JP3301408B2 - Particle removing apparatus and method of removing particles in semiconductor manufacturing apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a particle removing apparatus and a particle removing method for a semiconductor manufacturing apparatus, and more particularly to a particle removing apparatus for a semiconductor manufacturing apparatus which prevents particles generated during a process from falling onto a wafer. And a method for removing particles.

[0002]

2. Description of the Related Art Particles generated in an LSI manufacturing process, particularly in a process using plasma, are a major factor in lowering the yield and the operating rate of an apparatus. Particles are generated when reaction products attached to the process apparatus are peeled off or reaction products grow in plasma. In order to prevent such particles from dropping on the substrate, Japanese Patent Application Laid-Open No. 5-29272 and Japanese Patent Application Laid-Open No.
As described in Japanese Patent Application Publication No. 3 (1993), an apparatus has been proposed in which a cover for covering a substrate after a process is mounted. FIG.
FIG. 9A is a diagram showing a conventional plasma etching apparatus. In FIG. 9, reference numeral 2100 denotes a processing chamber, in which an upper processing electrode 2200 and a lower processing electrode 2300 are provided. The upper electrode 2200 for processing is grounded, and the lower electrode 2300 for processing is
400 are connected.

The insulator 1 is provided on the lower electrode 2300.
Electrostatic chuck electrode 270 insulated by 900
0 is provided to the electrostatic chuck electrode 2700.
The semiconductor substrate 3000 is fixed by applying a voltage from 600. The processing chamber 2100 is provided with a gas inlet 3100 and a gas outlet 3200. Further, a cover 3600 is provided so that particles do not adhere to the semiconductor substrate 3000.

FIG. 9 shows a general operation cycle of a device in a plasma etching process in a semiconductor manufacturing process.
It is shown in (b). This represents a cycle for processing one substrate. When the substrate 3000 is transferred into the processing chamber 2100 from the transfer port 3800, the process gas is introduced into the introduction port 31.
When the pressure in the processing chamber 2100 reaches a specified value, a high frequency voltage is applied from the power supply 2400 to generate plasma and etch the substrate 3000. At the same time, the substrate 3000 is fixed by the electrostatic chuck. After the completion of the etching, the high-frequency voltage, the supply of the process gas, and the electrostatic chuck are simultaneously stopped. After a few seconds, an inert gas that does not contribute to the etching is supplied as a purge gas for a certain period of time for the purpose of quickly discharging the process gas. The processed substrate 3000 is transferred from the transfer port 3800 to the processing chamber 21.
It is transported outside 00.

[0005] In the above-described conventional apparatus, a cover 3600 is provided on the substrate 3000 in order to prevent particles from adhering to the substrate 3000. In the semiconductor manufacturing process, it has been found that the timing at which particles fall on the substrate is closely related to the operating state of the semiconductor manufacturing apparatus. In other words, the above-described conventional device does not consider the timing of covering the substrate 3000 at all, and has a serious disadvantage that particles cannot be sufficiently prevented from adhering to the substrate.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to improve the above-mentioned drawbacks of the prior art, and in particular, to control a cover provided on a substrate in a timely manner in accordance with the processing state of the substrate to thereby generate plasma. An object of the present invention is to provide a novel particle removing apparatus and a method for removing particles in a semiconductor manufacturing apparatus which prevent particles generated in a semiconductor device used from adhering to a substrate. Another object of the present invention is to provide a particle removing apparatus for a novel semiconductor manufacturing apparatus that prevents particles from adhering to a substrate without using a cover or the like by utilizing the feature that particles are positively charged. And a method for removing particles.

[0007]

SUMMARY OF THE INVENTION The present invention basically employs the following technical configuration to achieve the above object. That is, the first aspect of the particle removal apparatus of the semiconductor manufacturing apparatus according to the present invention is to process a substrate in the processing chamber by applying a high-frequency voltage between the upper electrode and the lower electrode to convert the processing chamber into plasma, In a semiconductor manufacturing apparatus provided with a cover that covers the substrate and covering the substrate by closing the cover to prevent particles in a processing chamber from adhering to the substrate, a drive timing of the cover is controlled. 1
The control means controls the cover from the open state to the closed state immediately before stopping the application of the high-frequency voltage, and the timing for controlling the cover from the closed state to the open state is when the processing is completed. The substrate is transported out of the processing chamber
Immediately after

[0008]

According to a second aspect, the timing for controlling the cover from the closed state to the open state is immediately before the application of the high-frequency voltage.
In a preferred embodiment, a second control means for applying a potential to the cover and controlling a timing for applying the potential to the cover is provided. Characterized by controlling to apply a potential to the cover for seconds,

A fourth aspect is characterized in that the potential is applied at least until immediately before the introduction of the purge gas, and a fifth aspect is that the potential is applied to a substrate which has been processed. Is applied until it is transported outside the processing chamber. In a sixth aspect, the potential is equal to or the same as the sign of the self-bias potential appearing on the lower electrode of the processing electrode. The absolute value is a potential higher than the self-bias potential, and the seventh aspect is that the potential is the same as the potential of the lower electrode of the processing electrode. It is assumed that.

[0011]

[0012]

[0013]

[0014]

[0015]

[0016]

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

Further , the semiconductor manufacturing apparatus according to the present invention
The aspect of the method for removing a tickle includes an etching processing chamber, a pair of processing electrodes including an upper electrode and a lower electrode installed in the processing chamber, and a susceptor for fixing a substrate to be processed on the lower electrode, In a semiconductor manufacturing apparatus in which a process gas is introduced into the etching processing chamber and a predetermined voltage is applied to the processing electrode to generate a plasma and process the substrate on the susceptor, a gas exhaust port of the processing chamber is electrically conductive. By applying a negative voltage to the exhaust port, the charged particles are guided toward the gas exhaust port, and at the same time, the etching gas in the processing chamber is exhausted.

[0025]

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A particle removing apparatus of a semiconductor manufacturing apparatus according to the present invention processes a substrate in a processing chamber by applying a high-frequency voltage between an upper electrode and a lower electrode to convert the processing chamber into plasma. Providing a cover that covers the substrate, and controlling the drive timing of the cover in a semiconductor manufacturing apparatus that covers the substrate by closing the cover and prevents particles in a processing chamber from adhering to the substrate. A first control unit, wherein the control unit controls the cover from an open state to a closed state immediately before stopping the application of the high-frequency voltage; The cover is controlled from the closed state to the open state in synchronization with the transport operation of the transported substrate transport device. Therefore, the cover is driven just before the particles are generated to cover the substrate, so that the particles are effectively prevented from adhering to the substrate. Further, by applying an appropriate potential to the cover, the cover has a dust collecting action, so that the particles can be more effectively prevented from adhering to the substrate.

Next, another embodiment of the present invention will be described. FIG. 21 shows a photograph in which the behavior of particles in plasma is captured in a schematic diagram of the apparatus. The right end of this figure corresponds to the vicinity of the center of the process equipment,
The left end corresponds to the vicinity of the wall of the process device. Particles are trapped in the sheath region near the upper electrode in FIG. 21 and, at the moment when the plasma is cut off, feel the potential of the afterglow plasma, and fly near the upper electrode toward the outer wall. It can be seen that near the center of the plasma, it falls downward along the outside of the plasma, and near the lower electrode, ie, the wafer, it flies toward the wafer by a self-bias voltage having a negative potential.
From these results, the particles are positively charged,
Utilizing this, a method of electrostatically removing particles is the basis of the present invention.

Next, FIG. 9B shows an example of the relationship between the number of particles generated during the operation of the etching apparatus and the operating state of the apparatus at that time. The apparatus shown in FIG. 9A is a conventional etching apparatus provided with a parallel plate type processing electrode. FIG. 9B shows a cycle for processing one substrate. When the substrate is transferred into the processing chamber from the transfer port, a process gas is supplied, and when the pressure in the processing chamber reaches a specified value, a high-frequency voltage is applied to generate plasma and etch the substrate. At this time, the substrate is fixed to the susceptor on the lower processing electrode. After the etching, the high frequency voltage, the process gas, and the electrostatic attraction of the substrate are simultaneously stopped. After a few seconds, an inert gas not contributing to the etching is supplied as a purge gas for a certain period of time for the purpose of quickly discharging the process gas, so that the pressure in the processing chamber increases. The substrate after the processing is transferred out of the processing chamber through the transfer port. In the figure, the number of particles P represented by an ellipse is obtained by irradiating a laser beam into the processing chamber of the etching apparatus to irradiate the space above the substrate, photographing the scattered light from the particles crossing the laser light with a CCD camera, and simultaneously etching This is a result obtained by capturing a signal indicating the operation state of the apparatus, and is an integrated value when 25 substrates are processed.

From FIG. 9B, the generation of the particles P during the etching clearly corresponds to the operation state of the apparatus. That is, almost no particles are generated during the etching, but many particles are generated at a time at the end of the etching, and the frequency of generation of the particles is high when the purge gas is introduced. When the image in which the scattered light from the particles was captured was examined in detail, it was found that the tracks of the particles at the end of the etching tended toward the substrate, and tended toward the exhaust port when the purge gas was introduced. From the above, the particles floating during the etching fall because the high-frequency power supply was stopped at the end of the etching,
It is considered that because of the small viscous flow of the process gas, the process gas flies toward a substrate that has not been completely neutralized. However, several seconds after the end of the etching, the purge gas is introduced, and the particles are considered to head to the exhaust port together with the purge gas.

According to the present invention, a cover is provided on a wafer when the voltage is stopped, or a negative potential is applied to a conductive plate or grid by utilizing the fact that particles in a processing chamber are positively charged. Thus, the generated particles are moved toward the trap or the exhaust port, and are prevented from reaching the substrate.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific examples of a semiconductor manufacturing apparatus and a control method thereof according to the present invention will be described in detail with reference to the drawings. FIG. 1A is a diagram showing the structure of a specific example of a semiconductor manufacturing apparatus according to the present invention. In these figures, a high-frequency voltage is applied between an upper electrode 2200 and a lower electrode 2300 to process a chamber 2100. By converting the inside into a plasma, the substrate 300
0 and a cover 3 for covering the substrate 3000
600, and the cover 3600 is closed to cover the substrate 3000, and particles
Semiconductor manufacturing equipment 4000 which is prevented from adhering to
At

A first control means 200 for controlling the drive timing of the cover 3600 is provided.
0 indicates the semiconductor manufacturing apparatus 4000 that controls the cover 3600 from the open state to the closed state just before stopping the application of the high-frequency voltage, and the transfer of the substrate transfer apparatus 1600 provided in the semiconductor manufacturing apparatus 4000. The semiconductor manufacturing apparatus 4000 is characterized in that the cover 3600 is controlled from the closed state to the open state in synchronization with the operation.

FIG. 1B is a block diagram showing the overall structure of the plasma etching apparatus according to the present invention.
600, a driving device 400, an etching gas supply device 1200 for supplying an etching gas into the processing chamber, a purge gas supply device 1300 for supplying a purge gas for discharging the etching gas, and a vacuum adjusting device for adjusting the degree of vacuum in the processing chamber. 1400, a gas discharge device 1500 for discharging gas in a processing chamber, a substrate transfer device 1600 for transferring a substrate, a high-frequency power supply device 240 for plasma generation
0, DC power supply 2 for electrostatic chuck for fixing substrate
The controller 600 is controlled by a control device 1700 such as a microcomputer or a sequencer, so that a predetermined process is performed on the substrate 3000. The first control means 20
0, the second control means 300 is included in the control device 1700. As described above, the semiconductor manufacturing apparatus used in the present invention has the same configuration as the conventional configuration except for the control of the cover 3600.

FIG. 9B shows the relationship between the number of particles P generated during plasma etching and the operating state of the etching apparatus. In the figure, the number of particles P represented by ellipses is obtained by irradiating a laser beam into the processing chamber 2100 of the etching apparatus, irradiating the space above the substrate 3000, and photographing the scattered light of the particles P crossing the laser beam with a CCD camera. At the same time, this is a result obtained by taking in a signal indicating the operating state of the etching apparatus, and is an integrated value when 25 substrates are processed. The generation of the particles P during the etching clearly corresponds to the operation state of the apparatus. That is,
Almost no particles are generated during etching, but many particles are generated at the end of etching,
Further, particles are frequently generated when the purge gas is introduced.

On the other hand, when the image in which the scattered light from the particles was captured was examined in detail, the trace of the particles at the end of etching tended toward the substrate, and tended toward the exhaust port when the purge gas was introduced. From the above, it is considered that particles that floated during etching fall due to the stop of the high-frequency power supply at the end of etching, and fly toward a substrate that has not been completely neutralized because the viscous flow of the process gas is small. Can be But,
A few seconds after the end of the etching, a purge gas is introduced, and the particles are considered to head to an exhaust port together with the purge gas.

The following specific examples have been invented based on the above findings. The following specific examples 1 to 16 are RF plasma CVD apparatuses, R
The present invention can be commonly applied to an F plasma etching apparatus and an RF plasma sputtering apparatus. Here, an RF plasma etching apparatus will be described unless otherwise specified, but the same applies to other RF processing apparatuses.

(First Specific Example) FIG. 3A shows a flow of a cover operation timing according to a first specific example of the present invention. The cover 3600 covering the substrate 3000 is closed at t1 immediately before stopping the high frequency voltage, and the particles falling toward the substrate 3000 at the moment when the high frequency voltage stops are received by the cover 3600. Cover 36
00 is closed during the introduction of the purge gas with a high particle generation frequency, and after the introduction of the purge gas is stopped, the cover is opened at t2 immediately before the processed substrate is transported out of the processing chamber 2100. As described above, while many particles P are falling on the substrate, the cover 3600 is in the closed state, so that the cover 3600 covers the substrate 3000 reliably and prevents the particles P from adhering. The shape of the cover may be a single plate or a plurality of blades such as a camera shutter. Also,
The semiconductor manufacturing apparatus to which the present invention is applied is not limited to the plasma etching apparatus as in the conventional example, but can be applied to an apparatus that processes using plasma such as a plasma CVD apparatus. In addition,
The timing of opening the cover may be t21 immediately after the processed substrate is transported out of the processing chamber 2100 as shown in FIG.

(Second Specific Example) FIG. 4 shows a flow of a cover operation timing according to a second specific example of the present invention. At time t1 immediately before stopping the high frequency voltage, the cover 3600 covering the substrate 3000 is closed, and the particles P falling toward the substrate at the moment when the high frequency voltage is stopped.
Is received by the cover 3600. Substrate 3 after processing
After the 000 is transferred out of the processing chamber 2100, the cover is opened at t3 immediately before the next substrate is transferred into the processing chamber. In this way, it is possible to prevent particles falling by operating the cover from adhering to the substrate.

(Third Specific Example) FIG. 5 shows a flow of cover operation timing according to a third specific example of the present invention. Immediately before the application of the high-frequency voltage, the cover covering the substrate is opened at t4, and immediately before the high-frequency voltage stops, at t1.
Close the cover. When the etching process is not performed, the cover 3600 is closed so that the upper processing electrode 2200 is closed.
And the particles falling and falling from the inner wall of the processing chamber 2100 are received by the cover to prevent the particles from adhering to the substrate. In addition, in addition to the above configuration, a detecting means for detecting that the cover 3600 has been closed is provided, and the high-frequency power supply 240
You may be comprised so that 0 may be turned off.

(Fourth Specific Example) FIG. 6A shows a flow of cover potential change timing according to a fourth specific example of the present invention. In addition to the first to third embodiments of the present invention, a potential is further applied to the cover 3600 from a time t5 immediately before stopping the application of the high-frequency voltage to a time t6 of several seconds from the start of the introduction of the purge gas. Even after the application of the high-frequency voltage is stopped, the particles fall toward the substrate charged with the residual charge of the electrostatic chuck. Therefore, the potential of the cover is equal to the self-bias potential of the lower electrode 2300, or the sign is one. It is preferable to select a value whose absolute value is larger than the self-bias potential. Particles generated immediately after stopping the application of the high-frequency voltage drop toward the cover 3600 and are attracted. Particles generated after the introduction of the purge gas are flown by the purge gas and fall toward the exhaust port 2200, and do not adhere to the substrate. Regarding the material of the cover 3600, the processing chamber 210
A material having the same conductivity as the inner wall, for example, an aluminum alloy may be used, and the surface of the metal electrode may be covered with aluminum oxide or silicon oxide in order to reduce particles generated. As shown in FIG. 6B, a configuration may be adopted in which a potential is applied at t61 immediately before the purge gas is introduced.

(Fifth Specific Example) FIG. 7 shows a flow of a cover potential change timing according to a fifth specific example of the present invention. In the second and third specific examples (FIGS. 4 and 5) of the present invention, a potential is applied to the cover from t7 immediately before stopping the application of the high-frequency voltage to time t8 when the unloading of the processed substrate from the processing chamber is completed. . Whether the potential of the cover is equal to the self-bias potential of the lower electrode 2300,
It is preferable to select a value whose sign matches and whose absolute value is larger than the self-bias potential. Particles generated from immediately after the application of the high-frequency voltage is stopped until the transfer port is opened are collected on the cover and do not adhere to the substrate.

(Sixth Embodiment) FIG. 8 shows a flow of a cover potential change timing according to a sixth embodiment of the present invention. In the second and third specific examples (FIGS. 4 and 5) of the present invention, a potential is applied to the cover from when the cover starts to be closed until the cover is opened. By applying the same potential to the cover 3600 and the lower processing electrode 2300 during the application of the high-frequency voltage, no discharge occurs between the substrate 3000 and the cover 3600, thereby preventing damage to the substrate and generation of particles between the cover and the substrate. can do. Then, after the application of the high-frequency voltage is stopped, the potential of the cover is equal to the self-bias potential, or the potential coincides with the sign and a potential whose absolute value is larger than the self-bias potential is applied. Note that this specific example may be applied to the first specific example.

(Seventh Specific Example) FIG. 10 shows one typical operating state of an etching apparatus generally used in a semiconductor manufacturing plant. Etching is performed by introducing a highly reactive process gas such as chlorine into the processing chamber from the upper electrode / gas blow-out plate facing the substrate, and applying a voltage between the electrodes when the pressure reaches a certain level, thereby converting the process gas into plasma. You. When the etching is completed, the application of the high-frequency voltage and the introduction of the process gas are simultaneously stopped, and after a few seconds, a halogen gas or the like having low reactivity is introduced as a purge gas. In the etching apparatus according to the seventh embodiment of the present invention shown in FIG. 11, the supply of the process gas is stopped when the etching is completed. At this time, it is known that the particles are positively charged, and by using this, the conductive particle removing electrode 1 provided between the upper electrode 2200 and the lower electrode 2300 in the processing chamber 2100 is used.
By applying a negative potential to 1, particles are forcibly removed. As for the shape of the particle removing electrode 11, any existing shape such as a plate or a lattice may be used as long as the process is not affected. Many particles that fall at the moment when the high-frequency voltage stops are trapped by the particle removing electrode 11, and are prevented from reaching the substrate 3000. Note that the power supply control means 420 of the negative power supply 410 for applying a negative potential to the electrode 11 may be provided in synchronization with the end of the etching.

(Eighth Specific Example) FIG. 12 shows an etching apparatus incorporating a function of trapping particles using a deposition shield. In a semiconductor manufacturing apparatus, a shield plate 12 for preventing deposits generated during processing from adhering to a chamber wall is often used. The shield plate 12 is provided with the processing electrode 2.
200, 2300 and the side wall of the processing chamber 2100, the deposit is intentionally deposited on the shield plate 12, and the shield plate 12 is replaced to reduce the number of times of cleaning in the chamber. It is something that can be done. In many cases, the deposition shield 12 is made of a conductive metal or the like, and the deposition shield 12 is electrically insulated from the chamber. Apply a negative potential.
Many positively charged particles falling at the moment when the high frequency voltage stops are attracted by the potential potential of the shield plate 12 having a negative potential, and finally trapped on the wall surface of the shield plate 12. , Substrate 3
000 is prevented.

(Ninth Specific Example) FIG. 13 shows an etching apparatus incorporating a function of trapping particles using a grid 13 having conductivity. That is, the grid 13 is connected to the processing electrode 2200,
The grid 13 is provided between the chamber 2300 and the side wall of the processing chamber 2100 so as to be electrically insulated from the chamber. At the end of the etching, the supply of the process gas is stopped, and a negative potential is applied to the grid 13. A large number of positively charged particles falling at the moment when the high frequency voltage stops are attracted by the potential potential of the grid 13 having a negative potential, are finally trapped by the grid 13, and are prevented from reaching the substrate. You.

(Tenth Specific Example) FIG. 14 shows that a gas exhaust port 14 provided at the lower part of a processing chamber is formed of a conductive member, for example, a metal, and this gas exhaust port 14 is electrically insulated. This is an etching apparatus in which particles are guided to an exhaust port, and are further forcibly exhausted so that the particles do not fall onto a substrate. That is, when the supply of the process gas is stopped at the end of the etching, a negative potential is given to the exhaust port 14, whereby a large number of positively charged particles falling at the moment when the high frequency voltage stops have a negative potential. The gas is drawn by the potential potential of the exhaust port 14 and finally exhausted, and is prevented from reaching the substrate.

(Eleventh Specific Example) FIG. 15 shows an etching apparatus in which a grid 13 having conductivity is provided near a gas exhaust port 14 and particles are trapped by the grid 13. That is, the exhaust port 1 is electrically insulated from the grid 13 with the chamber.
4, the supply of the process gas is stopped at the end of the etching, and a negative potential is applied to the grid 13. Many positively charged particles falling at the moment when the high-frequency voltage stops are attracted by the potential potential of the grid 13 having a negative potential, and finally the
3 or exhausted from the exhaust port 14,
The arrival at the substrate is prevented.

(Twelfth Specific Example) FIG. 16 shows a twelfth specific example. A grid 13 having conductivity is provided between the upper electrode 2200 and the lower electrode 2300, and is kept electrically floating. By doing so, during the process, that is, during the discharge, the grid 13 follows the potential of the plasma and becomes in a floating state. When a negative potential is applied to the grid 13 at the end of the process, the particles are attracted by the potential potential having the negative potential, thereby preventing the particles from reaching the substrate. Then, in this state, the semiconductor substrate 3
000.

(Thirteenth Specific Example) FIG. 17 shows a thirteenth specific example. In this specific example, a sufficiently large plasma PZ is generated for the semiconductor substrate 3000. Since the plasma PZ is generated in accordance with the diameters of the upper electrode 2200 and the lower electrode 2300, in the case of FIG. 17, the plasma is generated far outside the substrate 3000. As described above, by causing the plasma PZ to protrude more than the substrate 3000, particles can be prevented from falling along the peripheral portion of the plasma PZ and falling onto the substrate 3000.

(Fourteenth Specific Example) FIG. 18 shows a fourteenth specific example. In this specific example, a donut-shaped electrode 15 is arranged on the lower electrode 2300 so as to surround the substrate 3000, and a negative voltage having an absolute value larger than the self-bias voltage is applied to the electrode 15. In this case, the applied voltage may be a DC voltage. The voltage is applied when the process is completed and the plasma power is turned off. Also, a cathode electrode, that is, a lower electrode 2300
Apply a constant negative bias to the voltage applied to
The same fluctuation as the self-bias voltage may be performed. By doing so, particles having a positive charge are transferred to the electrode 1
5 to prevent the particles from falling onto the substrate 3000.

(Fifteenth Specific Example) FIG. 19 shows a fifteenth specific example. In this specific example, a laser device for monitoring the generation of particles is introduced into the processing chamber 2100. Here, the place through which the laser beam passes is the anode electrode, that is, the upper electrode 2.
In the vicinity of the upper electrode 2200, particles trapped in the vicinity of the plasma sheath can be found at an early stage. After detecting the generation of particles, the electrode 1
5, a particle is collected by applying a negative voltage to the substrate 30.
It is possible to prevent the particles from falling on the top surface.

(Sixteenth Specific Example) FIG. 20 shows a sixteenth specific example. In this specific example, the particle removing electrode 15 is provided between the upper electrode 2200 and the lower electrode 2300, the gate valve 17 is provided on the side wall of the processing chamber near the particle removing electrode 15, and a vacuum pump or the like is further provided outside the gate valve 17. Connect the exhaust system.
Then, a negative voltage is applied to the electrode 15. When the process is completed and the voltage application to the cathode electrode, that is, the lower electrode 2300 is stopped, a negative voltage is applied to the electrode 15. Thereby, the particles are drawn toward the gate valve 17. At this time, by simultaneously opening the gate valve 17 and exhausting the particles, the particles can be prevented from falling onto the substrate 3000. In FIG. 19, reference numeral 450 denotes third control means for applying a negative voltage to the particle removing electrode 15 based on the detection result of the generation of particles in the processing chamber. The above specific examples 1 to 16 are all RF plasma CVD apparatuses using a high-frequency power supply,
The present invention can be commonly applied to an RF plasma etching apparatus and an RF plasma sputtering apparatus. On the other hand, the following specific examples 17 to 32 can be commonly applied to a DC plasma CVD apparatus, a DC plasma etching apparatus, and a DC plasma sputtering apparatus using a DC power supply.

(Seventeenth Embodiment) FIG. 22 shows a flow of a cover operation timing according to a seventeenth embodiment of the present invention. Immediately before the DC voltage is stopped, the cover 3600 covering the substrate 3000 is closed at t11, and the particles falling toward the substrate 3000 at the moment when the DC voltage is stopped are received by the cover 3600. The cover 3600 is closed during the introduction of the purge gas with a high particle generation frequency, and after the introduction of the purge gas is stopped, the cover is opened at t12 immediately before the processed substrate is transported out of the processing chamber 2100. As described above, while many particles P are falling on the substrate, the cover 3600 is in the closed state, so that the cover 3600 covers the substrate 3000 reliably and prevents the particles P from adhering. The shape of the cover may be a single plate or a plurality of blades such as a camera shutter.

(Eighteenth Embodiment) FIG. 23 shows a flow of cover operation timing according to an eighteenth embodiment of the present invention. T11 immediately before stopping the DC voltage
Then, the cover 3600 covering the substrate 3000 is closed, and the particles P falling toward the substrate at the moment when the DC voltage stops are received by the cover 3600. After the processed substrate 3000 is transported out of the processing chamber 2100, the cover is opened at t13 immediately before the next substrate is transported into the processing chamber. In this way, it is possible to prevent particles falling by operating the cover from adhering to the substrate.

(Nineteenth Specific Example) FIG. 24 shows a flow of cover operation timing according to a nineteenth specific example of the present invention. Immediately before applying DC voltage t14
The cover covering the substrate is opened at the time t before the DC voltage stops.
Close the cover at 11. When the etching process has not been performed, the cover 3600 is closed, so that the upper processing electrode 22 is closed.
00 and particles falling off the inner wall of the processing chamber 2100 are received by the cover to prevent the particles from adhering to the substrate. In addition, in addition to the above configuration, a detecting means for detecting that the cover 3600 has been closed is provided, and the DC power supply 24
00 may be turned off.

(Twentieth Specific Example) FIG. 25 shows a flow of a cover potential change timing according to a twentieth specific example of the present invention. Seventeenth to nineteenth aspects of the invention
In addition to the above specific examples, a potential is further applied to the cover 3600 from t15 immediately before stopping the application of the DC voltage to time t16 of several seconds from the start of the introduction of the purge gas. Particles generated immediately after stopping the application of the DC voltage fall toward the cover 3600 and are attracted to the cover. Particles generated after the introduction of the purge gas flow into the purge gas and fall toward the exhaust port 3200, and do not adhere to the substrate. Regarding the material of the cover 3600,
The same conductive material as the inner wall of the processing chamber 2100, for example,
An aluminum alloy may be used, and the surface of the metal electrode may be covered with aluminum oxide or silicon oxide to reduce generated particles.

(Twenty-First Example) FIG. 26 shows a flow of cover potential change timing according to a twenty-first example of the present invention. In the eighteenth and nineteenth specific examples (FIGS. 23 and 24) of the present invention, the potential is applied to the cover from t17 immediately before stopping the application of the DC voltage to time t18 when the removal of the processed substrate from the processing chamber is completed. give. Particles generated from immediately after the application of the DC voltage is stopped until the transfer port is opened are collected on the cover and do not adhere to the substrate.

(Twenty-Second Specific Example) FIG. 27 shows a flow of cover potential change timing according to a twenty-second specific example of the present invention. In the eighteenth and nineteenth specific examples (FIGS. 23 and 24) of the present invention, a potential is applied to the cover from when the cover starts to be closed until the cover is opened. During the application of the DC voltage, the cover 3600 and the lower processing electrode 230
By setting 0 to the same potential, the substrate 3000 and the cover 360 are set.
No discharge occurs during the period of 0, and damage to the substrate and generation of particles between the cover and the substrate can be prevented. After the application of the DC voltage is stopped, a negative potential is applied to the cover. Note that this specific example may be applied to the seventeenth specific example.

(Twenty-third Specific Example) FIG. 28 is a schematic view showing a cross-sectional structure of a DC plasma processing apparatus generally used in a semiconductor manufacturing plant. FIG.
In the DC plasma processing apparatus of the twenty-third specific example shown in FIG. 7, it is known that particles are positively charged at the end of the DC plasma process, and this is used to apply a negative potential to the particle removing electrode 11. Removes particles. Particle removal electrode 1
Regarding the shape 1, any existing shape may be used as long as it does not affect the DC plasma process. A large number of particles falling at the moment when the DC voltage stops are trapped by the particle removing electrode 11, and the substrate 3
000 is prevented.

(Twenty-fourth Specific Example) FIG. 30 shows a DC plasma processing apparatus configured to trap particles using a deposition shield. That is, a deposition shield 12 is often used to prevent deposits generated during processing from adhering to the chamber walls. By intentionally depositing deposits on the deposition shield and replacing the deposition shield 12, the number of times of cleaning the inside of the chamber can be reduced. The deposition shield 12 is often made of a conductive metal or the like. The deposition shield 12 is electrically insulated from the chamber, and a negative potential is applied to the deposition shield 12 at the end of the DC plasma process. Many positively charged particles falling at the moment when the DC voltage stops are attracted by the potential potential of the deposition shield 12 having a negative potential, and finally trapped on the wall surface of the deposition shield 12, and Reaching 3000 is prevented.

(Twenty-Fifth Example) FIG. 31 shows a DC plasma processing apparatus configured to trap particles using a grid 13 having conductivity. That is, the grid 13 is installed so as to be electrically insulated from the chamber, and a negative potential is applied to the grid 13 at the end of the etching. Many positively charged particles that fall at the moment when the DC voltage stops are attracted by the potential potential of the grid 13 having a negative potential, are finally trapped by the grid 13, and are prevented from reaching the substrate 3000. Is done.

(Twenty-Sixth Specific Example) FIG. 32 shows a DC plasma process apparatus in which particles are forcibly exhausted by setting the gas exhaust port 14 to be electrically insulated from the chamber. That is, in this particle removing apparatus, a large number of positively charged particles falling at the moment when the DC voltage is stopped are discharged by applying a negative potential to the exhaust port 14 at the end of the DC plasma process. Mouth 14
And finally evacuated to prevent it from reaching the substrate 3000.

(Twenty-Seventh Specific Example) FIG. 33 shows a DC plasma processing apparatus in which a grid 13 having conductivity is provided in the vicinity of a gas exhaust port 14 so as to trap particles. That is, in this particle removing apparatus, the grid 13 is installed in front of the exhaust port 14 so as to be electrically insulated from the chamber, and a negative potential is applied to the grid 13 at the end of the DC plasma process. A large number of positively charged particles that fall at the moment when the DC voltage stops are converted to a grid 1 having a negative potential.
3 and is finally trapped by the lid 13 or exhausted from the exhaust port 14 to prevent the substrate 3000 from reaching.

(Twenty-eighth Specific Example) FIG. 34 shows a twenty-eighth specific example. The grid 13 is provided between the upper electrode 2200 and the lower electrode 2300, and is kept electrically floating. By doing so, during the process, that is, during the discharge, the grid 13 follows the potential of the plasma and becomes in a floating state. At the end of the process, connect the grid 13 to the power supply 4400,
Discharge is caused between the grid 13 and the upper electrode 2200. At this time, the power supply 4400 is not connected to the lower electrode 2300. In this state, the semiconductor substrate 3000 is transported. By doing so, the particles do not fall while being trapped between the upper electrode 2200 and the grid 13.
Also, even if it falls, it flies to the periphery of the plasma due to the potential of the plasma and falls to the periphery of the substrate, and does not fall on the substrate.

FIG. 35 shows a twenty-ninth example. In this specific example, a sufficiently large plasma PZ is applied to the semiconductor substrate 3000.
Generate. Since the plasma PZ is generated according to the diameters of the upper electrode 2200 and the lower electrode 2300, FIG.
In this case, the plasma is generated to a far outside of the substrate 3000. As described above, by making the plasma PZ protrude more than the substrate 3000,
The particles fall along the peripheral portion of the plasma and can prevent the particles from falling onto the substrate 3000.

(Thirtieth Specific Example) FIG. 36 shows a thirtieth specific example. In this specific example, a donut-shaped electrode 15 is arranged around the substrate 3000, and a negative voltage is applied to the electrode 15. Further, the timing of applying the negative voltage is performed when the plasma power is turned off after the process is completed. With this configuration, particles having a positive charge are guided to the electrode 15 and the substrate 300
It can be prevented from dropping onto zero.

(Thirty-First Specific Example) FIG. 37 shows a thirty-first specific example. In this specific example, laser light for detecting particles is introduced into the processing chamber 2100. Here, the place through which the laser beam passes is near the upper electrode 2200, and thus, particles trapped near the upper electrode 2200 can be found early. Then, after detecting the generation of the particles, a negative voltage is applied to the electrode 15 to collect the particles and prevent the particles from falling onto the substrate 3000.

(32nd Specific Example) FIG. 38 shows a 32nd specific example. In this specific example, the gate valve 17 is installed outside the upper electrode 2200, and an exhaust system such as a vacuum pump is connected outside the gate valve 17. An electrode 15 is provided before the gate valve 17 so that a negative voltage can be applied. When the process is completed and the voltage application to the lower electrode 2300 is stopped, a negative voltage is applied to the electrode 15. Therefore, the particles are drawn toward the gate valve 17. At this time, by simultaneously opening the gate valve 17 and exhausting the particles, the particles can be prevented from falling onto the substrate 3000.

[0069]

As described above, the present invention can reduce particles adhering to a substrate. Further, since the invention is based on the charged state of the particles, it is possible to efficiently prevent the adhesion of the particles.

[Brief description of the drawings]

FIG. 1 is a block diagram of a particle removing apparatus of a semiconductor manufacturing apparatus according to the present invention.

FIG. 2 is a diagram showing a configuration of a particle removing apparatus according to the present invention.

FIG. 3 is a diagram illustrating the operation timing of the board cover according to the first specific example of the present invention.

FIG. 4 is a diagram showing operation timings of a board cover according to a second specific example of the present invention.

FIG. 5 is a diagram showing operation timings of a board cover according to a third specific example of the present invention.

FIG. 6 is a diagram showing a potential application timing of a substrate cover according to a fourth specific example of the present invention.

FIG. 7 is a diagram showing a potential application timing of a substrate cover according to a fifth specific example of the present invention.

FIG. 8 is a diagram showing a potential application timing of a substrate cover according to a sixth specific example of the present invention.

9A is a diagram illustrating a configuration of a conventional etching apparatus, and FIG. 9B is a diagram illustrating a relationship between an operating state of the etching apparatus and the number of generated particles.

FIG. 10 is a diagram showing operation timing of a general etching apparatus.

FIG. 11 is a diagram showing a configuration of a seventh specific example of the present invention.

FIG. 12 is a diagram showing an eighth example of the present invention.

FIG. 13 is a diagram showing a ninth specific example of the present invention.

FIG. 14 is a diagram showing a tenth specific example of the present invention.

FIG. 15 is a diagram showing an eleventh example of the present invention.

FIG. 16 is a diagram showing a twelfth example of the present invention.

FIG. 17 is a diagram showing a thirteenth specific example of the present invention.

FIG. 18 is a diagram showing a fourteenth specific example of the present invention.

FIG. 19 is a diagram showing a fifteenth specific example of the present invention.

FIG. 20 is a diagram showing a sixteenth example of the present invention.

FIG. 21 is a diagram and a photograph showing movement of particles in plasma.

FIG. 22 is a diagram showing the operation timing of the board cover according to the seventeenth example of the present invention.

FIG. 23 is a diagram showing the operation timing of the board cover according to the eighteenth example of the present invention.

FIG. 24 is a diagram showing the operation timing of the board cover according to the nineteenth example of the present invention.

FIG. 25 is a diagram showing a potential application timing of a substrate cover according to a twentieth example of the present invention.

FIG. 26 is a diagram showing a potential application timing of a substrate cover according to a twenty-first example of the present invention.

FIG. 27 is a diagram showing a potential application timing of a substrate cover according to a twenty-second example of the present invention.

FIG. 28 is a cross-sectional view showing a structure of a general DC plasma processing apparatus.

FIG. 29 is a diagram showing a twenty-third specific example of the present invention.

FIG. 30 is a diagram showing a twenty-fourth example of the present invention.

FIG. 31 is a diagram showing a twenty-fifth specific example of the present invention.

FIG. 32 is a diagram showing a twenty-sixth example of the present invention.

FIG. 33 is a diagram showing a twenty-seventh example of the present invention.

FIG. 34 is a diagram showing a twenty-eighth specific example of the present invention.

FIG. 35 is a diagram showing a twenty-ninth specific example of the present invention.

FIG. 36 is a diagram showing a thirtieth specific example of the present invention.

FIG. 37 is a diagram showing a thirty-first example of the present invention.

FIG. 38 is a diagram showing a 32nd example of the present invention;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Particle removal electrode 12 Deposition prevention shield 13 Grid 14 Exhaust port 15 Electrode 16 Laser device 17 Gate valve 200 First control means 300 Second control means 410 Negative power supply 420 Power supply control means 450 Third control means 3100 Etching gas introduction Port 1200 Etching gas supply device 1300 Purge gas supply device 1400 Vacuum degree adjustment device 1500 Gas discharge device 1600 Substrate transfer device 1700 Control device 1900 Insulator 2000 Gas blowout plate 2100 Processing chamber 2200 Processing upper electrode 2300 Processing lower electrode 2400 High frequency power supply 2600 DC power supply for substrate adsorption 2700 Electrostatic chuck electrode 3000 Semiconductor substrate 3100 Inlet for etching gas 3200 Gas outlet 3600 Cover 3800 Substrate transport port 4000 Conductor manufacturing apparatus 4400 direct-current power supply P particles PZ plasma

Continuation of the front page (56) References JP-A-5-29272 (JP, A) JP-A-7-153740 (JP, A) JP-A-7-58033 (JP, A) JP-A-10-284471 (JP) JP-A-5-275350 (JP, A) JP-A-11-121435 (JP, A) JP-A-11-121437 (JP, A) JP-A-6-124902 (JP, A) 5-114583 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/3065 H01L 21/31

Claims (8)

(57) [Claims] A process for applying a high-frequency voltage between an upper electrode and a lower electrode to generate plasma in the processing chamber to process a substrate in the processing chamber and to provide a cover for covering the substrate;
In a semiconductor manufacturing apparatus in which the cover is closed to cover the substrate to prevent particles in the processing chamber from adhering to the substrate, a first control unit for controlling the drive timing of the cover is provided. The control means controls the cover from the open state to the closed state just before stopping the application of the high-frequency voltage, and controls the cover from the closed state to the open state at a time when the processed substrate is transferred out of the processing chamber. A particle removing apparatus for a semiconductor manufacturing apparatus, wherein the apparatus is immediately after the removal. 2. The particle removing apparatus according to claim 1, wherein the timing of controlling the cover from the closed state to the open state is immediately before the application of the high-frequency voltage. 3. A second control means for applying a potential to the cover and controlling a timing of applying the potential to the cover, wherein the control means starts the introduction of the purge gas at least immediately before stopping the application of the high-frequency voltage. 3. The particle removing apparatus of a semiconductor manufacturing apparatus according to claim 1, wherein control is performed so that a potential is applied to the cover for a few seconds thereafter. 4. The apparatus according to claim 3, wherein the potential is applied at least until immediately before the purge gas is introduced.
A particle removing apparatus for a semiconductor manufacturing apparatus according to the above. 5. The particle removing apparatus according to claim 3, wherein the potential is applied until the processed substrate is transported out of the processing chamber. 6. The potential according to claim 3, wherein the potential is equal to or has the same sign as a self-bias potential appearing at a lower electrode of the processing electrode, and has an absolute value larger than the self-bias potential. A particle removing apparatus for a semiconductor manufacturing apparatus according to any one of the above. 7. The particle removing apparatus according to claim 3, wherein the potential is equal to a potential of a lower electrode of the processing electrode. 8. An etching processing chamber and an etching processing chamber.
A pair of processing electrodes consisting of an upper electrode and a lower electrode placed
And a susceptor for fixing a substrate to be processed on the lower electrode
A process gas into the etching chamber.
Introduced, by applying a predetermined voltage to the processing electrode,
Semiconductor for processing a substrate on the susceptor by turning into plasma
In the manufacturing apparatus, the gas exhaust port of the processing chamber is formed of a conductive member,
By applying a negative voltage to the exhaust port, charged particles
At the same time as guiding the gas toward the gas exhaust port,
Semiconductor gas characterized by exhausting an etching gas
A method for removing particles from a manufacturing apparatus.