JP2002190473A - Plasma processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma processing apparatus, capable of preventing the processed surface of the object to be processed from contaminating with fine particles or the like. SOLUTION: This plasma processing apparatus comprises a processing chamber 2' made of an electrically conductive material, an exhaust pump for exhausting the processing chamber, a gas supply means for introducing gases into the processing chamber, a loading pedestal 4' on which the object to be processed is loaded in the processing chamber, an RF antenna 6', formed into a planar spiral-coiled shape via an insulation material outside the processing chamber, and a support mechanism 76 for supporting the object to be processed from the bottom side, wherein the loading plane for the object faces downward or sideways with respect to the ground plane.

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.

[0002]

2. Description of the Related Art Conventionally, a parallel plate type plasma processing apparatus using a high frequency (RF) has been widely used as an apparatus for performing a plasma processing on an object to be processed, for example, a semiconductor wafer in a processing chamber. Reactive ion etching (R) in which two parallel plate type electrodes are arranged in a processing chamber
In the case of the IE) apparatus, a plasma is generated between the two electrodes by applying a high frequency to one or both electrodes, and a self-bias potential difference between the plasma and the object to be processed causes A plasma flow is incident on the processing surface of the object to be processed to perform an etching process.

However, in a conventional plasma processing apparatus such as the above-described parallel plate type plasma processing apparatus, ultra-fine processing in a submicron unit or a sub-half micron unit required as the semiconductor wafer is highly integrated. Is difficult to implement. In other words, in order to perform such a process using a plasma processing apparatus, it is important to control high-density plasma with high precision in a low-pressure atmosphere, and the plasma has a large area that can support a large-diameter wafer. It must be highly uniform. Further, in a plasma processing apparatus using an electrode, the electrode itself becomes a source of heavy metal contamination when plasma is generated, and this has been a problem particularly when ultrafine processing is required.

[0004] In order to establish a new plasma source in response to such technical requirements, a number of approaches have been taken from various angles so far. For example, EP-A-379828 describes the following. A high-frequency induction plasma generator using a high-frequency antenna is disclosed. In this high-frequency induction plasma generator, one surface of a processing chamber opposed to a wafer mounting table is formed of an insulator such as quartz glass, and a high-frequency antenna composed of, for example, a spiral coil is attached to an outer wall surface thereof. Is applied, a high-frequency electromagnetic field is formed in the processing chamber, and electrons flowing in the electromagnetic field space collide with neutral particles of the processing gas, thereby ionizing the gas and generating plasma.

[0005]

When a silicon oxide film is etched with a CF-based processing gas, for example, using a high-frequency induction plasma as described above, an etching target is removed at a high etching rate. At the same time, it is necessary to accurately form the etching shape into a vertical or substantially tapered shape, and for that purpose, it is necessary to establish a technique for controlling the starting point and the ending point of the etching with high accuracy.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems that occur particularly when etching is performed by a high-frequency induction type plasma processing apparatus, and an object of the present invention is to provide a high-frequency induction type plasma processing apparatus. An object of the present invention is to provide a plasma processing apparatus having a new and improved control method for securing a good etching shape at a high etching rate when performing an etching process by the apparatus.

[0007]

In order to solve the above-mentioned problems, a plasma processing apparatus constructed according to an aspect of the present invention comprises a processing container made of a conductive material and an exhaust gas for exhausting the inside of the processing container. A pump, a gas supply means for introducing gas into the processing chamber, a mounting table provided in the processing chamber for mounting an object to be processed, and a planar spiral coil outside the processing chamber via an insulating material. It is characterized by comprising a formed high-frequency antenna and a support mechanism for supporting the object to be processed from below.

According to another aspect of the present invention, there is provided a plasma processing apparatus comprising: a processing container made of a conductive material; an exhaust pump for exhausting the processing container; and a gas pump for introducing a gas into the processing container. A gas supply means, a mounting table provided in the processing chamber for mounting an object to be processed, and a high frequency antenna formed in the shape of a flat spiral coil opposed to each other and disposed outside the processing chamber via an insulating material. In the plasma processing apparatus described above, the mounting table is characterized in that a surface on which the object is mounted is configured to be parallel to a vertical direction.

[0009]

According to an aspect of the present invention, a processing container made of a conductive material, an exhaust pump for exhausting the inside of the processing container,
A gas supply means for introducing a gas into the processing chamber, a mounting table provided in the processing chamber for mounting an object to be processed, and a high-frequency coil formed in a planar spiral coil outside the processing chamber via an insulating material; With the plasma processing apparatus including the antenna and the support mechanism for supporting the object to be processed from below, the processing surface of the object to be processed can be protected from contamination such as fine particles.

According to another aspect of the present invention, a processing container made of a conductive material, an exhaust pump for exhausting the inside of the processing container, a gas supply means for introducing gas into the processing container, It is characterized by comprising a mounting table provided in a container for mounting an object to be processed, and a high-frequency antenna formed in the shape of a planar spiral coil opposed to the processing chamber, with an insulating material interposed therebetween. In plasma processing equipment,
The mounting table is capable of simultaneously processing a plurality of workpieces by a plasma processing apparatus having a surface on which the workpieces are placed parallel to a vertical direction, and a processing surface of the workpieces. Can be protected from contamination such as fine particles.

According to another aspect of the present invention, a first gas component whose amount present in the processing chamber varies relatively greatly during the etching process, for example, reacts with an etching target such as an oxide film during the etching and reacts with the first chamber. And the detected emission intensity remains at a low level. However, when the etching is completed, the emission is not consumed and its abundance increases, so that the detected emission intensity increases. For example, a CF-based processing gas such as CF or CF _2, or conversely, reacts with an etching target such as an oxide film during etching and is actively generated, thus increasing the detected emission intensity. A reaction product such as CO gas, which is no longer produced at the end of the reaction and thus reduces the detected luminescence intensity, The emission intensity ratio with a second gas component whose amount present in the processing chamber does not relatively fluctuate even during the aging process, for example, an inert gas such as argon or nitrogen mixed for plasma stabilization is observed. Since the emission intensity ratio reflects the plasma state in the processing chamber in real time, the RF state applied to the high-frequency antenna is feedback-controlled in accordance with the fluctuation of the emission intensity ratio to maintain the plasma state in the processing chamber optimally. In particular, it is possible to accurately control the end point of the etching. As a method of controlling the high-frequency energy, a method of increasing or decreasing the high-frequency power itself, or a method of adjusting the magnitude, frequency, phase, and amplitude of the high-frequency energy via a matching box or the like can be adopted.

According to another aspect of the present invention, as a result of observing the correlation between the gas pressure in the processing chamber and the etching rate, it is noted that the etching rate is stable at a high etching rate in a predetermined pressure range. In the actual processing, only the pressure fluctuation in the processing chamber is observed, and the actual processing is controlled so as to be within the predetermined pressure range. Thus, stable etching can be performed at a high etching rate.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a plasma processing apparatus constructed according to the present invention will be described below in detail with reference to the accompanying drawings.

The plasma etching apparatus 1 shown in FIG.
The processing container 2 has a cylindrical or rectangular processing container 2 made of a conductive material, for example, aluminum or the like, and a processing object, for example, a semiconductor, is provided at the bottom of the processing container 2 via an insulating plate 3 made of ceramic or the like. A substantially columnar mounting table 4 for mounting the wafer W is accommodated therein. In addition, the top of the processing container substantially opposed to the mounting surface of the mounting table 4 has an insulating material 5,
For example, it is made of quartz glass, ceramic, or the like, and a conductor such as a copper plate, aluminum,
A high-frequency antenna 6 formed of a spiral coil made of stainless steel or the like is arranged. High-frequency energy of, for example, 13.56 MHz can be applied between both terminals (the inner terminal 6a and the outer terminal 6b) of the high-frequency antenna 6 via a matching circuit 8 from a high-frequency power supply 7 for plasma generation. Is configured.

A mounting table 4 for mounting an object to be processed W such as a semiconductor wafer is provided on a susceptor support table 4a formed of aluminum or the like in a columnar shape, and is detachably mounted thereon with bolts 4b and the like. And a susceptor 4c made of aluminum or the like. By thus arranging the susceptor 4c detachably, maintenance or the like can be easily performed.

The susceptor support 4a has cooling means,
For example, a cooling jacket 9 is provided, and a cooling medium such as liquid nitrogen
It is introduced through the refrigerant introduction pipe 11. Further, the liquid nitrogen circulated in the jacket and vaporized by the heat exchange action is discharged from the refrigerant discharge pipe 12 to the outside of the container. With this configuration, for example, the cold heat of -196 ° C. liquid nitrogen is transferred from the cooling jacket 9 to the semiconductor wafer W via the susceptor 4c, and the processing surface can be cooled to a desired temperature.

An electrostatic chuck 12 is formed on the wafer mounting portion on the upper surface of the susceptor 4c, which is formed in a substantially columnar shape, with an area approximately equal to the area of the wafer. The electrostatic chuck 12 is formed, for example, by sandwiching a conductive film 13 such as a copper foil between two polymer polyimide films in an insulating state. The conductive film 13 is connected to a variable DC high-voltage power supply 14 by a lead wire. ing. Therefore, this conductive film 13
By applying a high voltage to the electrostatic chuck 1
The semiconductor wafer W is configured to be able to be suction-held on the upper surface of the semiconductor wafer 2 by Coulomb force.

The susceptor support 4a and the susceptor 4
c, a gas passage 16 through which a heat transfer gas (back cooling gas) such as He is supplied from a gas source 15 to the back surface of the semiconductor wafer W or a joint of each member constituting the susceptor 4c. Are formed. In addition, an annular focus ring 17 is arranged around the upper edge of the susceptor 4c so as to surround the semiconductor wafer W.
The focus ring 17 is made of a high-resistance material that does not attract reactive ions, for example, ceramic or quartz glass, and acts so that reactive ions are effectively incident only on the inner semiconductor wafer W.

Further, a high-frequency power supply 19 is connected to the susceptor 4c via a matching capacitor 18. During processing, a high-frequency power of, for example, 2 MHz is applied to the susceptor 4c so that a bias potential is generated between the susceptor 4c and the plasma. The generated plasma flow can be effectively applied to the processing surface of the object to be processed. The susceptor 4c
A gas supply means 20 made of quartz glass, ceramics, or the like is disposed above. The gas supply means 20 has the shape of a hollow disk having substantially the same area as the mounting surface of the susceptor 4c. A gas supply pipe 21 is connected to the gas supply pipe. A large number of small holes 23 are formed in the lower surface 22 of the gas supply means 20 so that the etching gas is uniformly blown into the lower processing space. In the hollow part of the gas supply means 20,
Projection 25 projecting toward gas supply pipe 21 at the center
Is provided to facilitate mixing of the etching gas supplied from the gas sources 27a and 27b via the mass flow controller 28, and to blow out the gas into the processing chamber at a more uniform flow rate. Is configured. Further, an annular projection 29 acting downward so as to concentrate the gas on the processing surface of the object to be processed is attached downward around the lower surface 22 of the gas supply means 20.

An exhaust pipe 30 is connected to the bottom wall of the processing container 2 so that the atmosphere in the processing container 2 can be exhausted by an exhaust pump (not shown). A gate valve (not shown) is provided, and the semiconductor wafer W is loaded and unloaded through the gate valve.

Further, below the susceptor between the electrostatic chuck 12 and the cooling jacket 9, a heater 32 for temperature adjustment accommodated in a heater fixing base 31 is provided. By adjusting the supplied electric power, the conduction of the cold heat from the cooling jacket 9 is controlled so that the temperature of the surface to be processed of the semiconductor wafer W can be adjusted.

Next, the configuration of the control system of the processing apparatus configured as described above will be described. A transmission window 34 made of a transparent material such as quartz glass is attached to one side wall of the processing chamber 2, and transmits light in the processing chamber to an optical sensor 36 via an optical system 35, and outputs light from the processing chamber. It is configured so that a signal relating to the generated emission spectrum can be sent to the controller 37. A pressure sensor 38 for detecting the pressure in the processing chamber is provided in the processing container 2.
Is attached so that a signal relating to the pressure in the processing chamber can be sent to the controller 37.
The controller 37 sends a control signal based on a feedback signal from these sensors or a preset value to the plasma generating high-frequency power supply 7, the bias high-frequency power supply 15, the refrigerant source 10, the temperature control power supply 33, Cooling gas source 15, processing gas mass flow controller 2
8 to adjust the operating environment of the plasma processing apparatus optimally.

Next, a description will be given of an embodiment in which the control method of the plasma etching apparatus configured according to the present invention is applied to the above-described control system.

First, according to the aspect of the present invention, the emission spectrum of each wavelength detected from the processing chamber through the transmission window 34 when the plasma is generated is processed by the optical system 35 including the spectroscope. A first gas component in which the amount present in the processing chamber fluctuates greatly during the etching process, for example, reacts with an etching target such as an oxide film during the etching, and the consumption in the processing chamber progresses, so that the detected emission intensity is low. Although it is at the level, it is not consumed when the etching is completed, its abundance increases,
Therefore, a signal representing an emission spectrum of a processing gas active species such as a CF-based processing gas such as CF or CF ₂ that increases the detected emission intensity, and conversely, an etching target such as an oxide film during etching. Reaction products, such as CO gas, which are actively generated in response to the reaction, and thus increase the detected luminescence intensity, but stop being generated at the end of the etching, and thus reduce the detected luminescence intensity. Even when the second gas component whose amount present in the processing chamber does not relatively fluctuate, for example, a signal representing an emission spectrum of an inert gas such as argon or nitrogen mixed for plasma stabilization is observed, Signals related to these emission spectra are sent to the controller 37. In the controller 37, an emission intensity ratio regarding the emission spectrum of these two types of gas components is obtained.

In obtaining the emission spectrum, it is possible to detect the peak wavelength of the gas component to be observed through an appropriate interference filter and to perform an arithmetic processing, or the S / N ratio of the emission spectrum is determined. If lower, take the sum average of the emission spectrum in a certain wavelength range,
By performing arithmetic processing based on the sum average value, it is possible to reduce the influence of noise and obtain a highly accurate measurement value.

Since the emission intensity ratio obtained from the emission spectrum thus observed reflects the plasma state in the processing chamber in real time, the high-frequency energy applied to the high-frequency antenna is changed according to the change in the emission intensity ratio. , The plasma state in the processing chamber can be maintained optimally, and in particular, the end point of the etching can be accurately controlled. As a method of controlling the high-frequency energy, a method of increasing or decreasing the high-frequency power itself or a method of adjusting the frequency, phase, and amplitude of the high-frequency energy through a matching box or the like can be adopted as described later. is there.

According to another aspect of the present invention, as a result of observing the correlation between the gas pressure in the processing chamber and the etching rate, as shown in FIG. Since the etching rate is stable at a high value, the etching rate is set within a predetermined range (for example, a
The pressure range (a ₁ or a ₂ ) in the range of (a ₁ to a ₂ ) is determined in advance by an etching process using a dummy wafer, and in actual processing, the pressure fluctuation in the processing chamber is observed by the pressure sensor 38, and the pressure sensor it pressure signal sent to the controller 37 from 38 is not a ₁ as in a _2, sends a control signal from the controller 37 to each device, by performing an etching process, a stable etching at a high etching rate It can be implemented.

Next, the structure of the plasma etching apparatus in the manufacturing process will be described with reference to FIG.
It is to be noted that the same components as those of the plasma etching apparatus described above are denoted by the same reference numerals, and detailed description thereof will be omitted.

As shown in the figure, a load lock chamber 40 adjacent to a side wall of a processing vessel 2 of a high-frequency induction plasma processing apparatus 1 to which the present invention can be applied is opened and closed via a gate valve 39 which can be freely opened and closed. It is connected. The load lock chamber 40 is provided with a transfer device 41, for example, a transfer arm in which an arm made of aluminum is coated with conductive Teflon (registered trademark) to take measures against static electricity. An exhaust pipe 42 is connected to the load lock chamber 40 through an exhaust port provided on the bottom surface, and is configured to be able to be evacuated by a vacuum pump 44 via a vacuum exhaust valve 43.

An adjacent cassette chamber 46 is connected to a side wall of the load lock chamber 40 via a gate valve 45 provided to be freely opened and closed. The cassette chamber 46 is provided with a mounting table 48 on which a cassette 47 is mounted. The cassette 47 is configured to store, for example, 25 semiconductor wafers W as objects to be processed as one lot. Have been. The cassette chamber 46
Is connected to an exhaust pipe 49 through an exhaust port provided on the bottom surface, and the inside of the room can be evacuated by a vacuum pump 44 via a vacuum exhaust valve 50. The other side wall of the cassette chamber 46 is configured to be in contact with the atmosphere via a gate valve 51 provided to be freely opened and closed.

Next, the operation of the plasma processing apparatus 1 configured as described above will be briefly described. First, the gate valve 51 provided between the processing chamber and the atmosphere is opened, and the cassette 47 storing the workpiece W is mounted on the mounting table 48 of the cassette chamber 46 by a transfer robot (not shown). The valve 51 closes. The vacuum exhaust valve 50 connected to the cassette chamber 46 is opened, and the vacuum pump 44 is opened.
As a result, the cassette chamber 46 is placed in a vacuum atmosphere,
It is exhausted to ^-1 Torr.

Next, the gate valve 45 between the load lock chamber 40 and the cassette chamber 46 is opened, and the transfer arm 4 is opened.
The workpiece W is taken out of the cassette 47 placed in the cassette chamber 46 by 1, held and transported to the load lock chamber 40, and the gate valve 45 is closed. The vacuum exhaust valve 4 connected to the load lock chamber 40
3 is opened, and the load lock chamber 40 is evacuated to a vacuum atmosphere, for example, 10 ⁻³ Torr by the vacuum pump 44.

Next, the load lock chamber 40 and the processing vessel 2
The workpiece W is transported to the processing vessel 2 by the transport arm 41 and transferred to a pusher pin (not shown) on the susceptor 4c, and the transport arm 41 is load-locked. After returning to the chamber 40, the gate valve 39 closes. Thereafter, when a high-voltage DC voltage is applied to the electrostatic chuck 12 and the pusher pin is lowered to place the workpiece W on the electrostatic chuck 12, the semiconductor wafer W is mounted and fixed on the susceptor 4c. During this time, the inside of the processing container 2 is opened through a vacuum pump 44 to open a vacuum atmosphere, e.g.
It is evacuated to 0 ^-5 Torr.

Further, cold heat is supplied from the cooling jacket 9 to cool the processing surface of the semiconductor wafer W to a desired temperature. Thereafter, a processing gas such as HF ₃ is introduced into the processing chamber 2 through the gas supply means 20, and an optimum pressure atmosphere is obtained to obtain an optimum etching rate previously obtained by using a dummy wafer according to the present invention. Is reached by the pressure sensor 38, the high-frequency power supply 7 sends the signal to the high-frequency antenna via the matching circuit 8,
By applying a high frequency power of 3.56 MHz, plasma is excited in the processing chamber 2, and a back-cooling gas for heat transfer is supplied to the back surface of the semiconductor wafer W and each joint of the mounting table 4, and further mounted. By applying a bias potential to the mounting table 4, a plasma process such as etching is performed on the workpiece W, for example. During this time, the temperature of the inner wall of the processing chamber is set to 50 ° C. to 100 ° C., preferably 60 ° C.
By heating the mixture to a temperature of from 80 ° C. to 80 ° C., it is possible to prevent the reaction product from adhering to the inner wall.

Further, according to the present invention, the emission spectrum generated from inside the processing chamber 2 at the time of etching is detected by the optical sensor 36 through the transmission window 34. According to the present invention, the abundance due to the plasma reaction is determined. The high-frequency wave applied to the high-frequency antenna is adjusted so that the emission intensity ratio between the first gas component that changes relatively largely and the second gas component whose abundance does not change relatively even by the plasma reaction becomes an optimal value. The frequency, phase, amplitude, etc. of the energy are appropriately controlled. When the detected emission intensity ratio reaches a predetermined value, it is determined that the etching has been completed, the application of the high-frequency energy is stopped, the supply of the processing gas is stopped, and the plasma processing operation ends.

Next, an inert gas such as nitrogen is introduced into the processing container 2 to replace the processing gas and reaction products in the processing container 2, and the gas is evacuated by the vacuum pump 44. After the residual processing gas and reaction products in the processing container 2 are sufficiently exhausted, the processing container 2
A gate valve 39 provided on the side surface of the processing container 2 is opened, the transfer arm 41 moves from the adjacent load lock chamber 40 to the position of the processing target W in the processing container 2, and is lifted from the mounting table 4 by the pusher pin. The processing object W is received, transported to the load lock chamber 40, and the gate valve 39 is closed. In this load lock chamber 40,
If necessary, the object to be processed W is heated to room temperature,
The temperature is raised to 8 ° C., and thereafter, the load lock chamber 40 is carried out to the atmosphere via the cassette chamber 46 to complete a series of operations.

In the embodiment shown in FIG. 1, the inner end 6a and the outer end 6b of the spiral coil as shown in FIG.
Although the high-frequency power supply 7 and the matching circuit 8 are connected between them, the present invention is not limited to such a configuration. For example, as shown in FIG. 5, it is also possible to adopt a configuration in which the high-frequency power supply 7 and the matching circuit 8 are connected only to the outer end 6b of the spiral coil. With such a configuration, it is possible to generate good high-frequency induction plasma in the processing chamber 2 even in a lower-pressure atmosphere.

Next, with reference to FIG. 6 to FIG. 15, embodiments relating to various device configurations for optimally controlling the state of plasma excited in the processing vessel 2 via the high-frequency antenna 6 will be described. In each of the drawings attached to this specification, components having the same functions are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 6 shows another embodiment of the high-frequency antenna 6 attached to the outer wall surface of the insulating material 5. In this embodiment, a part 6c of the high-frequency antenna 6 composed of a spiral coil is double-wound, and its overlapping part 6b
And 6c so that a stronger electromagnetic field can be formed. By partially changing the number of turns of the spiral coil in this way, the density distribution of the plasma excited in the processing chamber 2 can be adjusted.
In the illustrated example, the overlapping portion of the high-frequency antenna 6 is set at the outer peripheral portion. However, the overlapping portion can be set at an arbitrary portion of the high-frequency antenna 6 according to a required plasma density distribution. In the illustrated example, the high-frequency antenna 6
Although the overlapped portion is simply configured as a double winding, it is possible to set an arbitrary number of windings according to a required plasma density distribution.

FIG. 7 shows the mounting table 4 inside the processing vessel 2.
In this embodiment, for example, second electrodes 53a and 53b made of, for example, aluminum are radially arranged at equal intervals so as to surround. These electrodes 53a and 53b are connected to high-frequency power sources 55a and 55b via matching circuits 54a and 54b, respectively.
55b is connected. With this configuration, the mounting table 4
In addition to the high-frequency bias energy applied to the second electrode 53a, the high-frequency bias energy can also be applied to the second electrodes 53a and 53b that radially surround the processing surface of the processing object W from the outer periphery in the radial direction at equal intervals. Therefore, by adjusting the magnitude, amplitude, phase, frequency, and the like of each high-frequency energy, it is possible to optimally control the state of the plasma excited in the processing chamber 2.

FIG. 8 shows an embodiment in which a mesh electrode 56 made of, for example, silicon or aluminum is disposed inside the processing vessel 2 below the gas blowing surface of the gas supply means 20 and above the mounting table 4. It is shown. A variable power supply 57 is connected to the electrode 56, and a distribution of an electric field formed by the action of the high-frequency antenna 6 in the processing container 2 is controlled by flowing an appropriate current through the electrode 56, and the processing container 2 It is possible to excite a plasma having a desired density distribution inside.

Further, in the embodiment shown in FIG. 1, the high-frequency antenna 6 is disposed on the upper surface of the processing container 2 via the insulating material 5 such as quartz glass, but the present invention is not limited to this embodiment. For example, as shown in FIG. 9, a part of the side wall of the processing container 2 is made of an insulating material 5 such as quartz glass or ceramics.
8, and a configuration in which a second high-frequency antenna 59 is attached to the outer wall surface of the insulating material 58 can be adopted. These second high-frequency antennas 59 are preferably arranged in a coil shape, and are configured so that high-frequency energy can be applied from a high-frequency power supply 61 connected via a matching circuit 60. With this configuration, it is possible to excite the plasma also from the side wall portion of the processing container 2. Therefore, by adjusting the high-frequency energy applied to each antenna, a high-density and uniform plasma can be formed with a desired density distribution. 2, it is possible to generate plasma in higher accuracy.

As shown in FIG. 10, a part of the mounting table 4 is made of an insulating material 62 such as quartz glass, a high-frequency antenna 63 is arranged on the lower surface thereof, and a high-frequency power source 68 connected via a matching circuit 67. It is also possible to adopt a configuration in which higher frequency energy is applied to the high frequency antenna 63.
With such a configuration, it is possible to excite the plasma also from the lower surface of the mounting table 4 of the processing container 2. Therefore, by adjusting the high-frequency energy applied to each antenna, a high-density and uniform plasma can be formed in a desired density distribution. Can be generated in the processing container 2, and more accurate plasma processing can be performed.

As shown in FIG. 11, a focus ring arranged around the upper surface of the mounting table 4 is made of an insulating material 69 such as quartz glass or ceramics, and a high frequency antenna 70 is arranged around the focus ring. It is also possible to apply a high-frequency energy from a high-frequency power supply 72 connected to the power supply via a matching circuit 71.
With such a configuration, it is possible to excite the plasma also from the periphery of the mounting table 4 of the processing container 2. Therefore, by adjusting the high-frequency energy applied to each antenna, a high-density and uniform plasma can be formed in a desired density distribution. Can be generated in the processing container 2, and more accurate plasma processing can be performed.

When a relatively large area object such as an LCD is subjected to plasma processing, a plurality of high-frequency antennas 74a, 74b, 74c and 75d are arranged on the upper surface of the processing container 2 as shown in FIG. The matching circuit 75 is attached to the outer wall of the insulating material 5 and is attached to each high-frequency antenna.
It is also possible to adopt a configuration in which high-frequency energy is applied from high-frequency power sources 76a, 76b, 76c, and 76d connected via a, 75b, 75c, and 75d. With such a configuration, it is possible to excite high-density and uniform high-frequency plasma even in a large processing container 2 for processing a target having a relatively large area.

In the above-described embodiment, the configuration is adopted in which the object to be processed W is mounted on the upper surface of the mounting table 4 and the plasma is excited by the high-frequency antenna 6 disposed on the upper surface of the processing container 2. However, the present invention is not limited to such a configuration.
For example, it is also possible to adopt a face-down method as shown in FIG. In this apparatus configuration, each component of the processing apparatus shown in FIG. 1 is arranged almost upside down, and components having the same functions as those shown in FIG. 1 are denoted by the same reference numerals. At the same time, “′” is added to identify the components in FIG. However, in the case of the face-down type apparatus shown in FIG. 13, the support mechanism 76 for supporting the workpiece W from below and the workpiece W are held by the electrostatic chuck 12.
It is preferable to provide a pusher pin mechanism 77 that can be moved up and down for further removal. By adopting such a configuration, the processing surface of the processing target W can be protected from contamination such as fine particles, so that the yield and the throughput can be further improved.

Alternatively, as shown in FIG. 14, a substantially cylindrical processing vessel 2 "is vertically arranged, insulating materials 5" are provided on both sides thereof, and a high-frequency antenna 6 "is provided on the outer wall surface of each insulating material 5". It is also possible to adopt a configuration in which the workpiece W is fixed by suction via electrostatic chucks 12 ″ to both sides of a mounting table 4 ″ that is disposed substantially vertically in the center of the processing container 2 ″. The components of the apparatus shown in Fig. 14 are almost the same as the components of the processing apparatus shown in Fig. 1, and those having the same functions as those of the components shown in Fig. 1 are the same. With reference numerals, FIG.
In order to distinguish from the constituent elements of the above, “” is added. By adopting such a configuration, it is possible to simultaneously process a plurality of workpieces W, and since the surface to be processed of the workpiece W is vertically arranged, the surface to be processed is not contaminated by fine particles and the like. Protected, and the yield and throughput can be further improved.

FIG. 15 shows still another embodiment of the plasma processing apparatus according to the present invention. In this embodiment, the susceptor 4 is completely separated from the wall surface of the processing vessel 2, that is, is mounted on an elevating mechanism 78 which can move up and down, and supplies the susceptor 4 with a cold heat source or a heat transfer gas. Roads or various electric lines are disposed inside the elevating mechanism 78. By adopting such a configuration, the surface to be processed of the susceptor 4 is moved up and down with respect to the high frequency antenna 6 which is a plasma generation source to adjust the surface to be processed into a space having an optimum plasma density distribution. Processing can be performed.

Although the preferred embodiment of the present invention has been described by taking a plasma etching apparatus as an example, the present invention is not limited to such an embodiment, but may be a plasma CVD apparatus, a plasma ashing apparatus, a plasma sputtering apparatus, or the like. The present invention can be applied to other plasma processing apparatuses, and the object to be processed is not limited to a semiconductor wafer but can be applied to an LCD substrate and other objects to be processed.

[0050]

As described above, according to the aspect of the present invention, the processing surface of the object to be processed can be protected from contamination with fine particles and the like, so that the yield and throughput can be further improved. It is possible to do.

According to another aspect of the present invention, it is possible to process a plurality of workpieces W at the same time, and since the processing surfaces of the workpieces W are vertically arranged, the processing surface is reduced. Thus, it is possible to protect the semiconductor device from contamination such as fine particles, and to further improve the yield and the throughput.

According to still another aspect of the present invention, there is provided a first gas component in which the amount present in a processing chamber at the time of an etching process fluctuates relatively greatly, reflecting a plasma state in a processing chamber in real time; Conversely, the emission intensity ratio with the second gas component whose amount present in the processing chamber does not relatively fluctuate even during the etching process is observed. By performing the feedback control of the high-frequency energy applied to the substrate, the plasma state in the processing chamber can be optimally maintained with high accuracy, and in particular, the end point of the etching can be accurately controlled. it can.

According to another aspect of the present invention, the gas pressure in the processing vessel is observed, and the state of the plasma in the processing vessel is feedback-controlled in accordance with the gas pressure. Since the plasma processing of the processing body can be performed, the control system can be simplified.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a plasma processing apparatus to which a control method of a plasma etching apparatus configured according to the present invention can be applied.

FIG. 2 is a graph showing a relationship between an etching rate obtained by a dummy wafer and a gas pressure in a processing container.

FIG. 3 is a configuration diagram of a manufacturing system incorporating the plasma processing apparatus shown in FIG.

FIG. 4 is a plan view showing one embodiment of a high-frequency antenna portion applicable to the processing device of FIG. 1;

FIG. 5 is a plan view showing another embodiment of a high-frequency antenna portion applicable to the processing device of FIG. 1;

FIG. 6 is a schematic cross-sectional view illustrating an embodiment of a processing apparatus to which a high-frequency antenna having another configuration is attached.

FIG. 7 is a schematic sectional view showing an embodiment of a processing apparatus in which a second electrode is mounted in a processing container.

FIG. 8 is a schematic sectional view showing another embodiment of the processing apparatus in which the second electrode is mounted in the processing container.

FIG. 9 is a schematic cross-sectional view showing an embodiment of a processing apparatus in which a second high-frequency antenna is attached to a side wall of a processing container.

FIG. 10 is a schematic sectional view showing an embodiment of a processing apparatus in which a second high-frequency antenna is mounted in a mounting table of a processing container.

FIG. 11 is a schematic sectional view showing an embodiment of a processing apparatus in which a second high-frequency antenna is mounted around a focus ring of a mounting table of a processing container.

FIG. 12 is a schematic cross-sectional view showing an embodiment of a processing apparatus in which a plurality of high-frequency antennas are arranged on an outer wall surface of an insulating material of a processing container.

FIG. 13 is a schematic sectional view showing an embodiment of the face-down processing apparatus.

FIG. 14 is a schematic cross-sectional view showing an embodiment of a processing apparatus in which objects to be processed are arranged vertically.

FIG. 15 is a schematic cross-sectional view illustrating an embodiment of a processing apparatus in which a mounting table is configured separately from a processing container.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plasma processing apparatus 2 Processing container 4 Mounting table 5 Insulating material 6 High frequency antenna 7 High frequency power supply 8 Matching circuit 20 Gas supply means 34 Transmission window 36 Optical sensor 37 Controller 38 Pressure sensor W Semiconductor wafer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4K030 CA04 FA04 GA02 GA12 KA23 KA26 KA30 KA46 LA15 4K057 DA12 DA16 DD01 DE06 DM05 DM06 DM29 DM35 DN01 5F004 AA01 AA14 BA20 BB13 BB17 BB18 BB22 BB25 BB26 BC02 BC05 CA06 CA02 DB03

Claims (13)

[Claims] 1. A processing container made of a conductive material, an exhaust pump for exhausting the inside of the processing container, gas supply means for introducing a gas into the processing container, and provided in the processing container. It is composed of a mounting table on which an object to be processed is mounted, a high-frequency antenna formed into a planar spiral coil outside the processing chamber via an insulating material, and a support mechanism for supporting the object to be processed from below. In the above-mentioned plasma processing apparatus, the mounting table may be configured in a face-down system in which a surface on which the object to be processed is placed faces downward. 2. A processing container made of a conductive material, an exhaust pump for exhausting the inside of the processing container, gas supply means for introducing a gas into the processing container, and a gas supply unit provided in the processing container. A plasma processing apparatus, comprising: a mounting table on which an object to be processed is mounted; and a high-frequency antenna formed in the shape of a planar spiral coil opposed to the processing chamber with an insulating material interposed therebetween. The plasma processing apparatus is characterized in that the mounting table is configured so that a surface on which the object is mounted is parallel to a vertical direction. 3. The plasma processing apparatus according to claim 1, wherein a plurality of said high-frequency antennas are provided. 4. The plasma generator according to claim 1, wherein the processing vessel is grounded. 5. The plasma processing apparatus according to claim 1, wherein high-frequency energy is applied between both terminals of the high-frequency antenna. 6. The plasma processing apparatus according to claim 1, wherein the high-frequency energy is applied only to one end of the high-frequency antenna. 7. The plasma processing apparatus according to claim 1, wherein a high-frequency power source for bias is connected to the mounting table via a capacitor. 8. The susceptor according to claim 1, wherein the mounting table comprises a susceptor support and a susceptor detachably provided on the susceptor support.
The plasma processing apparatus according to any one of the above. 9. The mounting table according to claim 1, wherein an electrostatic chuck is provided on a surface on which the object to be processed is mounted.
The plasma processing apparatus according to claim 1. 10. The mounting table according to claim 1, further comprising at least one of a cooling unit and a temperature control heater.
The plasma processing apparatus according to claim 1. 11. The plasma processing apparatus according to claim 10, further comprising means for supplying a heat transfer gas to a joint between the back surface of the object to be processed and the mounting table. 12. The plasma processing apparatus according to claim 1, wherein the mounting table includes a focus ring surrounding the object to be processed. 13. A processing container made of a conductive material, an exhaust pump for exhausting the inside of the processing container, gas supply means for introducing a gas into the processing container, and provided in the processing container. A plurality of mounting tables for mounting the object to be processed,
A plasma processing apparatus comprising: a plurality of opposing planar spiral coil-shaped high-frequency antennas disposed outside a processing chamber via an insulating material; A plasma processing apparatus, wherein a surface to be placed is configured to be parallel to a vertical direction.