JP3331542B2 - Surface treatment apparatus and method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface treatment apparatus and, more particularly, to a surface treatment apparatus capable of performing a surface treatment such as etching with high accuracy without damaging a workpiece.

[0002]

2. Description of the Related Art As one of surface treatment apparatuses, there is a dry etching apparatus for etching a neutral beam.

[0003] For example, Japanese Patent Application Laid-Open No. 62-259443 discloses a dry etching apparatus as shown in FIG.
A positive ion beam of a rare gas is extracted from the plasma generated by the ion source 150 by the DC discharge or the high-frequency discharge into the vacuum chamber 154 by the extraction electrode 152, and a rare gas ion of the same type as the rare gas ion extracted in the vacuum chamber 154 is formed. By converting the ion beam into a neutral beam (hereinafter also referred to as a neutral particle beam) by a resonance charge exchange reaction with a neutral rare gas, and irradiating the neutral beam onto the substrate S to be processed, An apparatus for etching a substrate S to be processed is disclosed.

In the above etching apparatus, the deflection electrode 158
Is provided, so that ions generated by the charge exchange reaction and ions extracted from the plasma source are deflected by the deflection electrode 158 so as not to reach the substrate S to be processed. In the figure, reference numeral 156 denotes a turbo molecular pump.

As another example of an etching apparatus, Japanese Patent Application Laid-Open No. Hei 1-120826 discloses a method as shown in FIG.
From the plasma generated in the discharge tube 164 by the microwave input from the microwave oscillator 160 via the waveguide 162, negative ions generated by the electron attachment reaction are extracted into a vacuum chamber 166 in a beam form from the plasma generated in the discharge tube 164. Is converted into a neutral beam by a charge exchange reaction, and the substrate S is etched by irradiating the neutral beam onto the substrate S through the grid electrode 168. In the figure, reference numeral 170 denotes an exhaust pump.

In this etching apparatus, a deflection magnet and an ion repelling electrode (grid electrode) 168 are provided in front of the substrate S to prevent electrons and ions from reaching the substrate S.

[0007] In a surface treatment apparatus such as the etching apparatus disclosed in the above-mentioned publication, there is an inherent need to uniformly treat the surface of a workpiece.

[0008]

However, in any of the etching apparatuses disclosed in the above-mentioned publications, the ion beam extracted from the plasma is transported in the vacuum chamber while the ion beam is charged between the charged particles in the beam. Since the ion beam is diverged by the Coulomb repulsion, the neutral beam generated by converting the ion beam into neutral is also in a divergent state. As a result, depending on the degree of divergence of the neutral particle beam, even if the beam reaches the substrate to be processed, neither uniform processing nor highly anisotropic processing can be performed on the substrate to be processed. It becomes impossible to perform etching with high precision.

In particular, the divergence of the ion beam increases as the transport distance increases, as the beam flux increases, or as the beam energy decreases.

On the other hand, regardless of whether a neutral beam is generated by a charge exchange reaction or an electron attachment reaction, the reaction efficiency increases as the relative velocity between the particles reacting with each other decreases, and the etchant increases. In order to reduce etching damage caused by collision with the substrate to be processed, the translational kinetic energy of the ion beam (hereinafter, simply referred to as energy) is preferably as small as possible.

As described above, in the above-described conventional etching apparatus, the generation of a neutral particle beam with low energy and high flux is incompatible with achieving uniform high anisotropic processing. There was a problem that it was impossible to satisfy both at the same time.

As described above, since the ion beam always diverges during transportation, only a diverged neutral beam can be obtained in principle. In particular, as shown in the etching apparatus shown in FIG. Is removed only by the deflection electrode 158, the neutral particles generated by the charge exchange reaction take over the movement direction of the ion beam at the time of charge exchange as it is. When ions having a movement direction that is not perpendicular to the ions are converted into neutral particles, the ions arrive non-perpendicularly to the object S,
It is impossible to etch a fine pattern with high accuracy, and the processing may be uneven in the surface direction of the processing target S, which may cause unevenness. Therefore, in order to perform fine etching processing with high accuracy, it is necessary to equalize the directions of the neutral beams reaching the workpiece S by some means.

In the surface treatment apparatus shown in FIG. 31, a plurality of mesh-like ion repulsion electrodes (also referred to as mesh electrodes) 168 are provided in front of the object to be processed (substrate) S. The positions of the micropores formed in the electrodes are substantially matched between the electrodes, and
Is a collimator, so that the ion repulsion electrode 16
Since it is possible to restrict the direction of the neutral beam passing through 8 to some extent, it is possible to perform fine etching with extremely high precision on the processing target S.

However, when the collimator (ion repulsion electrode) 168 composed of a plurality of mesh electrodes as described above is used, a neutral beam can pass through the minute hole of the collimator, but is blocked at a peripheral portion thereof. On the other hand, the surface of the object S corresponding to the peripheral portion becomes a shadow to which the neutral beam hardly reaches.

Therefore, when etching is performed by using the ion repelling electrode 168 as a collimator in the above-described surface treatment apparatus, fine processing can be performed with extremely high precision.
The microhole pattern of the collimator is transferred to the object S,
There is a problem that uniform processing cannot be performed since this causes unevenness in etching. This processing unevenness cannot be eliminated even if the transmittance of the collimator is increased no matter how much, and when the direction of the neutral beam is uniform, it occurs even when the number of ion repulsion electrodes is one.

Further, the neutral beam is applied to the ion deflection electrode 158 or the ion repulsion electrode 16 shown in FIGS.
In the surface treatment apparatus that irradiates the object S through 8, when exchanging the object S for performing the next process, the irradiation of the neutral beam is stopped for each process and the object S is exchanged. There is a need. In order to stop the irradiation of the neutral beam to the object S, the ion beam may be stopped. The method of stopping the ion beam is as follows. (1) Stop the generation of the plasma which is the source of the ion beam how to,
There are (2) a method of stopping the application of the voltage to the ion extraction electrode 152, and (3) a method of providing a shutter for blocking the ion beam during the transport of the ion beam.

However, in the method (1) for stopping the generation of plasma, a power source for generating the plasma is matched with the generated plasma for each processing, so that it takes a long time until the plasma is stabilized. This takes time, not only lowers the throughput of the process, but also changes the plasma generation status for each process, and may not be able to obtain stable processing conditions.

The method (2) for stopping the voltage application to the ion extraction electrode has the following problems. In a state where the ion beam is extracted from the plasma by the ion extraction electrode 152, a part of the ion beam collides with the electrode 152 to increase its temperature, causing the electrode 152 to change shape such as warpage. Since it has a stable shape at a certain position, an ion beam of a quality corresponding to the electrode shape is generated. Therefore, if the application of the voltage to the ion repulsion electrode 152 is stopped for each process, a stable ion beam cannot be obtained, so that a uniform process cannot be performed for each target object S.

Further, in the method (3) in which a shutter for blocking the ion beam is provided during the transport of the ion beam, it is not necessary to stop the generation of the plasma and the extraction of the ion beam each time the process is performed. Although the stability of the quality of the ion beam is superior to those of the two methods, since the ion beam is applied to the shutter, sputtering occurs, and the material of the shutter is filled as fine particles in the apparatus. The clean processing of the processing target S will be hindered. In addition, in the case of the surface treatment apparatus shown in FIG. 31, since the ion beam does not reach the ion repulsion electrode 168, thermal shape change occurs in the ion repulsion electrode 168 as in the case of the ion extraction electrode. Therefore, the condition under which the neutral beam passes through the ion repulsion electrode 168 changes for each process.

Therefore, there is a problem in that any of the above-described methods (1) to (3) cannot perform uniform processing on the object to be processed for each processing.

The present invention has been made to solve the above-mentioned conventional problems, and it is possible to uniformly perform a surface treatment such as highly anisotropic etching with a neutral particle beam having a low energy and a high flux. A first object is to provide a surface treatment apparatus that can perform the above-described steps.

The present invention also provides a surface treatment apparatus capable of performing a uniform processing (uniform processing) on a processing object with a neutral beam with high accuracy and in a width direction of the processing surface. This is a second problem.

The present invention further provides a surface treatment apparatus capable of performing a uniform treatment in a clean environment without lowering the throughput of the treatment for each treatment when the object to be treated is replaced. Providing is a third subject.

[0024]

According to the first aspect of the present invention, an ion beam extracted from a plasma is converted into a neutral beam,
The neutral beam passes through the ion repulsion electrode and is
At least one of an electrostatic field lens and a static magnetic field lens for preventing divergence of an ion beam in a space for converting an ion beam to a neutral beam in a surface treatment apparatus that irradiates an attached object and irradiates the surface with the object. The first problem has been solved by disposing one or two or more.

According to a second aspect of the present invention, there is provided the surface treatment according to the first aspect.
The static field lens and the static magnetic field lens,
At least one is arranged two or more .

[0026] The invention according to claim 3, in the surface treatment apparatus of the first aspect, the holder against the surface of the object plane
Be movable in at least one of the row and vertical directions
Thus, the first and second problems are simultaneously solved .

According to a fourth aspect of the present invention, there is provided the surface treatment according to the first aspect.
In the treatment device, the ion repulsion electrode has a mesh shape.
Ion repulsion electrode or collimator, ion repulsion electrode
Or, set the collimator in a direction parallel to the surface of the
And the first and the second
It is a solution to the problem .

According to a fifth aspect of the present invention, in the surface treatment apparatus of the first aspect , a medium is provided between the ion repulsion electrode and the holder.
The shutter for blocking the neutral beam
Thus, the first and third problems have been solved .

According to a sixth aspect of the present invention, in the surface treatment apparatus of the third aspect, the direction of the surface parallel to the surface of the object to be processed is adjusted.
The movement of the holder is limited to coaxial rotation, eccentric rotation and linear movement.
It is assumed that there is at least one.

According to a seventh aspect of the present invention, the surface treatment of the fourth aspect is provided.
Movement of ion repulsion electrode or collimator
Is at least one of coaxial rotation, eccentric rotation and linear movement
It is assumed that it is.

According to an eighth aspect of the present invention, in the surface treatment apparatus of the fourth aspect , the holder is flat with respect to the surface of the workpiece.
It can be moved in the line direction .

According to a ninth aspect of the present invention, in the surface treatment apparatus of any one of the first to fifth aspects, the ion beam is neutralized.
Excitation means for exciting a neutral beam generated in a space to be converted into a beam is provided.

The tenth aspect of the present invention is the above-described first to fifth aspects.
In any one of the surface treatment apparatuses, a temperature control means for controlling the temperature of the object to be processed is provided. Claim 11
The present invention provides a surface for converting an ion beam extracted from a plasma into a neutral beam, passing the neutral beam through an ion repulsion electrode, irradiating an object to be processed attached to a holder, and treating the surface. Ion anti-power generation in processing equipment
In addition to the poles, a velocity control electrode for accelerating and decelerating the ion beam is provided at a position close to the ion repulsion electrode in a space for converting the ion beam into a neutral beam. According to a twelfth aspect of the present invention, the ion beam extracted from the plasma is converted into a neutral beam, and the neutral beam is passed through an ion repulsion electrode, and is irradiated on an object to be processed attached to a holder to irradiate the surface thereof. in the surface treatment apparatus for treating, in a space to convert the ion beam into the neutral beam, Io
At least one of an electrostatic field lens and a static magnetic field lens for preventing the divergence of the electron beam is provided with one or two or more,
At a position close to the ion repelling electrode space for converting said ion beam into a neutral beam, separate from the ion repelling electrode
And a speed control electrode for accelerating and decelerating the ion beam. The invention according to claim 13 is a surface treatment method for converting an ion beam extracted from plasma into a neutral beam, passing the neutral beam through an ion repulsion electrode, irradiating an object to be treated, and treating the surface thereof, At least one of an electrostatic field lens and a static magnetic field lens is disposed in a space for converting an ion beam into a neutral beam, and one or more of the electrostatic field lens and the static magnetic field lens are provided.
By preventing the divergence of the ion beam,
Similarly, the first problem has been solved. Claim 1
According to a fourth aspect of the present invention, in the surface treatment method of the thirteenth aspect,
At least one of the electrostatic field lens and the static magnetic field lens is 2 or more.
It is arranged above. The invention according to claim 15 further converts an ion beam extracted from the plasma into a neutral beam,
In the surface treatment method, in which the neutral beam is passed through an ion repulsion electrode and irradiates an object to be processed attached to a holder to treat the surface thereof, the ion repulsion in a space for converting the ion beam into a neutral beam is performed. At a position close to the electrode,
Apart from the ion counter generating electrode, in which is disposed a speed control electrode for accelerating or decelerating the ion beam, and to reduce the high energy component of the neutral beam. Claim 16
The invention according to claim 1, wherein the electrostatic field lens and the static magnetic field lens both prevent divergence of the ion beam in the space and axial energy distribution of the ion beam in the surface treatment apparatus according to claim 1 or 2. Has a function of generating a local minimum value. The invention of claim 1 7, in claim 1 or 2 of a surface treatment apparatus, in the space, in which the ion beam is to be converted to a neutral beam by charge exchange reaction. The invention according to claim 18 is the surface treatment apparatus according to any one of claims 1 to 5 , wherein the target gas that undergoes charge exchange reaction with the ion beam is excited to excite the neutral beam to be converted. Excitation means is provided. According to a nineteenth aspect of the present invention, in the surface treatment method of the thirteenth or fourteenth aspect , both of the electrostatic field lens and the static magnetic field lens prevent divergence of the ion beam in the space and increase the energy of the ion beam. The minimum value is generated in the axial distribution. Claim
20. The surface treatment method according to claim 19 , wherein the energy of the ion beam is adjusted to an energy suitable for causing a reaction for converting the ion beam into a neutral beam in the space. It was done. Claim 2 to one aspect of the present invention, it claims 13, 14, 19 or 2
0 , wherein the ion beam is converted into a neutral beam by a charge exchange reaction in the space. The invention of claim 2 2, the ion beam extracted from the plasma into a neutral beam neutralizer chamber by charge exchange reaction, the neutral beam taken out from the neutral reduction chamber by passing through a ion repulsive electrode In the surface treatment method for treating the surface of the pair to be treated, in the neutralization chamber,
At least one of the electrostatic field lens and the static magnetic field lens is 1
Alternatively, the first problem is similarly solved by disposing two or more to prevent the divergence of the ion beam.
According to a twenty-third aspect of the present invention, there is provided the surface treatment method according to the twenty-second aspect.
Oite, the less of the electrostatic field lenses, and magnetostatic field lens
Is also provided with two or more of them.

[0034]

In the present invention, since at least one of the electrostatic field lens and the static magnetic field lens is disposed in the space for neutralizing the ion beam extracted from the plasma, the ion beam transported through the space has a low energy. Divergence can be prevented even when the flux is high and the flux is high, so that the neutron beam generated by the conversion of the ion beam can be prevented from diverging. As a result, the neutral particle beam having a low energy and a high flux can be prevented. Thereby, uniform high anisotropy surface processing can be performed.

In the case where at least one of the electrostatic field lens and the static magnetic field lens is plural, it is necessary to prevent the ion beam from diverging during the reaction of converting the ion beam into a neutral beam by charge exchange or electron attachment. It is possible to prevent energy and control energy. Therefore, the neutralization efficiency of the ion beam can be improved, and a neutral beam having a low energy and a high flux can be generated with a uniform direction without divergence. Can be achieved at high speed.

In the present invention, the holder can be moved in at least one of a direction parallel to and perpendicular to the surface of the object to be processed. Even when processing unevenness occurs on the surface of the object due to, for example, a shadow of the ion repulsion electrode or the collimator on the surface of the object, the object can be moved in a direction parallel to the surface. In addition, it is possible to prevent the occurrence of processing unevenness, and to perform uniform processing over the entire surface.

At this time, by assuming that the movement of the holder in the direction parallel to the surface of the object to be processed is at least one of coaxial rotation, eccentric rotation and linear movement, it is possible to ensure that processing unevenness occurs. Can be prevented.

Further, by making the holder movable in a direction perpendicular to the surface of the object to be processed, the ion repulsion electrode or the ion repulsion electrode can be adjusted according to the degree of divergence of the neutral beam passing through the collimator. Or because it is possible to appropriately adjust the separation distance between the collimator and the object to be processed,
Uniform treatment over the entire surface is possible.

In the present invention, since the ion repulsion electrode or the collimator can be moved in a direction parallel to the surface of the object, the angular distribution at which the neutral beam enters the object is limited. Therefore, even in a state where processing unevenness occurs due to the occurrence of these shadows on the surface of the object to be processed, by moving the ion repulsion electrode or the collimator, it is possible to prevent the occurrence of processing unevenness, It is possible to perform uniform processing over the entire surface of the object.

At this time, by assuming that the movement of the ion repulsion electrode or the collimator is at least one of coaxial rotation, eccentric rotation and linear movement, it is possible to reliably prevent processing unevenness.

Further, since the holder can be moved in a direction parallel to the surface of the object to be processed simultaneously with the movement of the ion repulsion electrode or the collimator, it is possible to more reliably prevent the occurrence of processing unevenness.

In the present invention, since a shutter for blocking a neutral beam is provided between the ion removing electrode and the holder, the object to be processed is irradiated with the neutral beam by the shutter. Can be reliably prevented, and it is possible to replace the processed object with a new object without stopping the generation of plasma or the application of voltage to the ion extraction electrode. The object can be processed under stable operating conditions, and uniform processing of the object can be performed.

Further, since the shutter is disposed behind the ion removing electrode (such as an ion repelling electrode and an ion deflecting electrode), the shutter is not irradiated with an ion beam.
Only the neutral beam will be irradiated. In general, the sputtering yield for the same material is smaller for a neutral beam than for an ion beam.
That is, the inside of the surface treatment apparatus can be maintained in a clean state as compared with the case where the ion beam is arranged during the transport of the ion beam.

Even when the ion removing electrode is an ion repelling electrode, the operating conditions from the plasma chamber to the ion repelling electrode can be kept constant, so that the ion repelling electrode can be prevented from being thermally deformed. The next process can also be performed stably under certain conditions.

Therefore, by disposing the shutter between the ion removal electrode and the holder, the object to be processed can be processed under a stable operation condition under a clean apparatus environment without lowering the throughput. Since it becomes possible, it becomes possible to perform uniform processing on the object to be processed for each processing.

In the present invention, when a speed control means for accelerating and decelerating the ion beam is provided, it becomes possible to control the translational kinetic energy of the ion beam, thereby improving the efficiency of the charge exchange reaction and generating the charge exchange reaction. The neutral beam can be controlled, for example, at a translation speed optimal for highly anisotropic etching.

For example, when a surface control apparatus provided with the electrostatic field lens or the static magnetic field lens for suppressing the divergence of the ion beam is provided with speed control means for accelerating and decelerating the ion beam, Since the efficiency of conversion into a neutral beam can be improved and the translational kinetic energy of the generated neutral beam can be appropriately adjusted, uniform surface treatment with high anisotropy and low damage can be achieved at high speed.

In the present invention, when the excitation means for exciting the neutral beam is provided, the neutral beam can be chemically activated, so that the etching rate can be further improved, for example. Becomes possible.

In the present invention, when the temperature control means for controlling the temperature of the object to be processed is provided, it is possible to set the object to be processed at a desired processing temperature and to maintain the entire object to be processed at the same temperature. Therefore, it is possible to reliably execute uniform processing on the entire surface of the object to be processed.

[0050]

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

FIG. 1 is a schematic sectional view showing an etching apparatus according to a first embodiment of the present invention. The etching apparatus of the present embodiment includes a plasma chamber 10 for generating a plasma P,
A neutralization chamber 14 for converting an ion beam extracted by the ion extraction electrode 12 from the plasma P generated in the plasma chamber 10 into a neutral beam, and a neutral beam generated in the neutralization chamber 14 are introduced. And a processing chamber 16 for surface-treating the object to be processed with the neutral beam.

[0052] the plasma chamber 10 in order to generate the flop plasma by electron cyclotron resonance (ECR), the waveguide 18 for introducing microwaves from the microwave source (not shown) is connected, and the Plasma chamber 10
An electromagnet 20 for ECR is disposed around the periphery.
Although not shown, the plasma chamber 10 is connected to a gas introduction pipe (not shown) for introducing a raw material gas and a vacuum exhaust device for bringing the inside to a desired reduced pressure state.

The ion extraction electrode 12 is connected to a power supply (not shown), and is configured to apply a negative potential to the plasma P in order to extract positive ions from the plasma P generated in the plasma chamber 10. .

Between the neutralization chamber 14 and the processing chamber 16, ions passing through the neutralization chamber 14 or generated in the neutralization chamber 14 are introduced into the processing chamber 16. An ion repulsion electrode 22 for preventing the
Only neutral beams and thermal motion neutral particles are introduced into the chamber.

A vacuum exhaust pipe 24 connected to a vacuum evacuation device (not shown) is connected to the processing chamber 16 so that the pressure inside the processing chamber 16 can be adjusted. Is provided with a holder 26 for mounting a substrate (object to be processed) S.

The holder 26 has a temperature control function for the substrate S to be processed. More specifically, as shown in an enlarged sectional view of FIG. The temperature of the substrate S can be controlled.

In the present embodiment, two separated first electrodes 28 and a second electrode 30 located therebetween are arranged in a ring shape around the inside of the neutralization chamber 14. I have. The two first electrodes 28 are grounded and the second
The positive potential is applied to the electrode 30, and the first electrode 28 and the second electrode 30 constitute an electrostatic field lens.

In this embodiment, as described above, since the electrostatic field lens composed of the combination of the first electrode 28 and the second electrode 30 is provided, the ion extraction electrode is formed from the plasma P generated in the plasma chamber 10. When the ion beam I is drawn out to the neutralization chamber 14 by the use of 12, the divergence of the ion beam I can be prevented as shown by a broken line in the figure.

FIG. 3 is a diagram showing the axial distribution of the electrostatic potential and the ion beam energy in the neutralization chamber 14 during the etching. In addition,
In the figure, Ei is the ion beam energy.

Since the etching apparatus has only one electrostatic field lens, the distribution curve of the ion beam energy has a shape having one peak due to the potential generated by the electrostatic field lens.

As described above, according to the present embodiment, it is possible to prevent the ion beam from being diverged in the neutralization chamber 14,
Therefore, the divergence of the generated neutral beam can be prevented, and ions and electrons are generated by the ion repulsion electrode 22 in the processing chamber 1.
6 can be prevented from being introduced into the processing chamber 16, only the neutral particle beam N can be introduced into the processing chamber 16, and the substrate S attached to the holder 26 can be etched by the neutral beam N. . Accordingly, the substrate S can be etched by the low-energy neutral particle beam N having a uniform direction, so that the substrate S can be uniformly etched with high anisotropy and low damage.

Further, since the temperature of the substrate S to be processed can be controlled as described above, for example, the reaction of a chemically active radical can be controlled. As a specific example, by introducing a coolant such as liquid nitrogen into the holder 26 and controlling the temperature of the substrate S to around −100 ° C., it is possible to suppress isotropic etching caused by radicals, and to further increase the temperature. Anisotropic etching can be achieved.

FIG. 4 is a sectional view, corresponding to FIG. 1, showing an etching apparatus according to a second embodiment of the present invention.

The etching apparatus of the present embodiment uses the neutralization chamber 1
4 around the inner periphery of the four first electrodes 2
8 and three second electrodes 30 located between the first electrodes, and the etching apparatus of the first embodiment is different from the etching apparatus of the first embodiment except that a total of three lenses are installed in combination with these. Substantially the same.

FIG. 5 is a diagram corresponding to FIG. 3 showing the axial distribution of the electrostatic potential and the ion beam energy in the neutralization chamber 14 in this embodiment. As is clear from the comparison of FIG. 5 with FIG. 3, the etching apparatus of the present embodiment has a beam energy in the neutralization chamber 14 which takes a certain value more frequently than the apparatus of the first embodiment.
The average value of the beam energy can be changed by changing the potential applied to the electrostatic field lens.

Considering the case where ions are neutralized by the charge exchange reaction, it is well known that the smaller the energy of the ions, the higher the charge exchange efficiency. However, since the beam diverges due to Coulomb repulsion between the ions, it is set. There is a lower limit on the beam energy that can be performed.

The largest factor that determines the lower limit value is the ion beam flux, but there is no fixed value because it depends on the etching conditions. Now, FIG.
If the beam energy Ech shown in FIG. 5 is the lower limit energy value, the etching apparatus of the present embodiment can perform the charge exchange reaction with higher efficiency than the etching apparatus of the first embodiment. . In fact, in the case of this example, the efficiency of the charge exchange reaction was obtained about three times that of the first example.

As described above in detail, according to this embodiment, as in the first embodiment, it is possible to prevent the ion beam extracted from the plasma from diverging, and to neutralize the ion beam to generate the ion beam. Since the diverging neutral particle beam can also be prevented from being diverged, highly anisotropic etching can be achieved.

Further, according to this embodiment, by installing the electrostatic field lens in a plurality of stages, the ion beam is converted to an energy suitable for causing a chemical reaction such as a charge exchange reaction to convert the ion beam into a neutral beam. Since the energy can be adjusted, it is possible to cause an exchange reaction with high efficiency.

Next, using the etching apparatus of this embodiment, the polysilicon (po) deposited on the silicon substrate is used.
The result of actually etching the (ly / Si) layer will be described.

In the plasma chamber 10, chlorine (C1 ₂ ) is converted into plasma, and the generated plasma is supplied to the neutralization chamber 14 with C1 ^+.
And an ion beam consisting of C1 ₂ ⁺ is extracted, the ion beam is neutralized with C1 ₂ (target gas) to generate a neutral beam, and the neutral beam is applied to a silicon substrate attached to the holder 26. was etched polysilicon layer, sufficiently practical etching rate 200 0
Simultaneously with Å / min was obtained, since it was possible to parallel transported without diverging the ion beam before charge exchange, it was possible to produce a neutral beam direction are aligned. Therefore, the neutral particle beam can be perpendicularly incident on the silicon substrate, and as a result, highly anisotropic etching sufficiently practical for fine processing of the 0.5 μm rule can be achieved.

FIG. 6 is a sectional view, corresponding to FIG. 1, showing an etching apparatus according to a third embodiment of the present invention.

The etching apparatus of the present embodiment uses the neutralization chamber 1
Two electrostatic field lenses each including two first electrodes 28 and an intermediate second electrode 30 are disposed around the inside of the electrode 4, and the ion beam is accelerated / decelerated to a position close to the ion repulsion electrode 22. It is substantially the same as the etching apparatus of the first embodiment shown in FIG. 1 except that a ring-shaped speed control electrode 32 is provided.

In this embodiment, the speed control electrode 3
2, the divergence of the ion beam can be prevented by the electrostatic field lens and the directions can be aligned in parallel, as in the etching apparatus of the first or second embodiment. It is possible to adjust to a desired energy (speed).

The case where the ion beam is decelerated will be specifically described with reference to FIG. FIG. 7 shows a half-section (lower side) in the radial direction when the center of the cylinder of the neutralization chamber 14 having the radius R and the length L is taken along the Z axis. The position on the left end in the figure corresponds to the ion extraction electrode 12, and the ion repulsion electrode 22 is located on the right end. Here, R = 0.
08m and L = 0.38m are used. However, it goes without saying that the device size is not limited to this.

The ion extraction electrode 12 is grounded, a positive voltage of 950 V is applied to the ion repulsion electrode 22, and an equipotential surface (in the Z axis direction) perpendicular to the Z axis having a gradient as shown in FIG. (Not shown). Further, all the first electrodes 28 of the electrostatic field lens (three sets of electrostatic field lenses are used for convenience) are grounded, and the second electrode 30 is set to 300 V, from the side closer to the ion extraction electrode 12. 20
Each voltage of 0 V and 1300 V is applied to align the positive ions extracted by the ion extraction electrode 12 in parallel with the Z axis, and 950 V is applied to the speed control electrode 32 to apply a positive ion beam. The speed is slowing down.

The voltage applied to each of these electrodes is not fixed, and is set to an optimum voltage so that the direction of the ion beam is uniform and the speed is appropriate during an actual operation. When accelerating the ion beam, a voltage opposite to that for decelerating the speed control electrode 32 is applied.

FIG. 9 shows the transport distance of the ion beam, that is, the ion extraction electrode in the neutralization chamber 14 when a positive voltage is applied to the speed control electrode 32 and the ion beam is decelerated in the etching apparatus of this embodiment. FIG. 10 shows the energy of the ion beam for a length from 12, and FIG. 10 shows the energy distribution of the neutral beam generated by the charge exchange reaction at that time. FIG. 11 shows the speed control electrode 3 for comparison.
2 shows the energy distribution of the neutral beam in the case where No. 2 is not used.

It can be seen from FIG. 9 that the energy (velocity) of the ion beam decreases as the transport distance increases, and as is clear from a comparison between FIG. 10 and FIG. It can be seen that by slowing down the ion beam, a low energy component can be generated in the neutral beam, and a high energy component can be effectively reduced. Therefore, at the time of etching, the substrate S
Can be reduced, and the speed of the ion beam is reduced, so that the conversion efficiency from the ion beam to the neutral beam is improved for the above-mentioned reason.

FIG. 12 shows the energy distribution of the neutral beam when the ion beam is accelerated. From the comparison between FIG. 12 and FIG. 10, the high energy component of the neutral beam generated by accelerating the ion beam is shown. It can be seen that can be reduced. However, when accelerating the ion beam,
In some cases, it may be necessary to lower the current density of the ion beam initially extracted by the ion extraction electrode, as compared with the case where the speed is reduced so as not to diverge. Whether the ion beam is accelerated or decelerated is appropriately selected depending on conditions for processing the substrate S to be processed, that is, the type of the substrate, the required etching rate, the degree of damage, and the like.

FIG. 13 is a sectional view, corresponding to FIG. 6, showing an etching apparatus according to a fourth embodiment of the present invention.

The etching apparatus according to the third embodiment shown in FIG. 6 is different from the etching apparatus according to the third embodiment shown in FIG. Substantially the same as the device.

In the present embodiment, similarly to the third embodiment, the direction of the ion beam can be aligned and the speed thereof can be appropriately controlled. Since the active beam can be brought into a chemically excited state, highly accurate etching can be performed at a higher speed.

FIG. 14 is an energy phase diagram conceptually showing the principle of converting a neutral beam generated from an ion beam by a charge exchange reaction by the excitation device 34 into a neutral beam in an excited state simultaneously with the reaction.

In the charge exchange reaction without the excitation device 34, the target gas T is in the ground state indicated by A in the figure, and the generated neutral beam N is also in the ground state indicated by B.

In this embodiment, since the target gas T can be brought into the excited state indicated by A ^* by the excitation device 34, the neutral beam N generated by the charge exchange reaction is brought into the excited state indicated by B ^*. be able to. At that time, the excited state is maintained until the neutral particles in the excited state generated by the excitation device 34 are transported to the space where the charge exchange with the ion beam I is performed. The energy gap ΔE _T between the excited state A ^* and the ion state A ⁺ of the gas T and the ion beam I
Excited state B ^* and ion state B ⁺ (original ion beam)
The condition is that the energy gaps ΔE _i are almost equal or ΔE _T <ΔE _i .

In general, ion beam particle species and target
When the neutral particle species is the same, ΔE _T= ΔE_iIs
Therefore, it is desirable to use the same particle species for the charge exchange reaction.
Preferably, it is possible even between different kinds of particles depending on conditions.
The required lifetime of the neutral particles in the excited state is determined by the equipment size.
Although it differs depending on the size, it is usually sufficient if it is about μsec or more.

In the present embodiment, an X-ray generator or any one of ultraviolet, visible and infrared light generators is used as the excitation device 34, and the neutral beam generated by the charge exchange reaction is photoexcited. Alternatively, a neutral beam may be excited by electron collision using a low energy electron beam generator. The installation position of the excitation device 34 is shown in FIG.
The position is not limited to the position shown in the above, and can be arbitrarily changed as long as the position can excite neutral particles.

Next, the results of actually etching the polysilicon layer deposited on the silicon substrate using the etching apparatuses of the third and fourth embodiments will be described.

In the plasma chamber 10, Cl ₂ gas is turned into plasma, an ion beam composed of Cl ⁺ and Cl ₂ ⁺ is extracted from the generated plasma into the neutralization chamber 14, and the ion beam is neutralized by a charge exchange reaction to be neutralized. When a neutral beam was generated and the polysilicon layer on the silicon substrate S attached to the holder 26 was etched with the neutral beam, the result shown in FIG. 15 was obtained.

FIG. 15 shows the results (etching rates) when the etching apparatuses of the third and fourth embodiments were applied, the results obtained by the conventional method for comparison, and the results of the first and second examples for reference. The results of the second embodiment are also shown. The conventional method used here is a case where an apparatus having a structure shown in FIG. 31 is used.

In each of the etching apparatuses of the first to fourth embodiments, the initial energy of the ion beam, the flux thereof, and the gas pressure of the neutralization chamber 14 are all set to be equal, and are 500 eV and 1 mA / cm ² , respectively. , 3 × 10 ⁻⁴ Torr. In the third and fourth embodiments, the ion beam
0 eV, and especially in the fourth embodiment, the excitation device 34
Using an RF discharge plasma apparatus for generating neutral particles in an excited state, the Cl ^* atoms and Cl ₂ ^{* in the} excited state ^.
Generated molecule.

According to the etching apparatuses of the third and fourth embodiments, it was possible to obtain a sufficiently practical etching rate (rate) of 1500 to 2000 ° / min.
Also, with the etching apparatuses of the first and second embodiments described above, an etching rate 10 times or more as compared with the conventional method could be obtained.

FIG. 16 is a schematic sectional view showing one static magnetic field lens applied to the etching apparatus of the fifth embodiment according to the present invention.

The etching apparatus of the present embodiment uses one or more static magnetic field lenses 36 shown in FIG. 16 instead of the electrostatic field lenses (first electrode 28 and second electrode 30) shown in FIG. Except for the arrangement, it is substantially the same as the etching apparatus of the first embodiment.

FIG. 16 shows the static magnetic field lens 36 in a cross section in a plane including the Z axis when the center of the cylinder of the neutralization chamber 14 is set to the Z axis.
It has a structure that is rotationally symmetric about the Z axis. The static magnetic field lens 36 is composed of a yoke 36A having a rectangular frame-shaped cross section with a part cut away, and a coil 36B fitted in the yoke so that the ion beam passes through a space having an inner diameter d. Has become.

The shape of the magnetic field (magnetic field intensity distribution on the Z axis) formed by the static magnetic field lens 36 is made to be bell-shaped as shown in FIG. The magnetic field strength distribution on the Z axis is given by the following equation (1). The focal length f of the static magnetic field lens at this time is expressed by the following equation (2).

B (Z) = B ₀ / {1+ (Z / d) ² } (1) f = d / sin (π / ω) (2) ω = (1 + k ² ) ^1/2 where , K are parameters representing the strength of the lens,
It is proportional to the coil current and the number of turns of the coil.

In this embodiment, the ion beam can be converged by forming a magnetic field having the above-described intensity distribution. Although the static magnetic field lens has a larger shape than the electrostatic field lens, it has the advantage of being able to cope with a wide range of beam energies. Divergence can be suppressed.

Therefore, according to the present embodiment, as in the first to fourth embodiments, the divergence of the ion beam can be prevented and its direction can be uniformed. Etching becomes possible.

In the etching apparatus of the present embodiment, the speed control electrode 32 may be provided similarly to the third embodiment, or the excitation apparatus 34 may be provided. These two may be provided side by side similarly to the embodiment.

FIG. 17 is a sectional view showing a schematic structure of an etching apparatus according to a sixth embodiment of the present invention.

In the etching apparatus of this embodiment, two ion repulsion electrodes 22 are arranged close to each other, the positions of the fine holes formed in the two are aligned in the plane direction, and the two ion repulsion electrodes 22 are collimated. 38, the electrostatic field lens and the static magnetic field lens used in the first to fifth embodiments are excluded. Also, the processing surface (surface) of the processing target substrate S attached to the holder 26 can be moved in a direction parallel to the processing surface (a direction perpendicular to the neutral beam incident direction). The holder 26 is movable.

The etching apparatus of this embodiment is substantially the same as the etching apparatus of the first embodiment, except for the features described above. However, the electromagnet 20 is divided into a plurality,
The gas inlet pipe 19 is clearly shown.

FIG. 18 shows the holder 2 of the etching apparatus.
FIG. 6 is an enlarged plan view when 6 is viewed from a direction perpendicular to a processing surface of a substrate S attached thereto.

In this embodiment, as shown in FIG. 18, the holder 26 is coaxially rotated about the center O of rotation of the substrate S mounted on the holder.
Therefore, by coaxially rotating the holder 26, it is possible to similarly apply coaxial rotation to the processing surface of the substrate S attached to the holder 26.

In this embodiment, since the two ion repulsion electrodes 22 constitute the collimator 38 for limiting the direction of the neutral particle beam as described above, the substrate S is fixed on the substrate S in a fixed state. However, the unevenness of the distribution of the neutral beam flux caused by the ion repulsion electrode 22 occurs, causing processing unevenness. As described above, since the holder 26 is coaxially rotated, the processing unevenness is reduced. This can be prevented.

However, as shown in FIG.
In the case where one substrate S is attached to 6, when the above-described coaxial rotation is performed, the portion of the substrate S to be processed which is in contact with the rotation center O is not affected by the rotation. Therefore, the substrate S at the center of rotation O has a disadvantage that a difference in processing speed occurs between the other portion and the other portion. However, since the portion other than the center is uniformly irradiated with the neutral beam,
Processing unevenness can be significantly reduced as compared with the case where coaxial rotation is not performed.

In addition, in the case where a plurality of substrates S are mounted on the holder 26 for simultaneous processing, the above drawbacks can be solved by mounting each substrate S with the rotation center O of the holder 26 removed.

Next, an etching apparatus according to a seventh embodiment of the present invention will be described. As shown in FIG. 19 corresponding to FIG.
Is substantially the same as the etching apparatus of the sixth embodiment, except that is capable of eccentric rotation.

That is, when a single substrate S is mounted on the holder 26, the same coaxial rotation about the same O as that of FIG. It was made possible.

In this embodiment, the coaxial rotation center O located substantially at the center of the substrate S to be processed also moves in a direction parallel to the processing surface of the substrate S in accordance with the eccentric rotation of the holder 26. As in the case of the example, the processing unevenness does not occur between the processing target substrate S corresponding to the rotation center O and the other portions, so that even with the single substrate S, the entire processing can be performed uniformly. .

Next, an etching apparatus according to an eighth embodiment of the present invention will be described. In the etching apparatus of this embodiment, as shown in FIG. 20 corresponding to FIG. 18, the holder 26 can simultaneously perform coaxial rotation about O and linear reciprocating motion in a direction parallel to the processing surface of the substrate S. Except for
This is substantially the same as the etching apparatus of the sixth embodiment.

In this embodiment, since the holder 26 is coaxially rotated and simultaneously reciprocates in a straight line, uniform processing can be performed on the entire substrate S. In the present embodiment, since the coaxial rotation is adopted, the device structure is simpler than that of the seventh embodiment. However, for example, in order to uniformly irradiate the neutral beam to the entire substrate S to be processed, If the reciprocating movement is performed by a distance corresponding to the diameter of the substrate S, it is necessary to increase the size of the apparatus by the length.

Next, an etching apparatus according to a ninth embodiment of the present invention will be described. The etching apparatus of the present invention includes:
As shown in FIG. 21, the main part of the holder 26 is similar to that shown in FIG. 21 except that the holder 26 can be moved back and forth in the direction perpendicular to the processing surface of the substrate S, that is, in the direction of the ion repulsion electrode 22. This is substantially the same as the etching apparatus of the sixth embodiment shown in FIG. However, the sliding shaft 26A of the holder 26
Is fitted with a bellows 40 to prevent foreign matter from diffusing into the apparatus during operation.

In this embodiment, since the distance between the collimator (two ion repulsion electrodes 22) 38, which is a neutral beam source, in the processing chamber 16 and the holder 26 is variable, the processing surface of the substrate S can be changed. It is possible to adjust the separation distance to the collimator 38 appropriately. Therefore, when the directivity of the neutral beam passing through the collimator 38 is high, if the distance between the collimator 38 and the substrate S to be processed is short, the shadow of the collimator 38, that is, the neutral beam does not pass by the collimator. The part is transferred to the substrate S to be processed,
Although processing unevenness occurs, the processing unevenness can be prevented by setting the substrate S at an appropriate distance from the collimator 38 in accordance with the degree of divergence of the neutral beam passing through the collimator 38.

That is, as shown in FIG. 22, the relationship between the substrate S and the collimator 38, the directivity of the neutral beam is set by setting the substrate S at a position where the neutral beam passing through the collimator 38 overlaps. , It is possible to effectively prevent the occurrence of processing unevenness, and uniform processing becomes possible.

FIG. 23 is a schematic sectional view corresponding to the AA section shown in FIG. 17 showing the features of the tenth embodiment according to the present invention.

The etching apparatus of this embodiment is similar to that of FIG.
As shown in FIG.
A to 50C, and can be rotated in a direction parallel to the processing surface of the substrate S (a direction perpendicular to the direction of incidence of the neutral beam). This is substantially the same as the etching apparatus of the sixth embodiment.

FIG. 24 is an enlarged cross-sectional view showing the ion repulsion electrode 22 and its vicinity when the inside of the etching apparatus is viewed from the vertical direction, and FIG. FIG. 4 is a partial plan view seen from above.

In the above etching apparatus, power is transmitted only to the gear 50A from the motor 52 installed outside the vacuum chamber 14A of the neutralization chamber 14, and the two disk-like ion repulsion electrodes 22 are transmitted by the gear 50A. It is designed to be driven to rotate.

The rotation driving mechanism of the ion repulsion electrode 22 will be described in detail. The rotational driving force from the motor 52 is transmitted through a rotation introducing device 54 to a worm gear 58 located in a gear case 56 via a shaft 58A, and the driving force is transmitted to a flat gear 60 in the gear case 56.
It is transmitted as a rotational driving force whose direction has been changed by 90 °.

The flat gear 60 is provided with a gear mounting plate 62.
Connected to the end of a rotating shaft 64 supported by
The other end of the gear 4 is similarly connected to the gear 50A.
The gear 50A is composed of two sheets insulated from each other with an insulating spacer 66 made of alumina or the like interposed therebetween. The lower gear 50A is an insulating spacer provided between the gear 50A and the gear mounting plate 62. 66 also insulates itself from the apparatus body.

The two gears 50A are meshed with gear ridges formed at the same pitch around the two ion repulsion electrodes 22, respectively.

The gear 50A transmits a rotational driving force to the ion repulsion electrode 22, and also functions as a conductor for applying a desired voltage to the ion repulsion electrode 22. That is, as shown in FIG. 25, in the gear 50 </ b> A, the disk 68 is in contact with the outer periphery of the guide, and the strength of the contact can be adjusted by the spring 70. This disk 68
Rotates about a shaft 68A, and the rotation shaft 68A is fixed to one end of an arm 72, and the other end of the arm 72 is rotatably supported by a support shaft 74 made of an insulating material such as alumina. A voltage is applied to the arm 72 by a lead wire 78 introduced through a field through 76.

The arm 72, the disk 68, the gear 50A,
Since each of the ion repulsion electrodes 22 is made of metal, it is possible to apply a desired voltage to the ion repulsion electrode 22 by applying a voltage to the arm 72 via the lead wire 78. In FIG. 25, reference numeral 80 denotes a shielding plate. In FIG. 25, the shielding plate 80 is omitted.

As described in detail above, according to the present embodiment, 2
A desired voltage can be applied to each of the ion repulsion electrodes 22, and the rotational driving force of the motor 52 is transmitted to the two gears 50A, so that the two ion repulsion electrodes meshed with each other. Since the electrode 22 can be rotated coaxially, when the ion repulsion electrode 22 is fixed, it functions as a collimator, so that the opening pattern of the ion repulsion electrode 22 is transferred to the substrate S to be processed. The processing unevenness can be effectively prevented, and the substrate S can be uniformly processed.

In the above-mentioned etching apparatus, the case where the ion repulsion electrode 22 has a perfect circular shape has been described. However, when the electrode 22 has a perfect circular shape, the center of rotation does not move. If the substrate S to be processed is attached, processing unevenness occurs near the center of the substrate S. In this case, the holder 26 is placed in a direction perpendicular to the neutral beam (parallel to the processing surface of the substrate S). It is desirable to incorporate a mechanism that translates in the same direction and move in the same direction. In this way, even when the number of substrates S to be processed is one, uniform processing can be reliably performed over the entirety.

When a chemically active gas such as chlorine or fluorine is used for the surface treatment, the motor 52 for rotationally driving the ion repulsion electrode 22 is installed outside the vacuum vessel 14A as described above. Although it is better to perform it, it may be installed in the vacuum vessel 14A in some cases.

In order to apply a voltage to the gear 50A, it is preferable to use the disk 68 because it is possible to keep the inside of the apparatus clean if the sliding portion is not installed in the vacuum vessel 14A. A brush terminal used for a motor may be used.

The ion repulsion electrode 22 is not a perfect circle,
For example, the shape may be elliptical. In this case, the gear 50A
Is fixed, and the remaining gears 50B and 50C can be moved in parallel with respect to the rotation plane, whereby the elliptical ion repulsion electrode can be similarly rotated.

As described above, when the ion repelling electrode 22 is formed in an elliptical shape, the hole for the collimator provided on the ion repelling electrode is turned to any hole with respect to the substrate S by the rotation of the electrode. Because you can change that position,
Processing unevenness can be eliminated without moving the holder 26 in parallel. In the case where the ion repulsion electrode 22 is formed in an elliptical shape, the mechanism for moving the holder as described above is not required, so that there is an advantage that the structure of the device can be simplified, and therefore, the device can be manufactured at low cost.

FIG. 26 is a schematic sectional view corresponding to FIG. 17 showing an etching apparatus of an eleventh embodiment according to the present invention.

The etching apparatus according to the present embodiment includes a disc-shaped shutter 82 between the ion repulsion electrode 22 and the holder 26.
Is provided so as to be rotatable around a rotation shaft 82A mounted near the edge thereof, and a part of a wall portion of the processing chamber 16 is enlarged in diameter as a moving space for enabling the shutter 82 to rotate. Otherwise, the etching apparatus is substantially the same as the etching apparatus of the sixth embodiment (FIG. 17).

FIG. 27 is an enlarged perspective view showing only the shutter 82. The shutter 82 is made of carbon (C).

In the present embodiment, as described above, the shutter 82 is provided between the ion repulsion electrode 22 and the holder 26.
By accommodating 2 in the enlarged diameter portion 16A, the substrate S to be processed can be subjected to highly anisotropic etching with a neutral beam.

When the processing of the substrate S is completed and it is to be replaced with the next substrate S, the shutter 82 is
By rotating the substrate A around the center and moving it to the position shown in FIG. 26, the irradiation of the substrate S with the neutral beam can be cut off, so that the substrate S can be replaced.

Therefore, according to the present embodiment, since the neutral beam can be cut off behind the ion repulsion electrode 22, the operation of the etching apparatus can be continued even when the substrate S is replaced, and the plasma chamber 10, the ion extraction electrode 12, Since the neutralization chamber 14, the ion repulsion electrode 22, and the like can be maintained in the same state, the replaced substrate S can be processed under the same operating conditions as the previous processing. Therefore, it is possible to perform uniform processing on the substrate S for each processing under stable conditions.

Further, according to the present embodiment, the ion repulsion electrode 2
Since only the neutral beam is blocked by the shutter 82 behind the shutter 2, the sputtering amount of the shutter can be greatly reduced as compared with the case where the shutter is installed in the neutralization chamber 14 and the ion beam is blocked. Thus, the inside of the apparatus can be maintained in a clean state.

In the present embodiment, the shutter 82 made of carbon is used, but the invention is not limited to this.

As a material for forming the shutter 82, it is desirable that the sputtering yield by the neutral beam irradiation is small and the processing is easy. Considering workability, metal is good, but considering sputtering yield, C, Ti,
V, W, Mo, Co, Cr, Ni, Cu, and Au increase in this order. While referring to this, the actual material can be selected in consideration of the neutral beam type to be used. Among them, carbon (C) is suitable when a neutral beam such as argon (Ar) or xenon (Xe), which is chemically inert, is used because the sputtering yield is as small as about 1/10 of titanium (Ti). It is.

When an insulating material such as ceramic is used as the shutter material, Al ₂ O ₃ , SiC, Si
Since the sputtering yield is smaller in the order of O _{2 and the} like, the selection can be made with reference to this.

In this embodiment, in order to store the shutter 82 when not in use, a part of the enlarged diameter portion 16
Although A is formed, the entire diameter of the vacuum vessel of the etching apparatus may be made large enough to allow the shutter 82 to move. However,
When the entire diameter is increased in this way, there is no inconvenience as long as the apparatus is continuously operated, but, for example, when evacuating during maintenance, the required time is long because the volume of the vacuum vessel is large. Since a disadvantage arises, it is more reasonable to provide a partially enlarged portion 16A as shown in FIG.

FIG. 28 is a schematic sectional view corresponding to FIG. 26, showing an etching apparatus of a twelfth embodiment according to the present invention.

[0145] The etching apparatus of the present embodiment includes a shutter 8
2 except that a camera-type shutter was used.
This is substantially the same as the etching apparatus of the first embodiment.

FIG. 29 is an enlarged plan view showing the camera type shutter 82, and FIG.
2B shows a state in which the shutter 82 is closed, and FIG. 2B shows a state in which the shutter 82 is half opened.

In this embodiment, the camera-type shutter 82 is made of carbon. However, it is needless to say that another material may be used as the material for the formation according to the criteria described in the eleventh embodiment.

According to the present embodiment, since the camera-type shutter 82 is employed to cut off the neutral beam, the first
As in the first embodiment, a stable and uniform process can be performed on the substrate S for each process. Further, the enlarged diameter portion 16 as shown in FIG.
Since there is no need to provide A, the structure can be made simple, for example, in a cylindrical shape, and there is also an advantage that the etching apparatus can be manufactured easily and at low cost.

As described above, the present invention has been specifically described. However, the present invention is not limited to the above-described embodiment, and can be variously modified without departing from the gist thereof.

For example, in the embodiment, the case where the electrostatic field lens and the static magnetic field lens are separately used as the lens for preventing the divergence of the ion beam is shown, but both may be combined. Further, the specific shape of the static magnetic field lens is not limited to the one described in the above embodiment.

In the above embodiment, the case where the holder has the function of cooling the object to be processed has been described, but the present invention is not limited to this. Depending on the object to be treated, it may be better to raise the temperature to activate the radical reaction. In this case,
This can be achieved by providing a heating function to the holder by placing a heating element such as SiC in the holder.

The energy for generating plasma in the plasma chamber is not limited to microwaves, but may be any other energy such as a radio wave or a DC electric field for converting gas into plasma.

Also, as in the first to fifth embodiments, the etching apparatus in which the direction of the ion beam is aligned by the electrostatic field lens or the static magnetic field lens can be used in the sixth to eighth embodiments (FIG. 17).
As shown in FIGS. 20 to 20, the holder 26 may be moved (rotated, eccentrically rotated, or moved straight) in a direction parallel to the processing surface of the substrate S, and the ninth embodiment (see FIG. 20). 21)
, The distance between the holder and the ion repulsion electrode 22 may be adjusted. Further, as in the tenth embodiment (FIGS. 23 to 25), the ion repulsion electrode 22 is rotated or decentered. You may make it rotatable.

Further, the holder 26 may be configured to be able to perform not only an operation such as rotation parallel to the processing surface of the substrate S, but also an operation in a direction perpendicular to the processing surface. The operation such as the rotation of the ion repulsion electrode 22 may be performed together with the operation in the vertical direction.

Further, the ion repulsion electrode and the collimator may be moved linearly.

Further, in the above-described embodiment, the case where the collimator is formed by two ion repulsion electrodes has been described, but the present invention is not limited to this.

The etching apparatus of the sixth to twelfth embodiments (FIGS. 17 to 26, 28, etc.) is provided with a speed control electrode 32 for controlling the speed of the ion beam, and for exciting the neutral beam. May be provided in parallel.

Further, in the above-described embodiment, the case where the number of shutters is one is shown, but two or more shutters may be provided in parallel.

The surface treatment apparatus is not limited to the dry etching apparatus, but may be, for example, a sputtering apparatus or a film forming apparatus.

[0160]

As described above, according to the present invention, since the divergence of the ion beam extracted from the plasma is prevented by using at least one of the electrostatic field lens and the static magnetic field lens, highly anisotropic etching is performed. And other uniform surface treatments can be achieved.

In the case where a plurality of lenses are installed, it is possible to control the beam energy during the reaction in which the ion beam is neutralized, so that the neutral beam can be generated with high conversion efficiency. In addition, since a neutral beam with low energy can be obtained, surface treatment such as etching with low damage and high anisotropy can be achieved.

Further, according to the present invention, when irradiating a neutral beam converted from an ion beam to a target object, the holder for mounting the target object is rotated, moved linearly in a direction parallel to the processing surface, or the like. The movement of the object, it is possible to eliminate the processing unevenness of the processing object caused by the improvement of the directivity of the neutral beam, and it is possible to perform uniform uniform processing over the entire processing object Becomes

Further, according to the present invention, when the neutral beam converted from the ion beam is passed through the ion repulsion electrode or the collimator to irradiate the object to be processed, the neutral beam is applied to the ion repulsion electrode or the collimator and to the processing surface. In contrast, a movement such as a rotation parallel to the object is given, so that the processing unevenness of the object to be processed caused by the improvement of the directivity of the neutral beam can be eliminated.
Similarly, uniform processing can be performed on the entire target object.

Further, according to the present invention, since the shutter for blocking the neutral beam is provided between the ion repulsion electrode and the object to be processed, the object to be processed can be replaced without stopping the operation of the surface treatment apparatus. Therefore, the plasma source, the ion beam extraction electrode, the ion repulsion electrode, and the like can be maintained in a constant state for each process.

Therefore, a stable ion beam and neutral beam can always be generated, and the processing conditions do not vary from one processing object to another. Since the sputtering amount of the shutter can be reduced as compared with the case where the ion beam is shut off, the inside of the apparatus can be kept clean.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a dry etching apparatus according to a first embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view illustrating a temperature control function of a workpiece provided in a holder.

FIG. 3 is a diagram for explaining the operation of the etching apparatus.

FIG. 4 is a schematic sectional view showing a dry etching apparatus according to a second embodiment of the present invention.

FIG. 5 is a diagram for explaining the operation of the dry etching apparatus.

FIG. 6 is a schematic sectional view showing a dry etching apparatus according to a third embodiment of the present invention.

FIG. 7 is an explanatory diagram showing an example of a voltage applied to each electrode when controlling the ion beam velocity.

FIG. 8 is a diagram showing a potential gradient on the Z axis in FIG. 7;

FIG. 9 is a diagram showing energy when the ion beam is decelerated by the velocity control electrode.

FIG. 10 is a graph showing the energy distribution of a neutral beam when the ion beam is decelerated.

FIG. 11 is a graph showing the energy distribution of a neutral beam when the ion beam is not decelerated.

FIG. 12 is a graph showing the energy distribution of a neutral beam when the ion beam is accelerated.

FIG. 13 is a schematic sectional view showing a dry etching apparatus according to a fourth embodiment of the present invention.

FIG. 14 is an energy phase diagram for explaining the principle of neutral beam excitation.

FIG. 15 is a diagram showing a comparison between an etching rate according to the prior art and an etching rate according to the present invention.

FIG. 16 is a schematic sectional view showing an example of a static magnetic field lens.

FIG. 17 is a schematic sectional view showing a dry etching apparatus of a sixth embodiment according to the present invention.

FIG. 18 is an explanatory view showing the operation of the holder in the sixth embodiment.

FIG. 19 is an explanatory view showing the operation of the holder in the seventh embodiment.

FIG. 20 is an explanatory view showing the operation of the holder in the eighth embodiment.

FIG. 21 is a schematic sectional view showing a main part of an etching apparatus according to a ninth embodiment of the present invention.

FIG. 22 is an explanatory view showing the operation of the ninth embodiment.

FIG. 23 schematically shows the features of the tenth embodiment,
7 AA sectional equivalent view

FIG. 24 is a partially enlarged sectional view showing a mechanism for transmitting a rotational driving force to the ion repulsion electrode.

FIG. 25 is a plan view of the transmission mechanism.

FIG. 26 is a schematic sectional view showing an etching apparatus of an eleventh embodiment according to the present invention.

FIG. 27 is an enlarged perspective view showing a shutter employed in the eleventh embodiment.

FIG. 28 is a schematic sectional view showing an etching apparatus according to a twelfth embodiment of the present invention.

FIG. 29 is an enlarged plan view showing a shutter employed in a twelfth embodiment;

FIG. 30 is a schematic sectional view showing an example of a conventional neutral beam etching apparatus.

FIG. 31 is a schematic sectional view showing another example of a conventional neutral beam etching apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Plasma chamber 12 ... Ion extraction electrode 14 ... Neutralization chamber 16 ... Treatment chamber 18 ... Waveguide 20 ... ECR electromagnet 22 ... Ion repulsion electrode 24 ... Vacuum exhaust pipe 26 ... Holder 28 ... First electrode 30 ... First 2 electrodes 32 ... speed control electrode 34 ... excitation device 36 ... static magnetic field lens 36A ... yoke 36B ... coil 38 ... collimator S ... substrate to be processed (object to be processed)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-29251 (JP, A) JP-A-54-107674 (JP, A) JP-A-1-120826 (JP, A) JP-A-3-112 155132 (JP, A) JP-A-62-108525 (JP, A) JP-A-64-89520 (JP, A) JP-A-63-157887 (JP, A) JP-A-5-129096 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01L 21/3065 C23F 4/02

Claims (23)

(57) [Claims] 1. A surface for converting an ion beam extracted from plasma into a neutral beam, passing the neutral beam through an ion repulsion electrode, and irradiating an object to be processed attached to a holder with the neutral beam. In the processing equipment, the ion beam is converted to a neutral beam in the space where the ion beam is converted to a neutral beam.
A surface treatment apparatus, wherein at least one of an electrostatic field lens and a static magnetic field lens for preventing divergence of a beam is provided in one or two or more lenses. (2)In claim 1, At least one of the electrostatic field lens and the static magnetic field lens
A surface treatment device, wherein two or more are disposed. 3. The surface treatment apparatus according to claim 1, wherein the holder is movable in at least one of a direction parallel and a direction perpendicular to the surface of the object. 4. The ion repelling electrode according to claim 1 , wherein the ion repelling electrode is a mesh-shaped ion repelling electrode.
Reference numeral denotes a collimator, wherein the ion repulsion electrode or the collimator is movable in a direction parallel to the surface of the object to be processed. 5. The surface treatment apparatus according to claim 1, wherein a shutter for blocking a neutral beam is provided between the ion repulsion electrode and the holder. 6. The method according to claim 3, wherein the movement of the holder in a direction parallel to the surface of the object is performed.
A surface treatment apparatus characterized by at least one of coaxial rotation, eccentric rotation, and linear movement. 7. The surface treatment apparatus according to claim 4, wherein the movement of the ion repulsion electrode or the collimator is at least one of coaxial rotation, eccentric rotation and linear movement. 8. The surface treatment apparatus according to claim 4, wherein the holder is movable in a direction parallel to the surface of the object. In any one of claims 9 claims 1 to 5, the surface treatment apparatus characterized in that a pumping means for exciting the neutral beam generating in the space to convert the ion beam into the neutral beam. In any one of claims 10] claims 1 to 5, the surface treatment apparatus characterized in that a temperature control means for controlling the temperature of the object to be processed. 11. An ion beam extracted from a plasma is converted into a neutral beam, and the neutral beam passes through an ion repulsion electrode and irradiates an object to be processed attached to a holder to process the surface thereof. In the surface treatment apparatus, apart from the ion repulsion electrode, at a position close to the ion repulsion electrode in a space for converting the ion beam into a neutral beam,
A surface treatment apparatus comprising a speed control electrode for accelerating and decelerating an ion beam. 12. An ion beam extracted from a plasma is converted into a neutral beam, and the neutral beam passes through an ion repulsion electrode and is irradiated on an object to be processed attached to a holder to process the surface thereof. In the surface treatment equipment, the ion beam is converted to a space where the ion beam is converted to a neutral beam.
At least one of an electrostatic field lens and a static magnetic field lens for preventing the divergence of the beam is provided, and at least one or more of the electrostatic field lens and the static magnetic field lens are provided. Separate from ion repulsion electrode
And a speed control electrode for accelerating and decelerating the ion beam. 13. A surface treatment method for converting an ion beam extracted from plasma into a neutral beam, passing the neutral beam through an ion repulsion electrode, irradiating an object to be treated, and treating the surface thereof. A surface treatment method characterized in that at least one of an electrostatic field lens and a static magnetic field lens is disposed in a space for converting a laser beam into a neutral beam, thereby preventing divergence of an ion beam. 14.In claim 13, At least one of the electrostatic field lens and the static magnetic field lens is 2 or more.
A surface treatment method characterized by being disposed above. 15. An ion beam extracted from a plasma is converted into a neutral beam, and the neutral beam is passed through an ion repulsion electrode and irradiated on a workpiece mounted on a holder to treat the surface thereof. In the surface treatment method, apart from the ion repulsion electrode , at a position close to the ion repulsion electrode in a space for converting an ion beam into a neutral beam ,
A surface treatment method comprising providing a velocity control electrode for accelerating and decelerating an ion beam, and reducing a high energy component of the neutral beam. 16. The method of claim 1 or 2, none of the electrostatic field lenses, and magnetostatic field lens, which prevents dispersion of the ion beam in the space, the minimum value in the axial direction distribution of the energy of the ion beam A surface treatment apparatus having a function of generating. 17. The method of claim 1 or 2, in the space, a surface treatment apparatus, characterized in that the ion beam is converted to a neutral beam by charge exchange reaction. 18. In any one of claims 1 to 5, by the target gas to perform charge exchange reaction with the ion beam to an excited state, characterized in that a pumping means for exciting the neutral beam to be converted And surface treatment equipment. 19. The method of claim 13 or 14, none of the electrostatic field lenses, and magnetostatic field lens, which prevents dispersion of the ion beam in the space, the minimum value in the axial direction distribution of the energy of the ion beam A surface treatment method characterized by generating. 20. The method of claim 1 9, in the space, the appropriate energy to produce a reaction to convert the ion beam into the neutral beam, surface treatment and adjusts the energy of the ion beam Method. 21. The method according to claim 13 , 14, 19, or 20 , wherein the ion beam is converted into a neutral beam by a charge exchange reaction in the space. 22. An ion beam extracted from the plasma is converted into a neutral beam in a neutralization chamber by a charge exchange reaction,
In a surface treatment method of treating a surface of an object to be treated with a neutral beam taken out of the neutralization chamber by passing through an ion repulsion electrode, at least one of an electrostatic field lens and a static magnetic field lens is provided in the neutralization chamber. A surface treatment method comprising disposing one or two or more ions to prevent divergence of an ion beam; 23. In claim 22, At least one of the electrostatic field lens and the static magnetic field lens
A surface treatment method, wherein two or more are provided.