JP2975885B2 - Gas disperser and plasma processing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas disperser and a plasma processing apparatus, and more particularly, to a gas disperser having an electrode for applying a high-frequency power for converting a reaction gas into a plasma, and a plasma gas. The present invention relates to a plasma processing apparatus used for plasma processing for performing film or etching.

[0002]

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

In a multi-chamber type CVD apparatus, as shown in FIG. 10, since each of the processing chambers 3a to 3f is independently provided, various kinds of different processing can be performed and the flexibility is high. Furthermore, it is possible to provide a plasma CVD apparatus by providing a plasma generator in each of the processing chambers 3a to 3f. In FIG. 10, 1 is a load lock chamber, 2 is a robot installed in the load lock chamber 1, and 4 is a wafer 6a-6 in each of the processing chambers 3a-3f.
f is a robot that loads or unloads f.

As shown in FIG. 11, a continuous beam type continuous CVD apparatus comprises a wafer mounting table 12 having a plurality of wafer mounting sections 13a to 13h arranged in a single processing chamber 11, and wafers 15a to 15h. Walking beams 14a to 14h rotatable about a rotation axis while holding
And is installed. Further, each of the wafer mounting sections 13a to 13a-1
3h is provided with a heater. In addition, in FIG.
, A robot installed in the first load lock chamber 7, a second load lock chamber 10, a valve 9 a for opening and closing between the chamber 7 and the second load lock chamber 9, 9 b Is a valve that opens and closes between the second load lock chamber 10 and the processing chamber 11.

[0005] By sequentially rotating and moving the wafers 15a to 15h using the walking beams 14a to 14h, a film is continuously formed and a high throughput is obtained. By forming the film by dividing it and stacking the films formed by the respective reactors, the difference between the wafers 15a to 15h can be eliminated. Multi-reactor batch system C
In the VD apparatus, as shown in FIG. 12, a plurality of wafer mounting portions 22a to 22d each serving as an electrode for converting a reaction gas into plasma are individually provided on a wafer mounting table 21 in a single processing chamber. I have. Each of the wafers placed on the wafer placement units 22a to 22d is lifted by a robot (not shown) for each film formation, and sequentially moves on the wafer placement units 22a to 22d. Also, electrodes 23a to 23d with shower heads for individually supplying a reaction gas and high-frequency power to each of the wafer mounting portions 22a to 22d are provided on the wafer mounting portions 22a to 22d.
It is provided to face each of the wafer mounting portions 22a to 22d every 2d.

In the multi-reactor batch type CVD apparatus, the wafers 26a to 26d are transported to the plurality of wafer mounting portions 22a to 22d, respectively, and then a film forming process is collectively performed. Further, different types of reaction gases are supplied to the respective shower heads 23a to 23d, and the wafer 26
a to 26d, and lift the next wafer mounting portions 22a to 22d.
By moving to d, different types of multilayer films can be formed continuously. Further, a throughput proportional to the number of wafers 26a to 26d to be collectively processed can be obtained.

[0007] Among the above three types of CVD apparatuses, the multi-reactor batch type CVD apparatus can obtain the highest throughput. Although not shown in detail, the gas disperser used in the above-described plasma CVD apparatus has a base having a through hole for introducing a gas at a central portion thereof, and a gas releasing device for releasing the introduced gas, Contact is made at the periphery of the substrate. The gas disperser has a function as one of the counter electrodes for converting the reaction gas into plasma, a high frequency power supply is connected to the base, and high frequency power is supplied.

[0008]

However, in the multi-chamber type CVD apparatus, the robot 4 has one processing chamber 3.
a, the wafers 6a to 6f are unloaded and the next processing chamber 3
Since it is necessary to perform the operation of carrying the wafer into the chamber b, it takes a long time to carry the wafer, 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 supply systems of the reaction gas and the high-frequency power are different between the reactors, there is a specific difference in the supply amount of the reaction gas and the high-frequency power between the reactors, and the film thickness of the formed film among the wafers 6a to 6f. And the film quality is different.

In a plasma CVD apparatus, a high-frequency power supply for excitation or the like must be provided, and there is a problem that the apparatus becomes large. In the walking beam type continuous CVD apparatus, the reaction gas and the high-frequency power between the reactors cannot be separated due to the single processing chamber 11, so that different types 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 one film formation, the wafers 15a to 15h are moved.
Since 5h is separated from the mounting table, it cannot be avoided that the temperature of the wafers 15a to 15h drops. As a result, a temperature cycle is applied during the film formation, and there is a problem that a distortion remains in the formed film. Also, the wafer 15a
The film formation was interrupted during the movement of ~ 15h, and the wafer 1 was moved after the movement.
It is necessary to reheat so that the temperature of 5a to 15h becomes a predetermined temperature, and further wait for stabilization of the gas flow rate. For this reason, there is a problem that the processing time becomes longer, and as a result, a high throughput cannot be obtained.

[0010] Further, multi-reactor batch type CVD
In the apparatus, the wafers 26a to 26d
２２22d one after another, causing the same problem as in the walking beam type CVD apparatus. In addition, since the supply system of the reaction gas and the high frequency power is different between each reactor, the apparatus becomes large. In addition, there is an inherent difference in the supply amount of the reaction gas and the high-frequency power between the reactors, and the wafers 26a to 26
The thickness and quality of the formed film may be different between 6d.

In the gas disperser, when high-frequency power is applied, the high-frequency power is applied to the gas discharger from the base through its peripheral portion. However, a potential drop occurs in the gas discharging device due to the impedance of the gas discharging device with respect to the high-frequency power, and the potential difference between the base and the gas discharging device increases toward the center of the gas discharging device. For this reason, there is a problem that electric discharge may occur between the base and the gas discharge device depending on the magnitude of the high frequency power.

The above problem also occurs in an etching apparatus having a similar structure using a plasma gas, and it is desired to solve the problem. The present invention has been made in view of such a conventional problem, and it is possible to uniformly discharge a reaction gas onto a plurality of processing objects arranged in an annular shape with respect to an outlet of the reaction gas, thereby enabling discharge. Gas disperser that can be suppressed,
In addition, a film having a uniform film thickness, film quality, or the like or a multilayer film of a different type can be formed over a plurality of objects to be processed, or uniform etching can be performed, so that an increase in the size of the apparatus can be prevented. It is an object to provide a plasma processing apparatus.

[0013]

According to a first aspect of the present invention, there is provided a gas disperser, wherein a concave portion is formed in a region from a central portion to a middle portion from an end portion. A base having a through-hole for introducing a gas into the recess, a gas receiving member installed in the concave portion and diverting the introduced gas in a radial direction, A gas discharger that re-divides the gas in the direction and discharges the re-divided gas from an annular region around the central portion, wherein the gas discharger is provided at an outer peripheral portion of the gas discharger. 3. The gas disperser according to claim 1, wherein the gas disperser is in contact with the base, and is in contact with the base via the receiving member at an inner peripheral portion of the gas discharging device. In this regard, a plurality of gas discharge holes are divided in the annular region. According to a third aspect of the present invention, there is provided the gas disperser according to the first or second aspect, wherein the gas disperser has a surface on which an annular region of the gas discharging tool is formed. The invention according to claim 4 is characterized by being rotatable about an axis substantially perpendicular to the plasma processing apparatus, and relates to a plasma processing apparatus.
The gas disperser according to any one of the above, and a second electrode, wherein the object to be processed placed opposite to the gas disperser and fixedly installed and placed facing the annular region. The invention according to a fifth aspect relates to the plasma processing apparatus according to the fourth aspect, wherein the gas disperser converts the gas into plasma. A high frequency power supply is connected, and the invention according to claim 6 relates to the plasma processing apparatus according to claim 4 or 5, wherein a bias voltage is applied to the object to be processed mounted on the mounting table. An AC power supply to be applied is connected to the mounting table.

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 object to be processed is arranged around the gas outlet, Since the reaction gas is released from a position off the center of the processing object, the gas is supplied to the surface of the processing object in the radial direction of the mounting table while the reaction gas spreads from the center of the mounting table toward the periphery. Deviations in volume may occur.

In the gas disperser of the present invention, a recess is formed in a region from the center to the middle from the end, and a base having a through hole through which gas is introduced into the recess, and a base provided in the recess and introduced. Receiving member for diverting the discharged gas in the radial direction, and a gas discharging device for re-dividing the gas guided by the receiving member in the central direction and the peripheral direction, and releasing the re-diverted gas from an annular region around the central portion. In the gas disperser provided with the outlet, the gas discharging device is in contact with the base at the outer peripheral portion of the gas discharging device, and is in contact with the base via the receiving member at the inner peripheral portion of the gas discharging device. That is, the gas guided to the central portion by the through hole of the concave portion is diverted in the radial direction, and the gas is formed by the gas flow path formed by the base wall of the concave portion and the gas receiving member in the middle from the central portion to the end portion. Is re-divided in the central direction and the peripheral direction, and the re-diverted gas is discharged from the annular region around the central portion.

Therefore, the gas passing through the through hole of the concave portion is further sent to the annular region of the gas releasing device through the gas flow path, so that the gas discharged from the through hole of the concave portion does not spread more than necessary. Sent to Therefore, the supply of gas to the annular region from which gas is released is equalized. Further, since the gas receiving member for expanding the gas emitted from the through hole of the concave portion in the radial direction is provided, the gas can be discharged in a state where the gas is spread in advance. For this reason, the gas supply amount to the peripheral portion can be made more uniform as compared with the case where the gas is directly discharged from the through hole of the concave portion.

Further, when the gas disperser also serves as the counter electrode of the plasma processing apparatus, the gas is turned into plasma by bringing the base of the gas disperser into contact with the gas discharger not only at the peripheral part but also at the central part of the base. When a high-frequency power source is connected to the base for supplying high-frequency power, the potential difference between the base and the gas discharger can be further reduced as compared with the case where the high-frequency power is supplied only at the peripheral portion. For this reason, discharge between them can be prevented.

The plasma processing apparatus of the present invention has the above-mentioned gas disperser, and has a mounting table on which a plurality of objects to be processed are mounted so as to face a gas discharge device formed in the annular region. Therefore, the gas is released from the gas release tool almost immediately above the object to be processed, and the amount of gas supply to the object to be processed can be further equalized. Thus, a film having a uniform thickness and quality can be formed on a plurality of objects to be processed.

Further, even when the supply of gas from the gas disperser is deviated depending on the location, or when the gas flow is deviated due to asymmetry in the apparatus configuration, the gas disperser can be used during film formation. By rotating around an axis substantially perpendicular to the surface on which the annular region is formed, the supply of the reaction gas to the object to be processed is equalized, and a film having a uniform thickness and quality is formed on a plurality of objects to be processed. Can be formed. Further, by connecting an AC power supply for applying a bias voltage to the object to be processed to the electrode of the mounting table, active particles can be collected by an attractive force of an electric field, thereby increasing a film forming rate and an etching rate, and further increasing a dense film. Can be formed.

Further, by forming the counter electrodes (first and second electrodes) which also serve as the gas disperser and the mounting table, respectively,
Only one high frequency power supply is required. This can suppress an increase in the size of the device.

[0021]

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

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

The gas distributor 47 has a function as one electrode (first electrode) of the counter electrode for converting the reaction gas into plasma, and is made of a conductor. A high-frequency power supply 54 for converting the reaction gas into plasma is connected to a conductive gas pipe connected to the gas distributor 47 via a matching circuit 53. 13.56 MHz is used as the frequency of the high frequency power supply 54. In some cases, a frequency of 100 kHz or another frequency may be used as the frequency of the high-frequency power supply 54. Further, the gas inlet 49
The conductive gas pipe on the side is grounded. The reason why the gas pipe is provided is to prevent a person who touches a gas cylinder or the like connected to the gas pipe from receiving an electric shock. Also, the reason that a part of the gas pipe is made of the insulator 50 is that if a conductor is used for the entire gas pipe, the high-frequency power is not supplied to the gas distributor 47 as an electrode, Inlet 4
This is to exit to the direction of No. 9.

The rotation holder 34 includes a mounting table 35 and a side wall 34.
a, the lower wall 34b, and the rotating shaft 40.
It is rotated in one direction or both left and right directions by the rotation shaft 40. Further, a heater 51 is attached to a surface of the gas distributor 47 opposite to the gas discharge surface. This is generated by the reaction gas released from the gas distributor 47,
In addition, since the reaction product adhering to the gas disperser 47 is soft as it is and easily peels off to form 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.

The details of the mounting table 35 are shown in FIGS. 2 (a) and 2 (b). FIG. 2A is a top view, and FIG. 2B is a 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 provided on the surface of the mounting table 35, and a second electrode made of tantalum or tungsten for contacting this conductive plate 101 to convert the reaction gas into plasma. 102 is embedded. The second electrode 102 has a function as another electrode of the counter electrode. Further, an insulator 10 is provided below the mounting table 35 below the second electrode 102.
4 is a heater 10 made of tantalum or tungsten
3 is embedded. The insulator 104 is a conductive plate 10
The first and second electrodes 102 and the heater 103 are made of an insulating material having substantially the same thermal expansion coefficient as tantalum or tungsten as a material of the heater 103, for example, alumina ceramic.

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 supply (not shown). During plasma generation, high-frequency power of a frequency of, for example, 380 kHz is supplied to the first electrode 102 to supply the wafers 55a to
55d is biased 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, thereby heating the wafers 55a to 55d.

The film forming rate can be increased by biasing the wafers 55a to 55d to a negative voltage.
The density of the formed film can be increased by biasing and heating the wafers 55a to 55d to a negative voltage. The mounting table 35 is created as follows. That is, the heater 103 is placed on a first green sheet of alumina, and the heater 103 is covered with a second green sheet made of alumina.
Further, the second electrode 102 is placed thereon. And the second
After the third electrode 102 is covered 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. Subsequently, after the conductive plate 101 is placed on the second electrode 102 and the third green sheet around the second electrode 102, the green sheet is cured by heating. Thus, 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 thermal stress due to the difference in the coefficient of thermal expansion increases.
It is possible to suppress cracking of the ceramic due to heating of the ceramic.

When the wirings 41, 42a, 42b are directly connected to the high frequency power supply and the DC power supply, the mounting table 35
The wires 41, 42a, and 42b are twisted by the rotation of, but the wires 41, 42a, and 42b can be prevented from being twisted by repeating the rotation of the mounting table 35 in the same order of rotation. In addition, high-frequency power supply and DC power supply and wirings 41 and 42 are provided.
If the connection to the wires 41, 42a, 42b can be prevented by a contact (rotary connector) attached to both the power supply side and the rotating shaft 40 side, the wires 41, 42a, 42b can be prevented.

Further, as shown in FIG. 1, a wafer lifter 38 for attaching and detaching the wafer 55c from the mounting table 35 is provided below the mounting table 35. Wafer lifter 38
Is pushed up, the wafer lift pins 39 inserted into the through holes formed in the mounting table 35 cause the wafer 55c to separate from the mounting table 35. Further, since the temperature of the mounting table 35 is increased by heating, for example, the iron powder grease 43b of the fluid magnetic shield 43 provided below the mounting table 35 to keep the gap between the rotary shaft 40 and the device airtight is heated. May be deteriorated. In order to avoid this, it is necessary to suppress the transmission of heat to the lower side of the device as much as possible. Therefore, the mounting table 35 is an insulator 36 for preventing heat conduction and suppressing heat radiation.
And is supported at several places by a thin support rod 37 made of stainless steel, and is kept as far away from the lower part of the apparatus as possible.
The fluid magnetic shield 43 includes a magnet 43a and iron powder grease 43b. For example, as shown in the figure, in order to seal a gap between the rotating shaft 40 and the base 58 of the apparatus, an iron powder grease is added to 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 in the processing chamber 31 is maintained.

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

Further, the rotation holder 34 is held at a predetermined distance from a base 58 of the apparatus by the support of a ball bearing 45. A plurality of screen-shaped shielding plates 44 are formed concentrically on the lower surface of the lower wall 34b of the rotation holder 34 and the upper surface of the base 58, respectively, and mesh with each other in a comb shape to rotate the rotation holder 34. The gap between the shielding plates 44 is narrow, and the cross-sectional shape of the gap is bent several times to form a zigzag shape. For this reason, the conductance of the gap is small, and the reaction gas that becomes unnecessary after being supplied to the wafers 55a to 55d hardly flows through this gap. In addition, the passage of particles generated by the reaction of the reaction gas is suppressed. Thus, the lower wall 34b of the rotary holder 34 and the base 5 of the apparatus are located downstream of the shielding plate 44.
The reaction product can be prevented from adhering to the ball bearing 45 sandwiched between the ball bearings 8, and furthermore, contamination of the iron powder grease 43b and the like by particles can be suppressed. Also, a small amount of the reactant gas passing through them is exhausted from the exhaust port 33 of the apparatus through the exhaust port 34a formed in the base 58 of the apparatus. Although not shown,
The exhaust port 34a and the exhaust port 33 are connected by a gas pipe.

Further, the gas disperser 47 and the rotation holder 34
In order to prevent electric discharge from the side surface, a dark shield 46 is provided on the side surface of the gas distributor 47 and the rotary holder 34 with a slight gap from the side surface. Next, FIG.
Details of the gas distributor 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 cross-sectional view of a portion of the receiving plate 108 in FIG. 3A corresponds to a cross section taken along line III-III in FIG.
FIG. 3C is a cross-sectional view of the entire gas distributor 47 of FIG.
IV-IV section.

As shown in FIGS. 3 (a) to 3 (c), the gas distributor 47 comprises a base 105 and a plurality of gas discharge holes 1 in an annular shape.
And a conductive gas release plate 110 having a circular shape on which is formed. Gas release hole 1 is provided at the center of gas release plate 110.
11 is not formed. The gas disperser 47 is mounted on the mounting table 35.
When installed above, the gas discharge holes 111 face the wafer placed along the circumference of the mounting table 35. Gas release plate 1
Reference numeral 10 denotes a peripheral portion of the base 105, which is fixed and attached to the base 105. In addition, a through hole is formed in the center of the base 105, and serves as a first gas flow path 48. The first gas flow path 48 serves as a gas outlet 106 at the end face of the base 105, and a plurality of gas discharge holes 1 through the second gas flow path 48.
Connected to 11.

The second gas passage 48 is connected to the first gas passage 4
8 divides the gas guided to the central portion in the radial direction, and further re-divides the gas toward the central portion and the peripheral direction in the middle from the central portion to the end. Then, the re-diverted gas is discharged by the gas discharge holes 111 arranged in the annular region around the central portion. The specific structure of the second gas flow path 48 is as follows. That is, the concave portion 1 is provided at the center of the base 105.
07 is formed, and the first gas passage 4
Eight outlets 106 are formed. Further, a disk-shaped conductive receiving plate (receiving member) 108 having a size enough to enter the concave portion 107 is provided on the base 10 around the outlet 106.
5 is attached. The center of the wafer, on which the tip of the receiving plate 108 is substantially rotated, is positioned on the drawn circle,
And the second gas flow path 4 between the base 105 and the receiving plate 108.
8 so that the radius of the concave portion 107 and the receiving plate 108 are formed.
Is set. In order to further improve the gas flow in the receiving plate 108, a gas flow groove 109 is formed radially from the center on the surface facing the outlet 106.

The gas discharge plate 110 is in contact with the receiving plate 108 at the center of the gas discharge plate 110. As a result, electrical continuity is established between the base 105 and the gas release plate 110 at the central portion and the peripheral portion. Gas disperser 47
When conduction is established only at the peripheral portion between the base 105 and the gas release plate 110, when the high-frequency power is applied, the lead inductance of the gas release plate 110 causes a gap between the base 105 and the gas release plate 110. As described above, when the potential drop becomes larger in the central portion and discharge occurs between the base 105 and the gas discharge plate 110 in the center of the gas distributor 47, the base 105 and the gas discharge plate 110 Since conduction is established in the central portion in addition to the peripheral portion, the potential drop between the base 105 and the gas release plate 110 becomes smaller, so that discharge during that period 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 rotated with respect to the gas distributor 47,
Even when the supply of the reaction gas from the gas disperser 47 is uneven depending on the location, or when the flow of the reaction gas is uneven due to asymmetry in the apparatus configuration, the mounting table 35 is moved in one direction or left and right during the film formation. By rotating, the supply of the reaction gas to the wafers is equalized, so that a film having a uniform film thickness and quality can be formed on a plurality of wafers.

Further, by using a single electrode for each of the opposite electrodes which also serve as the gas distributor 47 and the mounting table 35, a high-frequency power source 5 for supplying high-frequency power to the electrodes is provided.
4 is enough. Furthermore, since the heater of the mounting table 35 is a single heater 103, only one power source is required to supply power thereto. This can prevent the device from becoming large.

Further, since the mounting table 35 includes the heater 103, the mounting table 35 can be rotated while the wafer is heated. Thus, 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 discharge hole 111 in an annular region facing a plurality of wafers arranged along the circumference of the mounting table 35, and further, a gas inlet 49 and an annular gas discharge hole 111. And a narrow gas flow path 48 connecting the two. Since the reaction gas is sent from the gas inlet 49 to the gas discharge hole 111 through the narrow gas flow path 48, the reaction gas introduced from the gas inlet 49 is sent to the gas discharge hole 111 without spreading more than necessary. Thus, the supply of the reaction gas to the gas discharge holes 111 is equalized. further,
Since the reactant gas is supplied almost directly above the wafer from the gas discharge holes 111 facing the wafer, the supply amount of the reactant gas to the wafer can be further equalized.

Next, a method of forming a film using the above-described plasma processing apparatus will be described with reference to FIGS. Trimethoxysilane ((CH ₃ O) ₃ SiH) among alkoxysilanes is used as the silicon-containing reaction gas.
FIG. 5A is a cross-sectional view showing a state after a wiring layer is formed and before a silicon-containing insulating film is formed by a 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 a silicon substrate 61, and 63a and 63b are wiring layers formed on the base insulating film 62 and adjacent 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 rotation 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 300 to 400 ° C. The heater 51 heats the gas distributor 47 to about 200 ° C.

Next, liquid trimethoxysilane kept at 10 ° C. is bubbled with an argon gas (carrier gas) at a flow rate of 100 sccm to generate an argon gas containing trimethoxysilane. A predetermined flow rate of N ₂ O gas is added thereto as an oxidizing gas, and the oxidizing gas is introduced into the processing chamber 31 through the gas distributor 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 the left and right directions for each rotation. Next, at a frequency of 13.56 MHz,
A high-frequency power of 2 kW is supplied to the gas distributor 47 and a frequency of 380 is applied to the second electrode 102 of the mounting table 35.
High frequency power of 2 kHz and 2 kHz is supplied. The reaction gas is turned into plasma by application of electric power to the gas disperser 47, and N ₂ O is dissociated into activated nitrogen N ^* and activated oxygen O ^* ,
The silicon-containing gas also dissociates into ions containing Si—H bonds and electrons. At this time, since high-frequency power is applied to the second electrode 102 of the mounting table 35, electrons are accumulated on the wafers 55a to 55d due to the difference in mobility between the electrons and the ions, and the wafers 55a to 55d have a negative voltage. -80 to -90V
Biased. As a result, the ions of the reaction gas that have been turned into plasma are attracted onto the wafers 55a to 55d and react with activated nitrogen or activated oxygen.
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 that reach the wafers increases, and the film formation rate increases. Further, since the reaction gas is blown from almost right above the wafers 55a to 55d, the supply amounts of the reaction gas to the wafers 55a to 55d become more uniform. Further, since the wafers 55a to 55d rotate, even when the supply of the reaction gas from the gas disperser 47 is deviated depending on the location or the flow of the reaction gas is deviated due to asymmetry in the apparatus configuration, the film formation is performed. By rotating the mounting table 35 left and right inside, the supply of the reaction gas to the wafers 55a to 55d is equalized.

When this state is maintained for a predetermined time, FIG.
As shown in FIG. 2B, a SiO _x N _y film 64 having a predetermined thickness is formed.
Is formed. At this time, the supply of the reaction gas to the wafers 55a to 55d is equalized.
A film having a uniform thickness and quality can be formed on 5a to 55d. Next, as shown in FIG.
By law a silicon oxide film 65 on the SiO _X N _y film 64. That is, the wafers 55a to 55d are placed in a normal pressure atmosphere.
Placed, while maintaining the wafer temperature at about 400 ° C., by introducing a reaction gas was added O ₃ + O ₂ gas containing O ₃ at a ratio of TEOS concentration 6% carried by the carrier gas, reaction gas Is thermally decomposed and reacted to form S
On iO _X N _y film 64 to form a silicon oxide film 65.
At this time, the underlying SiO _X N _y film 64 is TEOS + O ₃
Oxide film 6 by thermal CVD using a mixed gas of
5, the film formation rate of the silicon oxide film 65 becomes uniform, abnormal growth is suppressed, and the step coverage of the silicon oxide film 65 is also good.

Thereafter, as shown in FIG. 5D, when 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 above, an interlayer insulating film having a three-layer structure is completed. I do. As described above, according to the embodiment of the present invention, in the film forming method by the plasma CVD method, the supply amounts of the reactant gases supplied onto the wafers 55a to 55d are equalized, so that the surface of the wafers 55a to 55d Is formed with SiO _x N _y films 64 and 66 having a uniform thickness and film quality.

The bias of the wafers 55a to 55d is
SiO formed by heating_XN _yMemories 64 and 66
It becomes more precise. (Second Embodiment) FIG. 6 shows a second embodiment of the present invention.
FIG. 2 is a side view showing the plasma processing apparatus according to the embodiment. First
The difference from the embodiment is that the
The rotating shaft 40 supported outside the processing chamber 31
It is that you are.

That is, a shielding 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 drawing, reference numeral 59a denotes a bearing receiver attached to the rotating shaft 40, and reference numeral 59b denotes a bearing receiver fixedly attached to a location outside the processing chamber 31 different from the apparatus.

As a result, it is possible to prevent the influence of dust generation due to the abrasion of the ball bearing 45 on the support of the rotating shaft 40 from affecting the inside of the apparatus. (Third Embodiment) FIG. 7 is a top view showing 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.

Thus, each of the wafers 55a to 55d can be separately and independently heated. Therefore, the wafer 55
In the case where the thermal conductivity of each of the mounting portions a to 55d is different or the amount of heat generated by the heater is different with a single heater, the amount of heat generated by the heaters 103a to 103d is adjusted to adjust the wafers 55a to 55d. It is possible to equalize the temperature during the period.

(Fourth Embodiment) FIG. 8A is a sectional view showing a gas distributor 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 in FIG. 8B. The difference from the first embodiment is that a gas disperser 47a having a gas discharge part capable of supplying a reaction gas independently at four locations is provided. In the figure, 106
Reference numerals a to 106 d denote a plurality of gas flow paths which are formed so as to allow the reaction gas to flow independently and are respectively connected to the plurality of gas inlets of the gas distributor 47 a independently.
1a to 111d are a plurality of gas discharge holes formed in the gas discharge plate 110a of each gas discharge portion.

Therefore, even if the length and the inner diameter of the gas flow path of the gas distributor 47a differ depending on the place, the flow rate of the reaction gas introduced from each gas inlet of the gas distributor 47a is adjusted. It is possible to equalize the amount of the reaction gas released from the discharge section. As a result, it is possible to form a multilayer film having a uniform thickness and different film quality on the wafer.

Also in this case, since each of the opposing electrodes is composed of a single electrode, only one high-frequency power source is required, and the size of the apparatus can be suppressed. Further, while the temperature of the wafer is kept at a predetermined temperature, the movement of the wafer and the continuous film formation become possible. Accordingly, if the temperature of the wafer 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. And the accuracy of the film forming conditions can be improved.

(Fifth Embodiment) FIGS. 9A and 9B
FIG. 13 is a bottom view showing a portion of a gas pipe connected to a gas distributor 47 of a plasma processing apparatus according to a fifth embodiment of the present invention. The difference from the first embodiment shown in FIGS. 1 and 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 connection part of the high-frequency power source 54 That is, the gas pipe upstream of the pipe is processed into a coil shape. FIG. 4 shows the gas distributor 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 preventing conduction of high frequency power.
Therefore, as shown in FIG. 1 and FIG. Can be prevented from leaking to the gas introduction port 49 side.

With respect to a specific example of the coil 112 formed by a gas pipe, its impedance is calculated as follows. That is, the frequency of the high frequency power supply 54 is 13.56.
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
2 has an impedance of about 110Ω. At this time,
At the same frequency, the resistance of the plasma is estimated to be 1 Ω or less, so that the high-frequency power is almost supplied to the gas distributor 47 without passing through the gas inlet 49 of the gas pipe.

In the above embodiment, the gas dispersers 47 and 47a are fixed, and the mounting table 35 is rotated. On the contrary, the mounting table 35 is fixed and the gas disperser 4 is fixed.
The same effect as in the above-described embodiment can be obtained even by rotating 7, 47a.

[0057]

As described above, in the gas distributor according to the present invention, the concave portion is formed in the region from the center portion to the middle portion from the end portion, and the base having the through hole for introducing gas into the concave portion, A gas receiving member installed in the inside and diverting the introduced gas in the radial direction, and the gas guided by the receiving member is re-divided in the central direction and the peripheral direction, and the re-divided gas is distributed around the central portion. A gas discharging device having a gas releasing device that discharges from the annular region, wherein the gas discharging device contacts the base at an outer peripheral portion of the gas discharging device, and contacts the base via a receiving member at an inner peripheral portion of the gas discharging portion. In contact.

Therefore, the gas discharged from the through-hole of the concave portion is sent to the gas discharging device without spreading more than necessary, so that the gas supply to the gas discharging device is equalized. Furthermore, since the gas receiving member has a gas receiving member for expanding the gas emitted from the through hole of the concave portion in the radial direction, the gas can be supplied to the annular region of the gas discharging tool in a state where the gas is spread in advance. The gas is released and the gas supply amount to the wafer can be made more uniform.

Further, by contacting the gas releasing device with the substrate not only at the peripheral portion but also at the center portion of the substrate, when high-frequency power for converting the gas into plasma through the substrate is supplied to the gas discharging device, The electric potential difference between the gas discharging device and the gas discharging device can be further reduced, and discharge between them can be prevented. In the plasma processing apparatus of the present invention, the gas discharging device includes the mounting table on which the plurality of objects to be processed are mounted so as to face the annular region of the gas discharging device. The gas is released almost immediately above the object to be processed, and the supply amount of the reaction gas to the object is evened out, forming a uniform film with a uniform thickness and quality on a plurality of objects. can do.

Even when the supply of the reaction gas from the gas disperser is uneven depending on the location, or when the flow of the reaction gas is uneven due to the asymmetry of the apparatus configuration, the gas disperser is operated during the film formation. By rotating the discharge tool about an axis substantially perpendicular to the surface on which the annular region is formed, the supply of the reaction gas to the object to be processed is equalized, and the film thickness and the film quality are uniform on a plurality of objects to be processed. A film can be formed. Furthermore,
By connecting an AC power supply that applies a bias voltage to the object to be processed to the electrode of the mounting table, active particles can be collected by the attractive force of the electric field, increasing the film formation rate and etching rate, and forming a denser film. It is possible to do.

Further, by using the opposite electrodes (first and second electrodes) which also serve as the gas disperser and the mounting table,
Only one high frequency power supply is required. This can suppress an increase in the size of the device.

[Brief description of the 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. 2A 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. 2B is a plan view II of FIG. FIG. 2 is a sectional view taken along line II.

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

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

FIG. 6 shows 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 shows a plasma CV according to a third embodiment of the present invention.
It is a top view which shows the detail of the mounting table of the wafer of D apparatus.

FIG. 8A 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. 8B is a plan view. FIG. 8A shows FIG.
This corresponds to a cross section taken along line V-V in (b).

FIG. 9A 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. 9B is a view showing FIG. 9A. FIG.

FIG. 10 is a plan view showing an overall configuration of a conventional multi-chamber CVD apparatus.

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

FIG. 12A is a plan view showing an entire configuration of a conventional multi-reactor CVD apparatus, and FIG.
FIG. 12B is a sectional view taken along line II 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 rotation 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 flow path , 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 (workpiece), 56, 57, 113 valve, 58 base, 59a, 59b bearing receiver, 61 silicon substrate, 62 base insulating film, 63a, 63 b wiring, 64, 66 SiO _x N _y film, 65 a silicon oxide film, 101 a conductive plate, 102 electrode, 105 and 105a substrate, 106,106A～106d air outlet, 107 recess, 108 receiving plate (Receiving member), 109 gas flow grooves, 110, 110a gas discharge plates, 111, 111a to 111d gas discharge holes, 112 coiled gas pipes.

Continuation of the front page (51) Int.Cl. ⁶ Identification code FI H05H 1/46 H01L 21/302 C (72) Inventor Kazuo Maeda 2-13-29 Konan, Minato-ku, Tokyo Inside Semiconductor Process Research Laboratories (72 ) Inventor Junichi Aoki 3-11-28 Mita, Minato-ku, Tokyo Cannon Sales Co., Ltd. (56) References JP-A-1-89957 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB Name) C23C 16/00-16/56 C23F 4/00-4/04 H01L 21/205 H01L 21/3065 H01L 21/31 H05H 1/46

Claims (6)

(57) [Claims] 1. A base having a through hole through which a gas is introduced into a recess in a region from the center to an intermediate portion from an end, and a base provided in the recess, wherein the introduced gas is removed. A gas receiving member that diverges in the radial direction, and a gas that re-divides the gas guided by the receiving member in the central direction and the peripheral direction, and discharges the re-divided gas from an annular region around the central portion. In the gas disperser provided with a discharging device, the gas discharging device is in contact with the base at an outer peripheral portion of the gas discharging device, and is connected to the base via the receiving member at an inner peripheral portion of the gas discharging device. A gas disperser characterized by being in contact. 2. The gas distributor according to claim 1, wherein a plurality of gas discharge holes are distributed in the annular region. 3. The gas disperser according to claim 1, wherein the gas disperser is rotatable about an axis substantially perpendicular to a surface on which the annular region of the gas discharging device is formed. Gas disperser. 4. The gas dispersion device according to claim 1, further comprising: a second electrode, the annular region facing and fixed to the gas dispersion device. And a mounting table for the object to be processed having a mounting portion for the object to be processed to be placed facing the plasma processing apparatus. 5. The plasma processing apparatus according to claim 4, wherein a high-frequency power supply for converting the gas into plasma is connected to the gas disperser. 6. The plasma processing apparatus according to claim 4, wherein an AC power supply for applying a bias voltage to the object mounted on the mounting table is connected to the mounting table. .