IV of FIG. 3C.

FIG. 4 is a plasma CV according to the first embodiment of the present invention.
It is a side view which shows in detail the gas piping part of the gas disperser of D apparatus.

FIG. 5 is a plasma CV according to the first embodiment of the present invention.
It is sectional drawing shown about the method of forming an insulating film using a D apparatus.

FIG. 6 is a plasma CV according to a second embodiment of the present invention.
It is a side view which shows the whole structure of D apparatus.

FIG. 7 is a plasma CV according to a third embodiment of the present invention.
FIG. 6 is a plan view showing details of a wafer mounting table of the D apparatus.

FIG. 8 (a) is a sectional view showing details of a gas disperser of a plasma CVD apparatus according to a fourth embodiment of the present invention, and FIG. 8 (b) is a plan view. FIG. 8 (a) is shown in FIG.
It corresponds to the VV line cross section of (b).

9 (a) is a side view showing details of a gas pipe portion of a gas disperser of a plasma CVD apparatus according to a fifth embodiment of the present invention, and FIG. 9 (b) is FIG. 9 (a). FIG.

FIG. 10 is a plan view showing the overall configuration of a multi-chamber CVD apparatus according to a conventional example.

FIG. 11 is a plan view showing the overall configuration of a walking beam type CVD apparatus according to a conventional example.

FIG. 12 (a) is a plan view showing an overall configuration of a multi-reactor CVD apparatus according to a conventional example, FIG.
FIG. 12B is a sectional view taken along the line I-I of FIG.

[Explanation of symbols]

31 processing chamber, 32 loading / unloading port, 33, 34a exhaust port, 34 rotation holder, 34a side wall, 34b lower wall, 35 mounting table, 36 insulator, 37 support rod, 38 wafer lifter, 39 wafer lift pin, 40 rotating shaft , 41, 42a, 42b wiring, 43 fluid magnetic shield, 43a magnet, 43b iron powder grease, 44 shielding plate, 45, 60 ball bearing, 46 dark shield, 47, 47a gas disperser, 48, 48a to 48d gas passage , 49 gas inlet, 50, 104 insulator, 51, 103, 103a to 103d heater, 52 cooler, 53 matching circuit, 54 high frequency power supply, 55a to 55d wafer (processed object), 56, 57, 113 valve, 58 base, 59a, 59b bearing receiver, 61 silicon substrate, 62 base insulating film, 63a, 63b wiring, 64, 66 SiO _x N _y film, 65 silicon oxide film, 101 conductive plate, 102 electrode, 105, 105a substrate, 106, 106a to 106d blowout port, 107 concave part, 108 receiving plate (Receiving member), 109 gas flow groove, 110, 110a gas release plate, 111, 111a to 111d gas release hole, 112 coiled gas pipe.

[Procedure amendment]

[Submission date] December 27, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction contents]

By using the walking beams 14a to 14h to sequentially rotate and move the wafers 15a to 15h, film formation is continuously performed and high throughput is obtained. By dividing the film formation and stacking the films formed by the reactors, it is possible to eliminate the difference in film thickness and film quality between the wafers 15a to 15h. As shown in FIG. 12, the multi-reactor batch type CVD apparatus has a plurality of wafer mounting portions 22a which also serve as electrodes for plasmaizing a reaction gas on a wafer mounting table 21 in a single processing chamber.
22d are individually provided. The wafer mounting table 21 is fixed, and the wafers 26a to 26d mounted on the wafer mounting portions 22a to 22d are lifted by a robot (not shown) before or after film formation so that the wafer mounting portion 22 can be lifted.
A to 22d are sequentially moved. Further, the shower head electrodes 23a to 23d for individually supplying the reaction gas and the high-frequency power to the wafer mounting portions 22a to 22d are provided on the wafer mounting portions 22a to 22d, respectively.
It is provided facing 2d.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuo Maeda 2-13-29 Konan, Minato-ku, Tokyo Inside Semiconductor Process Research Institute Co., Ltd. (72) Inventor Junichi Aoki 3-11-28 Canon, Mita, Minato-ku, Tokyo Selling stock company

Claims (11)

[Claims] 1. A gas disperser, which is a first electrode and discharges a reaction gas, and a second electrode, which is rotatable opposite to the gas disperser and has a plurality of electrodes arranged along the rotation direction. A plasma processing apparatus having a mounting table on which an object to be processed is mounted. 2. The plasma processing apparatus according to claim 1, wherein a high frequency power source for converting the reaction gas into plasma is connected to the first electrode. 3. The plasma according to claim 1 or 2, wherein an AC power source for applying a bias voltage to the object to be processed placed on the mounting table is connected to the second electrode. Processing equipment. 4. The gas disperser is connected to a gas inlet for introducing the reaction gas, a gas passage for introducing the reaction gas from the gas inlet, and the gas passage, and the gas disperser is mounted on the mounting table. It has a gas discharge part formed in a ring at a position facing the object to be processed.
The plasma processing apparatus according to any one of 1. 5. The gas disperser comprises a plurality of gas inlets capable of independently introducing different reaction gases, and a plurality of gas streams each independently introducing the reaction gas from the plurality of gas inlets. A path and a plurality of gas discharge portions that are independently connected to each of the plurality of gas flow paths and that are annularly arranged at a position facing the object to be processed that is annularly arranged on the mounting table. The plasma processing apparatus according to any one of claims 1 to 3, which is characterized. 6. The gas discharge part has a plurality of gas discharge holes distributed therein.
3. The plasma processing apparatus according to 1. 7. The mounting table according to claim 1, further comprising a single heater installed on the mounting table below the mounting portion of the object to be processed. Plasma processing equipment. 8. The mounting table according to claim 1, further comprising a plurality of heaters individually installed on the mounting tables below the mounting portions of the plurality of objects to be processed.
The plasma processing apparatus according to any one of 1. 9. The plasma processing apparatus according to claim 7, wherein the second electrode and the heater are formed on a common base made of an insulating material. 10. The gas disperser comprises an electrically conductive gas pipe having a coil-shaped portion that connects the gas emission hole or the gas emission group and the gas introduction port, and the gas disperser is more than the coil-shaped portion. The plasma processing apparatus according to claim 1, wherein a power supply for supplying high-frequency power is connected to the gas pipe on the downstream side. 11. The gas disperser and the mounting table are installed in a depressurizable processing chamber, and a rotating shaft is attached to the mounting table, and the rotating shaft is drawn out of the processing chamber and rotatable. The plasma processing apparatus according to claim 1, wherein the plasma processing apparatus is supported outside.