JP3269853B2 - Plasma processing equipment - Google Patents

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 for performing a predetermined process for forming a semiconductor device on a sample such as a wafer by using plasma.

[0002]

2. Description of the Related Art FIG. 6 shows a first conventional high-frequency plasma processing apparatus.

As shown in FIG. 6, a high-frequency signal is applied to one electrode 201 of two electrodes placed opposite to each other in a processing chamber 200 whose inside is set to a vacuum state. , Via the impedance matching unit 211, and the other electrode 202 is grounded. Also,
The reaction gas flows into the processing chamber 200 and the two electrodes 2
By generating a plasma between 01 and 202,
Using the generated plasma, various processes for forming a semiconductor device, such as a fine processing process, a resist stripping process, and a thin film deposition process, are executed.

The high frequency plasma processing apparatus of the first conventional example has an advantage that its structure is simple.
Since the angular frequency ω of the applied high-frequency signal is lower than the generated electron plasma frequency ωpe, the electromagnetic wave of the high-frequency signal cannot propagate in the plasma. Therefore, it is necessary to increase the pressure in the processing chamber 200 set to perform the process, and the ions generated by the plasma move in a more random direction. An undercut occurs in a layer to be formed. Therefore, the high-frequency plasma processing apparatus cannot be applied to anisotropic etching. Further, since the sample comes into contact with the plasma because the sample is placed on the electrode for plasma generation, ions are accelerated to a speed higher than a desired energy by an ion sheath generated on the surface of the sample. Of the sample 3 to be processed
00 is often damaged.

FIG. 7 shows, for example, Japanese Patent Application Laid-Open No. 63-100180.
2 shows a second conventional magnetron high-frequency plasma processing apparatus disclosed in Japanese Patent Application Laid-Open Publication No. H10-209,878. In FIG. 7,
The same components as those in FIG. 6 are denoted by the same reference numerals.

As shown in FIG. 7, similarly to the first conventional example, one of two electrodes placed opposite to each other in a processing chamber 200 whose inside is set to a vacuum state. A high-frequency signal is applied to the electrode 201 from the high-frequency power supply 210 via the impedance matching device 211, and the other electrode 2
02 is grounded. In addition, a reaction gas is caused to flow into the processing chamber 200 to generate plasma between the two electrodes 201 and 202, and a magnetic field B generated by permanent magnets 203 a and 203 b provided below the ground electrode 202 is used. The generated plasma is transferred to the N pole 20 of a permanent magnet.
The density of the plasma is further increased by being confined in an annular shape on the surface of the sample 300 in the magnetic path generated between the 3a and the S pole 203b. And
Various processes are performed using the plasma generated in this manner.

However, in the magnetron high-frequency plasma processing apparatus of the second conventional example, the generated plasma is localized as described above, so that the uniformity of the plasma is reduced. Therefore, for example, when the diameter of the wafer to be processed is large during the etching process, the sample 300
There is a problem that the etching is performed so that the etching depth is different in the radial direction.

FIG. 8 shows a third conventional rotating-field-type high-frequency plasma processing apparatus disclosed in, for example, JP-A-61-86942, and FIG. 9 shows three electromagnets 404 and 404 of the plasma processing apparatus. The arrangement of 405 and 406 is shown. 8 and 9, the same components as those in FIGS. 6 and 7 are denoted by the same reference numerals.

As shown in FIG. 8, similarly to the first and second conventional examples, two electrodes placed opposite to each other in a processing chamber 200 in which the interior is set to a vacuum state are shown. A high-frequency signal is applied to one electrode 201 from a high-frequency power supply 210 via an impedance matching unit 211, and the other electrode 202 is grounded. Further, the reaction gas is supplied to the processing chamber 200.
To generate plasma between the two electrodes 201 and 202. At the same time, rotate the permanent magnet or 3
By applying a phase alternating signal to the solenoid coils 404, 405, 406 arranged as shown in FIG.
A rotating magnetic field B is generated in a direction perpendicular to the direction of the electric field generated between the two electrodes 201 and 202 and rotating in the clockwise direction 410 about the direction of the electric field as an axis. The outer product E of the electric field E and the magnetic field B generated simultaneously at this time
The so-called E × B drift effect (hereinafter referred to as E × B drift effect) occurs in which ions move in a direction of × B under force.
This is called the drift effect. ), The generated plasma is moved on the surface of the sample 300, and as a result, the irradiation amount of the plasma is made uniform, and the degree of processing on the sample 300 is made uniform.

However, in the rotating-field-type high-frequency plasma processing apparatus of the third conventional example, ions in the generated plasma are not perpendicular to the surface of the sample 300 but tilted due to the E × B drift effect. Irradiation is performed in the specified direction, so that an undercut occurs during, for example, an etching process. Therefore, there is a problem that the apparatus cannot be used for fine processing such as anisotropic etching as in the first conventional example.

FIG. 10 shows, for example, Japanese Patent Application Laid-Open No. 62-25643.
No. 3 discloses a fourth conventional example of an electron cyclotron resonance plasma processing apparatus (hereinafter referred to as an ECR plasma processing apparatus). 6 to 9 in FIG.
The same components are denoted by the same reference numerals.

As shown in FIG. 10, a processing chamber 200 in which the inside is set to a vacuum state and a sample 300 is placed at the center thereof.
And a plasma generation chamber 221 whose inside is set to a vacuum state
And a microwave propagation waveguide 222 are connected in cascade, and a magnetic field generation solenoid coil 220 is provided outside the plasma generation chamber 221. The above solenoid coil 2
20, a magnetic field B is generated inside each of the plasma generation chamber 221 and the processing chamber 200 in a direction parallel to the axial direction of each of the chambers 200 and 221.
The electric field of the microwave propagating through 22 is orthogonal. Here, for example, by using a microwave having a frequency of 2.45 GHz and generating a DC magnetic field of 875 Gs (Gauss), the electrons in the plasma generation chamber 221 undergo cyclotron resonance to generate plasma, and the plasma is generated. Various processes are performed using plasma.

However, since it is necessary to generate a relatively high DC magnetic field of 875 Gs, the solenoid coil 220 becomes large, which makes it difficult to reduce the size and weight of the entire device. In addition, since peaks and valleys of the electric field are generated in the plasma generation chamber 221 by the higher-order mode of the microwave, the generated plasma is localized, and the plasma becomes uniform when the diameter of the plasma generation chamber 221 is further increased. Plasma cannot be obtained, and the same problems as in the second conventional example occur.

FIG. 11 shows, for example, US Pat. No. 4,990,2.
29 shows a fifth conventional example of a helicon plasma processing apparatus disclosed in Japanese Patent No. 29; 11, the same components as those in FIGS. 6 to 10 are denoted by the same reference numerals.

As shown in FIG. 11, a cylindrical plasma generating chamber 2 is set in a vacuum state and made of an electrically insulating material.
30 and a cylindrical processing chamber 231 in which the sample 300 is placed at the center thereof are connected in cascade. The pipe 233 is connected. A high-frequency coupling antenna 240 is fixedly provided on an outer peripheral portion of the plasma generation chamber 230, and a magnetic field generator for generating a DC magnetic field B in the axial direction of the plasma generation chamber 230 is provided on the outer peripheral portion of the antenna 240. A solenoid coil 250 is provided. The antenna 240 has a circular upper ring portion 241 and a circular lower ring portion 242.
And a connection element 243 that connects one point of the upper ring part 241 and one point of the lower ring part 242 opposed thereto, and faces the above-mentioned one point of the upper ring part 241 around the center of the upper ring 241. A high-frequency signal output from the high-frequency power supply 210 is applied between the other point and the other point of the lower ring portion 242 opposite to the above-mentioned point with the center of the lower ring 242 as a center. Is entered via
The antenna 240 is excited. At this time, the high-frequency signal combines with and penetrates the plasma generated inside the plasma generation chamber 230, whereby the high-frequency electromagnetic wave
As a helicon wave (Whistler wave), the generated plasma is propagated in the Whistler mode along the magnetic field B in the axial direction in the Whistler mode to attenuate Landau to promote the ionization phenomenon, thereby generating high-density plasma. .

The density n _e [cm ⁻³ ] of the helicon wave generated in the helicon plasma processing apparatus is as follows: (a) The angular frequency ω of the high-frequency signal is sufficiently higher than the ion cyclotron angular frequency ωci, and the electron cyclotron angle A first approximation condition that is sufficiently lower than the frequency ωce;
(B) As is well known, using an approximate expression under the second approximate condition that the diameter of the generated plasma is relatively small,
It can be expressed by the following equation 1.

[0017]

[Number 1] _{n e = (190 · B 0} ) × 10 14 / (r a · f · λ) where, B _0: magnetic flux density of the DC magnetic field [kG], r _a: the radius of the cylindrical plasma The radius of the corresponding plasma generation chamber 230, f: frequency [MHz] of the high frequency signal, λ: wavelength [cm] of the helicon wave.

Therefore, the wavelength λ of the helicon wave to be excited is
Is expressed by Equation 2 from Equation 1 below.

[Number 2] _{λ = (190 · B 0)} / (r a · f · n e × 10 14)

The plasma can be generated by preparing the antenna 240 having the excitation wavelength λ given by the above equation (2). Further, as is apparent from Equation 1, the density of the generated plasma is determined by the magnetic flux density B ₀ of the applied DC magnetic field, the radius r _a of the plasma generation chamber 230,
Since the frequency is determined by the frequency f of the applied high-frequency signal and the wavelength λ of the helicon wave corresponding to the antenna length of the antenna 240, when the overall size of the plasma processing apparatus is determined, the generated plasma Cannot easily be increased in density. In addition, these parameters B
_0, when r _a, f, the value of λ is fixed, there is a problem that can not be changed according to the type of processing to be executed a density of the plasma being the generation.

Further, in the helicon plasma processing apparatus of the fifth conventional example, when the type of the reaction gas is changed to change the type of the process, for example, the density of the generated gas for the process changes. Changes the wavelength of the helicon wave. On the other hand, since the high-frequency coupling antenna 240 is fixedly provided, the degree of coupling between the generated plasma and the high frequency is reduced. As a result, the high-frequency power is not efficiently absorbed by the plasma, and the generated plasma is not absorbed. However, there is a problem that the stability of the resin is reduced.

A first object of the present invention is to solve the above-mentioned problems, and to uniformly and stably generate a high-density plasma on the surface of a sample to be treated as compared with the conventional example. Moreover, it is an object of the present invention to provide a plasma processing apparatus that can be reduced in size and weight.

A second object of the present invention is to solve the above-mentioned problems and to generate a high-density plasma more uniformly and stably on the surface of a sample to be treated as compared with the conventional example. It is another object of the present invention to provide a plasma processing apparatus capable of controlling the density of generated plasma to a predetermined value.

[0023]

According to a first aspect of the present invention, there is provided a plasma processing apparatus for performing a predetermined process on a sample by generating plasma in a plasma processing chamber whose inside is set to a vacuum state. The processing apparatus further includes: a magnetic field generating unit configured to generate a DC magnetic field in a direction toward the sample in the plasma processing chamber; a plurality of rotating electric field generating electrodes provided at a predetermined angle from each other; A rotating electric field rotating in a direction perpendicular to the direction of the DC magnetic field by generating an electric field having the same angular velocity and a predetermined phase difference from each other and having a direction perpendicular to the direction of the DC magnetic field. A group of electric field generating means for generating a plurality of rotating electric fields having a predetermined phase difference with each other, separated from each other by a predetermined distance inside the plasma processing chamber, By providing several groups, and wherein the generating the rotating field to pivot right turn in the direction of the DC magnetic field.

According to a second aspect of the present invention, there is provided the plasma processing apparatus according to the first aspect, further comprising: a measuring means for measuring a density of plasma generated in the plasma processing chamber; At least one of the phase difference between the angular velocity and the plurality of rotating electric fields and the DC magnetic field such that the density of the generated plasma is a predetermined value based on the density of the generated plasma.
And control means for controlling the two.

Further, the plasma processing apparatus according to claim 3 is the plasma processing apparatus according to claim 1 or 2,
Further, another magnetic field generating means for generating a magnetic field inside the plasma processing chamber is provided together with the magnetic field generating means so that the magnetic flux of the generated DC magnetic field is focused and a mirror magnetic field is formed. .

The plasma processing apparatus according to a fourth aspect of the present invention is the plasma processing apparatus according to the first, second or third aspect, further comprising a voltage applying means for applying a predetermined AC voltage to the sample. Features.

[0027]

In the plasma processing apparatus according to the first aspect,
For example, a reaction gas necessary for performing a predetermined process for forming a semiconductor device is introduced into the plasma processing chamber, and the inside of the plasma processing chamber is set to a predetermined vacuum state. Here, the magnetic field generating means includes:
Inside the plasma processing chamber, a DC magnetic field is generated in a direction toward the sample, and a plurality of rotating electric field generating electrodes provided at a predetermined angle from each other are provided. A group of electric field generation that generates a rotating electric field that rotates in a direction perpendicular to the direction of the DC magnetic field by generating an electric field having a phase difference and having a direction perpendicular to the direction of the DC magnetic field. By providing a plurality of means separated from each other by a predetermined distance inside the plasma processing chamber so as to generate a plurality of rotating electric fields having a predetermined phase difference with respect to each other, a rightward direction in the direction of the DC magnetic field is provided. Generate a rotating electric field that rotates around.

Here, a direct current magnetic field generated by the magnetic field generating means causes a collision separation phenomenon due to thermal motion of gas molecules existing in the plasma processing chamber and an ionization phenomenon caused by, for example, irradiation of light or cosmic rays. After the initial ions are generated, the electrons and ions existing in the magnetic field in the plasma processing chamber perform a so-called Larmor motion, which rotates clockwise and counterclockwise around the magnetic field lines, respectively. Further, a rotating electric field generated by the plurality of groups of electric field generating means is applied in a direction perpendicular to the generated magnetic field. Accordingly, the electrons and ions move while rotating in a clockwise direction in a direction perpendicular to both the electric field and the magnetic field due to the ExB drift effect. It rotates at the predetermined angular velocity.

As a result, impact ionization by the α action of electrons and secondary electron emission by the γ action generated by the incidence of ions on the plurality of groups of electric field generating means are repeated, and the plasma state is developed. Here, when the frequency corresponding to the angular velocity of the generated rotating electric field is high,
Even if the γ action does not occur, the ionization phenomenon is promoted. Therefore,
Since the initial electrons move while rotating as described above, the probability that the initial electrons collide with the neutral particles increases, so that the collision ionization phenomenon is likely to occur. As a result, for example, even in a low pressure state of about 10 ⁻³ Torr,
Generation and maintenance of plasma are facilitated.

When a magnetic field is present, the electromagnetic wave caused by the rotating electric field can propagate through the plasma without being blocked at the plasma surface. In other words, the electromagnetic wave penetrates into the plasma, propagates in a direction parallel to the magnetic field, and attenuates Landau while giving energy to electrons. The helicon wave described in the section of the related art is basically a right-handed polarized electromagnetic wave that turns an electromagnetic field clockwise with respect to the direction of a magnetic field. Therefore, in the present invention, a rotating electric field that rotates clockwise in the direction of the DC magnetic field, that is, in the direction toward the sample, is generated, so that the helicon wave is effectively excited in the generated plasma. Can be. Therefore, the energy of the electrons in the plasma is given by the Landau damping of the wave of the helicon wave, whereby a high-density plasma can be generated. That is, the electrons in the plasma absorb energy by the electric field of the electromagnetic wave of the helicon wave that has propagated in the plasma, and further contribute to the ionization phenomenon. Can generate plasma with
Further, the density of plasma can be increased.

As described above, the plasma generated by the magnetic field and the rotating electric field is transported in the direction of the magnetic field lines of the magnetic field, and then incident in a direction substantially perpendicular to the surface of the sample.

In the apparatus according to the present invention, since the rotating electric field is generated as described above, the electrons and ions in the plasma move in the direction of the outer product E × B, and the moving direction due to the E × B drift effect changes. Since the plasma is rotated at the predetermined angular velocity, it is possible to prevent the plasma from being biased, whereby the surface of the sample can be uniformly irradiated with the plasma.

Further, in the plasma processing apparatus according to the second aspect, after the measuring means measures the density of the plasma generated in the plasma processing chamber, the control means:
Based on the density of the plasma measured by the measuring means, at least one of the phase difference between the angular velocity and the plurality of rotating electric fields and the DC magnetic field such that the density of the generated plasma becomes a predetermined value. Control one. Therefore, the density of the plasma can be controlled to a predetermined value by controlling the coupling with the wave of the helicon wave in the generated plasma to be in an optimum state.

Further, in the plasma processing apparatus according to the third aspect, the another magnetic field generating means may include the plasma generating means together with the magnetic field generating means so that a magnetic flux of the generated DC magnetic field is focused to form a mirror magnetic field. A magnetic field is generated inside the processing chamber. As a result, a so-called mirror magnetic field can be generated, the incident angle of the plasma incident on the surface of the sample becomes substantially vertical throughout the entire sample, and the plasma processing apparatus can be applied to anisotropic etching.

Still further, in the plasma processing apparatus according to the fourth aspect, the voltage applying means applies a predetermined AC voltage to the sample. At this time, by changing the applied AC voltage, the amount of ions in the plasma incident on the sample can be controlled. Thereby, for example, when a semiconductor device is formed, more precise processing can be performed.

[0036]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of a plasma processing apparatus according to an embodiment of the present invention, FIG. 2 is a longitudinal sectional view taken along line AA ′ of FIG. 1, and FIG. FIG. 3 is a cross-sectional view of the processing apparatus taken along line BB ′. 1 to 3, the same components as those in FIGS. 8 to 13 are denoted by the same reference numerals.

The plasma processing apparatus according to the present embodiment has four rotating electric fields arranged above the outer peripheral portion of a cylindrical plasma generating chamber 10 whose interior is set to a vacuum state so as to be separated from each other by a right angle. Generation electrodes ER11 to ER14
And a first electrode group ER1 composed of the first and second electrodes ER1 to ER1.
When applied to R14, the first electric field rotates in a direction perpendicular to the axial direction of the cylinder of the plasma generation chamber 10 (hereinafter, referred to as the Z-axis direction) and rotates clockwise about the axis of the cylinder. E1 is generated, and four rotating electric field generators are arranged below the first electrode group ER1 at a lower part of the outer peripheral portion of the plasma generation chamber 10 so as to be separated from each other by a right angle. A second electrode group ER2 including the electrodes ER21 to ER24 is provided, and a high-frequency signal having a phase shifted from the high-frequency signal applied to the first electrode group ER1 by a predetermined phase difference φ and having a phase different by π / 2 from each other. Is applied to each of the electrodes ER21 to ER24 to rotate the second electrode in a direction perpendicular to the Z-axis direction of the plasma generation chamber 10 and clockwise around the axis O of the cylinder. Field E2, ie two first and second electric fields E1, rotating with a phase difference from each other
E2 is generated to generate a rotating electric field E rotating clockwise so as to effectively excite the helicon wave generated in the plasma generation chamber 10, and further, the first and second electrode groups E
R1 and ER2 are provided with four solenoid coils 21 to 24 for generating a magnetic field on the outer periphery thereof.
To 24, a predetermined DC voltage is applied to generate a magnetic field in a direction parallel to the Z-axis direction and toward the sample 300, thereby generating a plasma. An electromagnetic wave of a high-frequency signal for generating an electric field propagates, and the plasma is irradiated on the upper surface of the sample 300 placed in the plasma processing chamber 11 following the generation chamber 10.

In the plasma processing apparatus of the present embodiment, the transmitting horn antenna AN1 is radiated at a position in the Z-axis direction between the solenoid coils 22 and 23 on the outer peripheral portion of the plasma generating chamber 10. A transmitting horn antenna AN1 and a receiving horn antenna AN2 are provided so that a microwave signal passes through the central axis of the plasma generation chamber 10 and faces each other.
Calculating the density of the generated plasma using the method of the microwave interferometer based on the microwave signal received by the two and effectively exciting the helicon wave based on the calculated density of the plasma; It is characterized in that the phase difference φ is changed.

As shown in FIGS. 1 to 3, for example, an electrically insulating material such as alumina or quartz glass is connected to the bottom of a cylindrical plasma generating chamber 10 so as to allow air to flow therethrough. A plasma processing chamber 11 made of an electrically insulating material and having a larger diameter than the plasma generating chamber 10 is connected. A sample support 30 made of an electrically insulating material is fixed to a bottom surface of the plasma processing chamber 11,
A bias voltage application electrode 31 is formed on the sample support table 30, and a sample 300, for example, a wafer of a semiconductor device, is mounted on the electrode 31 so that the surface thereof is perpendicular to the Z axis. Here, the high-frequency bias signal generator 32 applies a bias AC signal such as a high-frequency signal to the electrode 31 via the capacitor 32 and controls the voltage of the signal by applying a high-frequency signal having a predetermined high-frequency voltage to the electrode 31. Ion in the generated plasma is sample 3
The amount incident on 00 is controlled. Thereby, for example, when a semiconductor device is formed, more precise processing can be performed.

Further, on the upper surface of the plasma generation chamber 10,
Gas cylinders 13a and 13b for storing a predetermined reaction gas are connected via a reaction gas transport pipe 11a, a valve 15, and variable leaks 14a and 14b, respectively, while an exhaust pipe 11b is provided on the bottom surface of the plasma generation chamber 10.
And a vacuum adjusting valve 16 via a pressure adjusting valve 16.

On the upper side of the outer peripheral portion of the plasma generation chamber 10 in FIGS. 1 and 2, four electrodes ER11 to ER14 each having a curved shape so as to be parallel to the outer peripheral portion of the plasma generation chamber 10 are provided. Electrode group ER1 composed of
As shown in FIG. 3, the electrodes ER11 to ER14 are separated from each other by a right angle about the axis O of the cylinder of the plasma generation chamber 10 as shown in FIG. ER12, ER13, ER
14 are provided in this order. In addition, the upper and lower sides of the outer peripheral portion of the plasma generation chamber 10 in FIGS. 1 and 2 and each electrode of the second electrode group ER2 from a middle position in the Z-axis direction of each electrode of the first electrode group ER1. Of four electrodes ER21 to ER24 each having a curved shape so as to be parallel along the outer peripheral portion of the plasma generation chamber 10 at an intermediate position in the Z-axis direction.
The second electrode group ER2 composed of
R24 is the same as the first electrode group ER2 in the plasma generation chamber 1
Electrodes ER21, ER22, ER23, and ER24 are provided in this order at right angles to each other with the axis of the cylinder 0 as the center O and at a right angle when viewed from above the plasma generation chamber 10.

As described above, the electrodes ER11 to ER11
The shape of R14, ER21 to ER24 is changed to plasma generation chamber 1
0, the first and second electric fields E1, E2 are more uniform inside the plasma generation chamber 10, and the rotating electric fields E1, E2 are concentrated at one location. Can be prevented.

Further, as shown in FIGS. 1 and 2, the solenoid coil 2
At a position in the Z-axis direction between 2 and 23, the transmitting horn antenna AN1 and the receiving horn antenna AN1 pass through the central axis of the plasma generation chamber 10 and face each other so that the microwave signal radiated from the transmitting horn antenna AN1 faces. Horn Antenna AN
2 are provided. Further, the magnetic field generating solenoid coils 21 to 24 are provided on the outer peripheral portions of the first electrode group ER1 and the second electrode group ER2 by a predetermined distance from each of the electrode groups ER1 and ER2 in the Z-axis direction. Provided. Each of the electrode groups ER1, ER2 is connected to the corresponding one of the solenoid coils 21 to 24.
By applying a predetermined DC voltage necessary to generate a DC magnetic field having a magnetic flux density greater than the magnetic flux density of the magnetic field at which the electron cyclotron frequency is equal to the frequency of the high-frequency signal applied in the Z-axis direction, the plasma is generated. In the chamber 10 and the plasma processing chamber 11, a DC magnetic field B is generated in a direction parallel to the Z axis and toward the sample 300.

Further, each electrode ER of the first electrode group ER1
High frequency signals V11 to V14 represented by the following formulas having the same angular frequency ω and a phase different from each other by π / 2 are applied to the electrodes ER11 to ER11 of the first electrode group ER1, respectively. ER14 and the same angular frequency ω and π
High-frequency signals V21 to V24 represented by the following equations and having phases different by / 2 are applied to the respective electrodes ER21 to ER24 of the second electrode group ER2.

[0046]

## EQU3 ## V11 = V · sin (ωt)

## EQU4 ## V12 = V · sin (ωt + π / 2)

V13 = V · sin (ωt + π)

V14 = V · sin (ωt + 3π / 2)

V21 = Vsin (ωt + φ)

V22 = V · sin (ωt + π / 2 + φ)

V23 = V · sin (ωt + π + φ)

V24 = V · sin (ωt + 3π / 2 + φ)

Here, the phase difference φ is preferably set to a phase shift amount represented by the following equation 11 in the initial state.

Where L is the distance [cm] between the center of the first electrode group ER1 in the Z-axis direction and that of the second electrode group ER2, and λ is represented by the following equation (2). Of the helicon wave [cm].

FIG. 5 shows an electrode application signal generation circuit of the plasma processing apparatus of FIG. As shown in FIG. 5, the high-frequency signal generator 50 generates a sine-wave reference high-frequency signal V0 having an angular frequency ω and outputs it to the electrode ER1 via the PLL circuit 51a, the amplifier 52a, and the impedance matching device 53a. Here, the PLL circuit 51a includes a phase detector 71, a low-pass filter (LPF) 72, and a voltage-controlled oscillator 73. The high-frequency signal V11 applied to the electrode ER11 is fed back to the phase detector 71, and the PLL circuit 51a 51a controls the phase difference between the reference high-frequency signal V0 and the high-frequency signal V11 to be zero.

The PLL circuits 51b, 51c, 51 to be described later
d, 51e, 51f, 51g, and 51h are also PLL circuits 51.
It is configured in the same way as a and performs the same operation.

The reference high-frequency signal V0 has the phase π.
The voltage is applied to the electrode ER12 and the PLL circuit 51b via the phase shifter 60b for shifting the phase by / 2, the PLL circuit 51b, the amplifier 52b, and the impedance matching device 53b. At this time, the high-frequency signal V12 is applied to the electrode ER12. Further, the reference high-frequency signal V0 is applied to the electrode ER13 and the PLL circuit 51c via the phase shifter 60c for shifting the phase by π, the PLL circuit 51c, the amplifier 52c, and the impedance matching device 53c.
Is applied with a high-frequency signal V13. Further, the reference high-frequency signal V0 is applied to the electrodes ER14 and PLL via a phase shifter 60d for shifting the phase by 3π / 2, a PLL circuit 51d, an amplifier 52d, and an impedance matching unit 53d.
The high frequency signal V14 is applied to the circuit 51d, and at this time, the high frequency signal V14 is applied to the electrode ER14.

Further, the reference high-frequency signal V0 is input to a variable phase shifter 61 whose phase shift amount φ is controlled by a controller 100 described later in detail. After the phase is shifted by the phase φ, the signal is output as the phase-shift reference high-frequency signal V20.

The phase-shift reference high-frequency signal V20 is a PLL
Circuit 51e, amplifier 52e, impedance matching unit 53
e, and is applied to the electrode ER21 and the PLL circuit 51e. At this time, the high-frequency signal V21 is applied to the electrode ER21. The phase-shift reference high-frequency signal V20 is phase-shifted by a phase shifter 60f and a PLL circuit 51 for shifting the phase by π / 2.
The high frequency signal V22 is applied to the electrode ER22 and the PLL circuit 51f through the amplifier f, the amplifier 52f, and the impedance matching unit 53f. Further, the phase-shift reference high-frequency signal V20 has a phase π
Is applied to the electrode ER23 and the PLL circuit 51g via the phase shifter 60g, the PLL circuit 51g, the amplifier 52g, and the impedance matching device 53g for shifting only the phase.
The high frequency signal V23 is applied to the electrode ER23. Further, the phase-shift reference high-frequency signal V20 has a phase of 3π / 2.
Is applied to the electrode ER24 and the PLL circuit 51h via a phase shifter 60h, a PLL circuit 51h, an amplifier 52h, and an impedance matching unit 53h, which shifts only the phase.
The high-frequency signal V24 is applied to the electrode ER24.

When the high-frequency signals V11 to V14 are applied to the electrodes ER11 to ER14, respectively, the angular frequency ω of the high-frequency signal is in a direction perpendicular to the Z-axis direction and clockwise about the axis of the cylinder O. Is generated at the upper part of the plasma generation chamber 10 while the high-frequency signals V21 to V24 are applied to the electrodes ER21 to ER24, respectively, in a direction perpendicular to the Z-axis direction. A second electric field E2 that rotates with the angular velocity of the angular frequency ω of the high-frequency signal clockwise about the axis O of the cylinder and shifted by a predetermined phase difference φ from the first electric field E1 generates plasma. Generated in the lower part of the chamber 10. As a result, a rotating electric field E that rotates clockwise for effectively exciting the helicon wave generated in the plasma generation chamber 10 is generated.

FIG. 4 is a block diagram showing a microwave interferometer section and a control section of the plasma processing apparatus of FIG. In this embodiment, the density of the plasma generated by using the method of the microwave interferometer is calculated, and the helicon wave is effectively excited in synchronization with the rotating electric field E based on the calculated density of the plasma. Thus, the phase difference φ is changed.

Referring to FIG. 4, a microwave signal generator 80
Generates a microwave signal having a frequency sufficiently higher than the frequency of the high-frequency signal, for example, 34 GHz,
The microwave signal is supplied to the variable attenuator 81 and the main transmission line 8.
The signal is output to the transmission horn antenna AN1 via the main transmission line 82a of the directional coupler 82 having the transmission transmission line 2a and the auxiliary transmission line 82b electromagnetically coupled thereto. Here, the sub transmission line 82b of the directional coupler 82 is connected to the main transmission line 82a.
Of the microwave signal transmitted to the main transmission line 87a and the sub transmission line 87b via the variable attenuator 84, the variable phase shifter 85, and the variable attenuator 86. Transmission line 87 of the directional coupler 87 provided with
b. The transmitting horn antenna AN1 passes the input microwave signal through the plasma generated in the plasma generating chamber 10 as indicated by an arrow MA, and receives the horn antenna AN2 provided opposite to the horn antenna AN1. Radiate. Horn antenna for receiving AN
1 outputs the received microwave signal to the main transmission line 87a of the directional coupler 87 via the variable attenuator 83.
Further, the directional coupler 87 detects a part of the microwave signal input to the sub transmission line 87b, and converts the detected part of the microwave signal and the microwave signal input to the main transmission line 87a. Mixing causes interference between the electromagnetic waves of each signal, and the mixed microwave signal is
Output to Further, the diode detector 88 detects the inputted microwave signal and outputs the detected current to the current detector 89.
And in response to this, the current detector 89 generates an analog voltage signal proportional to the detected current value, and through an analog / digital converter (A / D converter) 90 as a digital voltage signal. Output to the controller 100.

When plasma is not generated in the plasma generation chamber 10, the microwave signal input to the main transmission line 87a and the microwave signal input to the sub transmission line 87b are converted into a directional coupler 87. Main transmission line 8
At the output end of 7a, a variable phase shifter 8
5, the phase shift amount is adjusted. Next, when the plasma is generated in the plasma generation chamber 10, the directional coupler 87 mixes the microwave signal that has passed through the plasma with the microwave signal that is a reference signal that does not pass through the plasma. Interference is generated between two electromagnetic waves of the microwave signal, and the amount of the DC component after mixing is detected as a phase difference Δθ. As is well known, the phase difference Δθ [rad] is proportional to a value obtained by integrating the density of the plasma included in the microwave path. Therefore, the density n _e of the generated plasma [cm ^-3] is that the refractive index of the plasma in the range of density n _e of the plasma is sufficiently smaller than the density n _ce of the electron cyclotron is proportional to the density of electronic Under the approximate condition, it can be expressed by the following equation 12, as is well known.

[0057]

Equation 12] _{n e = 118 · ωm · Δθ} / 2r a where, .omega.m: angular frequency of the microwave signal generated by the microwave signal generator 80 [Hz], 2r _a: plasma microwave signal passes , That is, the diameter [cm] of the cylinder of the plasma generation chamber 10. Further, the frequency of the microwave signal generated by the microwave signal generator 80 is preferably set to a sufficiently high frequency of at least three times the cutoff frequency corresponding to the electron density of the plasma to be measured. Note that the electron density obtained from Equation 12 is the amount of the average value averaged over time and space.

From the above equation (12), as the phase difference Δθ increases, the plasma density _ne increases. If the density n _e of the plasma is greater than the predetermined set value n _e s, it may be the number 1 long wavelength λ of helicon waves from, therefore, the density n _e of the plasma by reducing the above retardation Δθ it can be brought close to the set value n _e s. Using this principle, the controller 100 performs control processing as follows.

The controller 100 calculates the phase difference Δθ using a predetermined conversion equation based on the voltage of the input digital voltage signal, and then calculates the plasma density n based on the calculated phase difference Δθ using Equation 12. Calculate _e . Meanwhile, the operator of the plasma density n _e s to be set is input to the controller 100 using the keyboard 101. Then, the controller 100 is greater than the calculated plasma density n _e is the plasma density n _e s should be set to reduce the phase difference φ of the variable phase shifter 61, while the calculated plasma density n density n _e s of the plasma _e is to be set
If it is smaller, the variable phase shifter 61 is controlled so that the phase difference φ of the variable phase shifter 61 is increased. by this,
The density of the plasma generated in the plasma generation chamber 10 is
Control can be performed to set the density n _{es of} the plasma input by the operator.

In the plasma processing apparatus configured as described above, for example, a reaction gas required for performing a predetermined process for forming a semiconductor device is supplied from the gas cylinders 13a and 13b through the variable leaks 14a and 14b. Is mixed and generated at a predetermined mixing ratio, and the generated mixed gas 500 flows into the plasma generation chamber 10 and the plasma processing chamber 11 via the valve 15 and the reaction gas transport pipe 11a. On the other hand, pump 17
Is driven, the gas 510 in the plasma generation chamber 10 and the plasma processing chamber 11 is exhausted to the pump 17 via the exhaust pipe 12 and the pressure adjustment valve 16, and by using the pressure adjustment valve 16, The inside of the plasma processing chamber 11 is set to a predetermined vacuum state.
In the present embodiment, it is preferably set to a state of 10 ⁻³ Torr or less.

The generated rotating electric fields E1, E2
After the initial electrons and initial ions are generated by the collision separation phenomenon due to the thermal motion of the gas molecules existing between the electrodes and the ionization phenomenon caused by the irradiation of light or cosmic rays, the rotating electric field E in the plasma generation chamber 10 is generated. The electrons and ions existing in the device oscillate at angular frequencies ω in the directions of the electric fields E1 and E2, and impact ionization due to α action and secondary electron emission due to γ action due to ion incidence on the electrode are repeated. Evolves into a plasma state. Here, when the frequency of the applied high-frequency signal is high, since the polarity is inverted before the electrons reach the electrodes, the ionization phenomenon is promoted even if the γ action does not occur. Even if it is placed outside the generation chamber 10, or the electrode group ER1,
Even if ER2 is covered with an electrical insulator, a discharge phenomenon occurs. Preferably, by placing the electrode groups ER1 and ER2 outside the plasma generation chamber 10 as in the present embodiment, plasma containing no constituent material of each electrode of the electrode groups ER1 and ER2, that is, plasma having no impurities at all. Can occur.

As shown in FIGS. 1 to 3, a DC magnetic field B is generated in the Z-axis direction, which is parallel to the axial direction of the cylinder of the plasma generation chamber 10, so that electrons and ions respectively move around the magnetic force lines rightward. A helical motion called a so-called Larmor motion is performed in the clockwise and counterclockwise directions. Further, as described above, since the rotating electric field E perpendicular to the magnetic field B having a direction perpendicular to the Z-axis direction is generated, the initial electrons are generated by the rotating electric field E and the magnetic field by the E × B drift effect. B moves while rotating in a direction perpendicular to both directions, and further rotates at an angular velocity corresponding to the frequency of the applied high-frequency signal. As a result, the probability that the initial electrons collide with the neutral particles increases, so that the impact ionization phenomenon is likely to occur.
As a result, generation and maintenance of plasma are facilitated even in a low pressure state of, for example, about 10 ⁻³ Torr.

For example, when a rotating electric field E is applied to the plasma without any DC magnetic field B, the angular frequency ω of rotation of the rotating electric field E is changed to the electron plasma frequency ωpe (≒ 10
^{At 4} ( _ne ) ^1/2 Hz (where _ne is the electron density) or less, the rotating electric field E is shielded by the collective motion of electrons on the surface of the plasma, and the rotating electric field E becomes It cannot penetrate into the plasma. However,
When a DC magnetic field B is applied to the plasma by the solenoid coils 21 to 24, the movement of the electrons is restricted.
Electromagnetic waves with low frequencies can also propagate in plasma. For example, when a magnetic field B of 4.9 Gs or more is applied, the angular frequency ω of the applied high frequency signal is sufficiently lower than the electron cyclotron angular frequency ωce and sufficiently higher than the ion cyclotron angular frequency ωci. When the first approximation condition described above is satisfied, for example, when the frequency of the angular frequency ω is 13.56 MHz, the electromagnetic wave of the high-frequency signal can propagate in the plasma.
In other words, when a magnetic field B of 4.9 Gs or more is applied in the Z-axis direction, the applied high frequency signal electromagnetic wave having a frequency of 13.56 MHz penetrates the plasma and propagates in a direction parallel to the DC magnetic field B. Then, Landau damps while giving energy to the electrons. Therefore, the electrons in the plasma absorb energy by the electric field of the electromagnetic wave propagating in the plasma, and further contribute to the ionization phenomenon. Plasma can be generated in a gas pressure state, and the density of the plasma can be increased.

In the present embodiment, the helicon wave is effectively excited by using the rotating electric field E that turns clockwise with respect to the direction of the Z axis toward the sample 300, that is, the direction of the DC magnetic field B. That is, the helicon wave is basically a right-handed polarized electromagnetic wave that turns the electromagnetic field clockwise with respect to the direction of the magnetic field. To effectively excite this helicon wave,
Using the first rotating electric field E1 and the second rotating electric field delayed from the first rotating electric field E2 by a phase difference φ corresponding to the wavelength λ of the helicon wave, a rotating electric field E rotating clockwise is generated. Let it. Actually, since there is a boundary of a discharge tube which is an outer peripheral wall of the plasma generation chamber 10, a hybrid wave having an electric field component in a direction along the DC magnetic field B does not propagate as a pure transverse wave (electromagnetic wave). Become. Therefore,
The Landau damping of the wave of the helicon wave gives energy to the electrons in the plasma, whereby a high-density plasma can be generated.

As described above, the plasma generated by the DC magnetic field B and the rotating electric field E rotating clockwise is transported in the direction of the line of magnetic force of the DC magnetic field B, that is, in the Z-axis direction. And is irradiated in a direction substantially perpendicular to the light.

In this embodiment, since the rotating electric field E is generated as described above, the electrons and ions in the plasma move in the direction of the outer product E × B, and the moving direction rotates at the angular velocity ω. Therefore, it is possible to prevent the plasma from being biased, whereby there is an advantage that the surface of the sample 300 can be uniformly irradiated with the plasma.

In this embodiment, the plasma is transported by the generated magnetic field B without confining the plasma as in the second conventional magnetron plasma processing apparatus. Can be irradiated.

In this embodiment, since the angle between the direction of the electric field E generated by the ion sheath near the upper surface of the sample 300 and the DC magnetic field B is almost 0 degrees, the phenomenon of the E × B drift effect is reduced. Sample 3
Since it is perpendicular to the surface of the sample 300, the angles of the ions and electrons incident on the sample 300 with respect to the sample 300 are 90 degrees. Therefore, for example, when the etching process is performed, the etching process can be performed more accurately in the direction perpendicular to the surface of the sample 300 than the rotating magnetic field type high frequency plasma processing apparatus of the third conventional example. There is an advantage that the apparatus of the present embodiment can be applied to anisotropic etching processing with less undercut.

In the fourth conventional ECR plasma processing apparatus, for example, the frequency of a high-frequency signal is 2.45 GHz.
875 Gs of magnetic field B to generate plasma when
However, in the apparatus of this embodiment, it is sufficient to generate a magnetic field B of, for example, about 5 Gs or less, and only by generating a magnetic field B smaller by two orders of magnitude than in the fourth conventional example. For this reason, the size of the magnetic field generating solenoid coils 21 to 24 can be significantly reduced, and the plasma processing apparatus can be reduced in size and weight.

In general, the diameter of the plasma generation chamber 10 is about several meters or less, and the frequency of the high-frequency signal applied in this embodiment is 13.56 MHz. It is much larger than 10 diameters. Therefore, unlike the ECR plasma processing apparatus of the fourth conventional example, localization due to valleys and peaks of the electric field in the higher-order mode does not occur. Therefore, more uniform plasma can be generated in a larger area than in the fourth conventional example.

Further, unlike the fifth conventional example, since the antenna 240 is not used, the generation of plasma does not become unstable due to a decrease in the degree of coupling between the electromagnetic field of the high-frequency signal and the plasma. Further, since there is no need to provide the antenna 240 for propagating the helicon wave, the device can be made smaller than the fifth conventional example.

Further, in this embodiment, the density of the plasma generated in the plasma generation chamber 10 is measured by the microwave interferometer shown in FIG. 4, and the level of the high-frequency signal is determined based on the measured density of the plasma. By controlling the phase difference φ, the density of the plasma can be controlled to a predetermined value by controlling the coupling with the wave of the helicon wave in the plasma to an optimum state.

[0073] In the above embodiments, based on the measured plasma density n _e, but by controlling the density of the plasma by controlling the phase difference φ of the high-frequency signal,
The present invention is not limited to this, as the number 1 is clear, based on the measured plasma density n _e, the phase difference phi,
The angular velocity of the rotation frequency f that is, the rotational electric field E1, E2 of the high-frequency signal omega, and may control the plasma density n _e by varying at least one of the magnetic flux density of the DC magnetic field B applied.

In the above embodiment, four magnetic field generating solenoid coils 21 to 24 are used. However, the present invention is not limited to this, and one or more magnetic field generating solenoid coils may be provided. As shown in FIG. 12, another solenoid coil 25 is provided on the outer peripheral portion of the DC magnetic field B generated below the plasma processing chamber 11, and the solenoid coil 25 is the same as the solenoid coils 21 to 24. Are applied with the same current value.
Thus, the so-called mirror magnetic field is generated by converging the magnetic flux diverged only by the solenoid coils 21 to 24 by the solenoid coil 25. Thereby, the incident angle of the plasma incident on the upper surface of the sample 300 becomes vertical over substantially the whole of the sample 300, and the plasma processing apparatus can be applied to the anisotropic etching process.

Further, it may be set so that a mirror magnetic field is formed by controlling a current value applied to the solenoid coils 21 to 24.

In the above embodiment, a high-frequency signal is used. However, the present invention is not limited to this, and an AC signal including a low-frequency signal may be used.

In the above embodiment, the electrode 31 and the bias signal generator 33 are provided. However, the present invention is not limited to this, and the electrode 31 and the bias signal generator 33 may not be provided.

In the above embodiment, the density of the generated plasma is detected by using the method of the microwave interferometer. However, the present invention is not limited to this, and the electrostatic probe is inserted into the plasma generation chamber 10. A known electrostatic probe method for measuring the density of plasma generated by the above method may be used.

In the above embodiment, the first and second electrode groups ER1 and ER2 each including four electrodes ER11 to ER14 and ER21 to ER24 are used.
The present invention is not limited to this, and a plurality of n sets of electrode groups ERRp (p = 1, 2,..., N) each including three or more natural number m electrodes ERk (k = 1, 2,..., M) , The high-frequency signal V (p,
By applying k), a rotating electric field E turning clockwise for effectively exciting the helicon wave may be generated.

[0080]

V (p, k) = V · sin {ωt + (k−1) 2π / k + φp}, p = 1, 2,..., N; k = 1, 2,. φp is preferably represented by the following equation (14).

Φp = 2πL _p-1 / λ where L _p-1 is the _p-th power from the first electrode group ERR1.
And the distance to the electrode group ERRp is L ₀ = 0.

Further, in order to generate the rotating electric fields E1 and E2, the electrodes may be rotated around the Z-axis at the outer peripheral portion of the plasma generating chamber 10 to generate the rotating electric fields.

In the above embodiment, the first and second electrode groups ER1 and ER2 are provided on the outer peripheral portion of the plasma generation chamber 10. However, the present invention is not limited to this.
It may be provided inside. Further, the magnetic field generating solenoid coils 21 to 24 may be provided in the plasma generation chamber 10.
Further, in the present embodiment, the plasma generation chamber 10 and the plasma processing chamber 11 are separated, but the present invention is not limited to this, and each of the chambers 10 and 11 may be constituted by one chamber.

[0083]

As described above in detail, according to the present invention, there is provided a plasma processing apparatus for performing a predetermined process on a sample by generating plasma in a plasma processing chamber whose inside is set to a vacuum state. Inside the processing chamber, a magnetic field generating means for generating a DC magnetic field in a direction toward the sample is provided, and a plurality of rotating electric field generating electrodes provided at a predetermined angle from each other are provided. A group of groups generating a rotating electric field that rotates in a direction perpendicular to the direction of the DC magnetic field by generating an electric field having a predetermined phase difference and having a direction perpendicular to the direction of the DC magnetic field. By providing a plurality of groups of electric field generating means separated from each other by a predetermined distance inside the plasma processing chamber so as to generate a plurality of rotating electric fields having a predetermined phase difference from each other, It generates a rotating field to pivot right turn in the direction of the DC magnetic field.

Therefore, the helicon wave is effectively excited by the rotating electric field that rotates clockwise in the direction of the DC magnetic field generated by the plurality of groups of electric field generating means, and the helicon wave is excited by the magnetic field. Since the plasma is propagated inside the plasma, the degree of vacuum can be increased as compared with the first conventional example, that is, the density of the plasma can be significantly increased while the gas pressure in the plasma processing chamber is reduced. Further, the plasma is not confined as in the second conventional example, and the plurality of rotating electric fields are generated, so that the electrons and ions in the plasma are directed in the direction of the outer product E × B of the electric field E and the magnetic field B. , And the moving direction rotates at the above-mentioned predetermined angular velocity, so that it is possible to prevent the plasma from being biased. Further, since the generated plasma is transported by the magnetic field, the surface of the sample can be uniformly irradiated with the plasma. Here, for example, if the direction of the magnetic field is set in a direction perpendicular to the surface of the sample, the sample can be irradiated with plasma in a direction exactly perpendicular to the sample.

Since the generated magnetic field is extremely small as compared with the fourth conventional ECR plasma processing apparatus, the size of the magnetic field generating means, for example, the magnetic field generating solenoid coil, is greatly reduced. Can be
Thereby, there is an advantage that the plasma processing apparatus can be reduced in size and weight. Further, since the antenna 240 is not used unlike the fifth conventional example, the coupling between the electromagnetic wave of the rotating electric field and the plasma is not related to the generation of the plasma. It can be generated more stably.

In the above plasma processing apparatus,
Measuring means for measuring the density of the plasma generated in the plasma processing chamber, based on the density of the plasma measured by the measuring means, so that the density of the generated plasma is a predetermined value, the angular velocity and the A control means for controlling at least one of the phase difference and the DC magnetic field is provided, so that the coupling with the wave of the helicon wave in the generated plasma is controlled to be in an optimum state, and the density of the plasma is controlled. Can be controlled to a predetermined value.

[Brief description of the drawings]

FIG. 1 is a perspective view of a plasma processing apparatus according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view taken along line AA ′ of the plasma processing apparatus of FIG.

FIG. 3 is a cross-sectional view of the plasma processing apparatus of FIG. 1 taken along line BB ′.

FIG. 4 is a block diagram illustrating a microwave interferometer unit and a control unit of the plasma processing apparatus of FIG. 1;

FIG. 5 is a block diagram illustrating an electrode application signal generation circuit of the plasma processing apparatus of FIG. 1;

FIG. 6 is a longitudinal sectional view of a first conventional high-frequency plasma processing apparatus.

FIG. 7 is a longitudinal sectional view of a second conventional magnetron high-frequency plasma processing apparatus.

FIG. 8 is a longitudinal sectional view of a rotating magnetic field type high frequency plasma processing apparatus of a third conventional example.

FIG. 9 is a plan view showing an arrangement of three electromagnets in the rotating magnetic field type high frequency plasma processing apparatus of FIG.

FIG. 10 is a longitudinal sectional view of a fourth conventional ECR plasma processing apparatus.

FIG. 11 is a longitudinal sectional view of a fifth conventional helicon plasma processing apparatus.

FIG. 12 is a longitudinal sectional view of a plasma processing apparatus according to a modified example of the invention.

[Explanation of symbols]

Reference Signs List 10: plasma generation chamber, 11: plasma processing chamber, 12a: reaction gas transport pipe, 12b: exhaust pipe, 21, 22, 23, 24, 25: solenoid coil for generating magnetic field, 30: sample support table, 33: high frequency bias Signal generator, 50: Reference high-frequency signal generator, 60b, 60c, 60d, 60f, 60g, 60h: Phase shifter, 61: Variable phase shifter, 80: Microwave signal generator for control, 82, 87: Direction 85: Variable phase shifter, 88: Diode detector, 89: Current detector, 100: Controller, 300: Sample, ER1, ER2: Electrode group for generating a rotating electric field, ER11 to ER14, ER21 to ER24 ... Electrodes for generating a rotating electric field, E, E1, E2: rotating electric field, B: DC magnetic field, AN1, AN2: horn antenna.

────────────────────────────────────────────────── (5) References JP-A-6-45094 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/3065 C23F 4/00 H01L 21 / 31

Claims (4)

(57) [Claims] 1. A plasma processing apparatus for performing a predetermined process on a sample by generating plasma in a plasma processing chamber in which the inside is set to a vacuum state, wherein a plasma is generated in a direction toward the sample inside the plasma processing chamber. A plurality of rotating electric fields provided with magnetic field generating means for generating a DC magnetic field and provided at a predetermined angle from each other
A generating electrode, and a predetermined same angular velocity and a predetermined
One that has a phase difference and is perpendicular to the direction of the DC magnetic field
By generating an electric field having a direction,
Generates a rotating electric field that rotates in a direction perpendicular to the
A group of electric field generating means having a predetermined phase difference from each other
In order to generate a plurality of rotating electric fields, the plasma processing chamber
Inside the unit, a plurality of groups
Turns clockwise in the direction of the DC magnetic field
A plasma processing apparatus for generating a rotating electric field . 2. The plasma processing apparatus further comprises: measuring means for measuring a density of the plasma generated in the plasma processing chamber; and a density of the generated plasma based on the density of the plasma measured by the measuring means. 2. The plasma processing apparatus according to claim 1, further comprising control means for controlling at least one of the angular velocity, the phase difference between the plurality of rotating electric fields, and the DC magnetic field so that the predetermined value is a predetermined value. apparatus. 3. The plasma processing apparatus further includes another magnetic field for generating a magnetic field inside the plasma processing chamber together with the magnetic field generating means so that a magnetic flux of the generated DC magnetic field is focused to form a mirror magnetic field. 3. The plasma processing apparatus according to claim 1, further comprising a generation unit. 4. The plasma processing apparatus according to claim 1, wherein said plasma processing apparatus further comprises voltage applying means for applying a predetermined AC voltage to said sample.