JP2846890B2 - Surface treatment method and apparatus - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a surface treatment technique, and more particularly, to a technique effective when applied to a plasma etching technique used in a wafer processing step in a semiconductor device manufacturing process.

[Prior art] For example, in a plasma etching processing technique in a semiconductor wafer manufacturing process, the temperature of the semiconductor wafer rises due to ion incidence or plasma reaction heat, and the photoresist film is degraded or melted, which hinders the etching processing. You.

Such an adverse effect can be prevented, for example, by etching the semiconductor wafer while cooling it to a predetermined temperature by the sample stage. In this case, the semiconductor wafer is simply placed on the sample stage by its own weight. It is not enough to do so, and it is desired that the thermal contact between the sample stage and the semiconductor wafer be enhanced so that the temperature of the sample stage is efficiently transmitted to the semiconductor wafer.

Therefore, for example, as described in JP-A-56-48132, a technique of mechanically clamping a semiconductor wafer on a sample stage and introducing a gas having a high thermal conductivity between the semiconductor wafer and the sample stage. Or JP-B-57-44747, JP-A-63-569
As described in JP-A No. 20 and JP-A-63-2324, a technique has been proposed in which a semiconductor wafer is electrostatically attracted to a sample stage by an electrostatic attraction plate formed on the sample stage.

On the other hand, the semiconductor wafer which has been cooled to a predetermined temperature and etched by such an etching technique has a photoresist film or the like removed in a post-processing chamber.

In this case, in the related art, for example, a predetermined post-process is performed in the post-process chamber after the semiconductor wafer after the etching process is opened to the atmospheric pressure outside the process chamber and its cooling temperature is increased. In JP-A-63-56920, a wafer is placed on a tray and carried into a container, the tray and the wafer are electrostatically chucked, the wafer is etched, and then the wafer is placed on the tray and carried out of the container. However, there is no concept of fixing the tray on a sample table before the etching process.

[Problems to be Solved by the Invention] However, in the above-described plasma etching technology and the like including the electrostatic attraction means, the insulator constituting the electrostatic attraction means is liable to be deteriorated by foreign matter, plasma, or the like, Due to the deterioration of the insulator, a stable electrostatic attraction force cannot be obtained for a long period of time.

Further, in the devices described in JP-A-62-229947 and JP-A-63-2324, when replacing a deteriorated insulator or the like, an electrostatic suction plate is formed integrally with the sample table. Therefore, the entire sample stage must be replaced, and as a result,
Replacement work is complicated and time loss is large, and economic loss due to replacement part cost is large.

For this reason, in the above-mentioned etching technique, improvement of the etching processing technique of the semiconductor wafer by adoption of the electrostatic suction means and mass production are substantially hindered.

On the other hand, the semiconductor wafer which has been cooled and etched by such an etching technique is opened to the atmospheric pressure outside the processing chamber and its cooling temperature is raised to near room temperature outside the processing chamber. Post-processing has been performed.

For this reason, a time is required between the etching process and the post-process to return the cooling temperature of the semiconductor wafer to a temperature close to room temperature. As a result, a large time loss is caused and improvement in the throughput is prevented.

An object of the present invention is to provide a surface treatment technique that can improve a surface treatment technique such as a semiconductor wafer etching treatment technique.

The above and other objects and novel features of the present invention are as follows.
It will be apparent from the description of this specification and the accompanying drawings.

[Means for Solving the Problems] Of the inventions disclosed in the present application, the outline of a representative one will be briefly described as follows.

That is, one surface treatment apparatus of the present invention is provided with a plasma source for generating plasma for surface treating an object to be processed, a sample table, and provided on the sample table, and electrostatically adsorbs the object to be processed. An electrostatic attraction plate for causing the first refrigerant to flow between the workpiece and the electrostatic attraction plate;
Means for flowing a second refrigerant between the electrostatic chuck plate and the sample stage.

Another surface treatment apparatus of the present invention is provided with a plasma generation source for generating plasma for surface-treating an object to be processed, a sample table, and provided on the sample table, and detachable from the sample table. An electrostatic attraction plate for electrostatically attracting the object to be processed, means for flowing a coolant between the object to be processed and the electrostatic attraction plate, the electrostatic attraction plate and the sample stage And means for flowing a refrigerant between them.

Further, another surface treatment apparatus of the present invention includes a sample stage, a high-frequency power source for applying a high frequency to the sample stage for generating plasma for processing an object to be processed, and a static power source provided on the sample stage. An electro-adsorption plate, a DC power supply for applying DC power to the sample stage to adsorb the object to be processed to the electrostatic adsorption plate, and flowing a coolant between the object to be processed and the electrostatic adsorption plate. Means, and means for flowing a coolant between the electrostatic suction plate and the sample stage.

Further, the surface treatment method of the present invention is a step of placing an object to be processed on an electrostatic attraction plate on a sample stage, and causing the object to be processed to be electrostatically attracted to the electrostatic attraction plate, and Flowing a refrigerant between the electrostatic attraction plate and between the electrostatic attraction plate and the object to be processed, and plasma-treating the surface of the object to be processed.

[Action]

In the surface treatment method and apparatus of the present invention, the object to be processed is electrostatically attracted to the electrostatic attraction plate, and between the object to be processed and the electrostatic attraction plate, and between the electrostatic attraction plate and the sample stage. By flowing the refrigerant, the object to be processed is securely held in close contact by electrostatic adsorption, and the thermal contact between the object to be processed and the sample stage is strengthened. It is further strengthened by flowing a coolant between the workpiece and the electrostatic chuck plate and between the electrostatic chuck plate and the sample table, and the temperature rise of the workpiece can be suppressed efficiently and reliably, and the processing accuracy is improved. Can be improved.

Embodiment 1 FIG. 1 is a sectional view showing an etching mechanism of a surface treatment apparatus according to an embodiment of the present invention, FIG. 2 is a sectional view showing a post-treatment mechanism of the surface treatment apparatus, and FIG. FIGS. 4 (a) and 4 (b) are partial cross-sectional views of an object to be processed showing an etching process by an etching mechanism of the surface treatment apparatus, and FIG. FIG. 7 is a diagram for comparing a temperature rise of an object to be processed to be etched by the etching mechanism of the surface treatment apparatus of FIG. 1 and the etching mechanism of the conventional surface treatment apparatus.

The surface treatment apparatus of the present embodiment is an apparatus for etching a semiconductor wafer, and includes a loader mechanism 1 as shown in FIG.
An etching mechanism 2, a transport mechanism 3, a post-processing mechanism 4,
An unloader mechanism 5, the semiconductor wafer sent from the loader mechanism 1 is subjected to low-temperature etching by the etching mechanism 2, and subsequently transferred to the post-processing mechanism 4 by the transfer mechanism 3 for ashing; and
The structure is such that it is housed in the unloader mechanism 5 and integrated processing is performed.

As shown in FIG. 1, the etching mechanism 2 is a microwave plasma etching type etching mechanism. The etching chamber 7 is formed of quartz or the like and has a hemispherical upper portion.

A sample stage 8 having a horizontal upper surface is provided in the etching chamber 7 via an insulator 8c. A semiconductor wafer 6 (object to be processed) to be etched, that is, For example, a semiconductor wafer 6 having a photoresist film pattern applied to a surface of a polycrystalline Si film or the like is placed.

An exhaust pipe 9 connected to a not-shown exhaust mechanism or the like is connected to a side surface of the etching chamber 7 so that the inside of the etching chamber 7 is exhausted to a predetermined degree of vacuum.

The etching chamber 7 is connected to a gas introduction pipe 10 connected to a gas source (not shown) on a side surface thereof. For example, an etching gas such as SF ₆ or NF ₃ is introduced into the etching chamber 7. It is a structure to be introduced.

In this case, for example, the etching pressure in the etching processing chamber 7 is set to 0.2 to 3.0 Pa.

The sample stage 8 is connected to a high-frequency power supply 13 and a DC power supply 14 via a blocking capacitor 11 and a matching box 12.

A ground electrode 15 is arranged around the outer periphery of the sample stage 8 in the etching chamber 7, and a high frequency power is applied between the sample stage 8 and the ground electrode 15 from a high frequency power supply 13. For example, the high-frequency power is 30 to 200 W.

A plurality of play insertion holes 8a are formed in the sample table 8, and wafer push-up pins 16 are loosely inserted into the play insertion holes 8a via seal members 17 such as O-rings.

The wafer lifting pins 16 are raised and lowered by a wafer lifting mechanism 18, and the semiconductor wafer 6 is moved up and down above the sample table 8 by the lifting and lowering of the wafer lifting pins 16.

A gas introduction hole 8b is connected to the free insertion hole 8a of the sample table 8,
An inert gas such as He, Ne, or Ar, or N ₂ , O ₂ , or freon gas (trade name) is introduced into the back surface of the semiconductor wafer 6 through the gas introduction hole 8b, the free insertion hole 8a, and the like. 8 is cooled by the temperature controller 19 to a temperature of, for example, -170 ° C to -120 ° C.

The temperature of the sample stage 8 can be controlled precisely by the temperature controller 19 in the range of -200C to + 400C.

On the sample table 8 having such a structure, an electrostatic suction plate 20 (electrostatic suction means) is provided with fastening means such as insulating screws.
It can be replaced or detached by 21 or the like.

The electrostatic attraction plate 20 is formed of a conductor 20a having a large thermal conductivity and an insulator 20b covering the surface side of the conductor 20a, for example, the conductor 20a is made of Al, an Al alloy, or the like. Formed by a thin plate with a wall thickness of 1 mm to 20 mm, and
0b is a film thickness of 10 μm made of Al ₂ O ₃ , AlN, SiC, SiO ₂ , Si ₃ N ₄ or the like.
It is formed of a thin film of about 500 μm.

Then, the semiconductor wafer 6 to be etched is placed on the insulator 20b of the electrostatic attraction plate 20, and is electrostatically attracted to the sample stage 8 by the electrostatic attraction force. The structure is such that the thermal contact with the base member 8 is strengthened.

In the present embodiment, such thermal contact is caused by the fact that the cooling gas from the gas introduction hole 8b is applied between the electrostatic chucking plate 20 and the sample table 8 and between the electrostatic chucking plate 20 and the semiconductor wafer 6. It is structured to be strengthened by being poured in between.

In the electrostatic attraction plate 20, a loose insertion hole 20c (a hole for raising and lowering the transport means) for raising and lowering the push-up pin 16 is provided.
There are multiple establishments facing a.

A hemispherical upper portion of the etching processing chamber 7 is
The microwave radiated by a microwave oscillator 23 (for example, an applied microwave power of 1.0 to 2.0 kW) is housed inside one end of the waveguide 22 and is connected to the other end of the waveguide 22. Has been introduced.

Around the outer periphery of the etching processing chamber 7, a diverging magnetic field forming coil 24a and an ECR (ELectr
On Cyclotron Resonance coils 24b are provided, respectively, and the coils 24a and 24b form a magnetic field having a predetermined magnetic flux density above the sample table 8.

Next, in the etching processing apparatus of the present embodiment, the semiconductor wafer 6 subjected to the low-temperature etching processing by the etching mechanism 2 is transferred to the etching processing chamber
Is transferred to the post-processing mechanism 4 through a vacuum chamber (not shown) in the transfer mechanism 3.

The post-processing mechanism 4 is a post-processing mechanism of a microwave downstream ashing type. As shown in FIG. 2, a semiconductor wafer 6 which has been subjected to the etching processing in the etching processing chamber 7 is placed in a post-processing chamber 26 as shown in FIG. A horizontal sample stage 25 is arranged.

The sample stage 25 can be controlled to a temperature of, for example, −60 ° C. to 25 ° C.

Then, the semiconductor wafer 6 which has been cooled to a temperature of -170 ° C. to -120 ° C. in the etching processing chamber 7 is immediately opened without being released to the atmospheric pressure or the like after the processing. 3 post-processing chamber 26
The ashing process is performed while the temperature is returned to a temperature near room temperature outside the post-processing chamber 26 by the sample table 25 in the post-processing chamber 26.

Further, at the time of such an ashing process, a microwave radiated by a microwave oscillator 28 (for example, an applied microwave power of 1.0 to 2.0 KW) connected to the waveguide 27 is introduced into the post-processing chamber 26, CF ₄ + O ₂ or C
An ashing gas such as HF ₃ + O ₂ is introduced into a post-processing chamber 26 from a gas introduction pipe 29 to perform an ashing process on the semiconductor wafer 6 on the sample table 25.

The ashing pressure in the post-processing chamber 26 during the ashing process is set to a degree of vacuum of, for example, 100 to 300 Pa via an exhaust pipe (not shown).

Next, an etching method using the etching apparatus of the present embodiment will be described.

For example, as shown in FIG. 4 (a), a semiconductor wafer 6 having a gate oxide film 6b, a polycrystalline Si film 6c, and a photoresist film 6d formed on a Si substrate 6a is not shown from the loader chamber of the loader mechanism 1. The wafer is conveyed to the etching chamber 7 of the etching mechanism 2 by the conveying means and stopped at a predetermined position above the sample table 8.

The semiconductor wafer 6 stopped at a predetermined position above the sample table 8 is pushed up by the lifting of the push-up pins 16, and thereafter, the carrier is retracted outside the etching processing chamber 7 and the push-up pins 16 are lowered. The semiconductor wafer 6 is placed on the insulator 20b of the electrostatic attraction plate 20.

Next, the inside of the etching chamber 7 is evacuated through an exhaust pipe 9 to a predetermined degree of vacuum, and an etching gas such as SF ₆ is introduced into the etching chamber 7 via a gas introduction pipe 10.

The etching pressure in the etching processing chamber 7 is, for example,
0.2 to 3.0 Pa.

Next, the coils 24a and 24b are energized to form a magnetic field having a predetermined magnetic flux density above the sample table 8, and the microwave oscillator 23 is activated to introduce a microwave into the etching chamber 7.

Further, the high frequency power supply 13 is turned on, and a high frequency power for bias of, for example, 30 W to 200 W is applied between the sample table 8 and the ground electrode 15.

Further, the DC power supply 14 is turned on, and a DC power of, for example, 50 to 2000 V is applied to the sample table 8 so that the semiconductor wafer 6 is placed on the insulator
b, the sample is electrostatically attracted to the sample stage 8 and the temperature controller 1
9 is operated to introduce a cooling gas such as He into the back surface of the semiconductor wafer 6 through the gas introduction hole 8b and the free insertion holes 8a and 20c.
For example, the semiconductor wafer 6 is cooled to a temperature of -170C to 120C.

In this case, in this embodiment, the semiconductor wafer 6 is securely brought into close contact with the sample table 8 by the electrostatic attraction force of the electrostatic attraction plate 20, and the cooling gas such as He from the gas introduction hole 8b is electrostatically charged. The semiconductor wafer 6 is poured between the suction plate 20 and the sample table 8 and between the electrostatic suction plate 20 and the semiconductor wafer 6 to enhance the thermal contact between the sample table 8 and the semiconductor wafer 6. Cooled efficiently and reliably.

When a predetermined operation is performed in this manner, the etching gas is excited by the interaction between the electric field of the microwave and the magnetic field generated by the coils 24a and 24b, the charged particles are cyclotron-moved, and the energy causes the etching gas to become plasma. The polycrystalline Si film on the surface of the semiconductor wafer 6 due to an etching reaction between the excited etching species in the plasma and the surface of the semiconductor wafer 6 and the impact of ions incident from the plasma on the surface of the semiconductor wafer 6. 6c etching is performed.

During this etching process, the temperature of the semiconductor wafer 6 is raised by ion irradiation, reaction heat, or the like.

As shown in FIG. 5, for example, as shown in FIG. 5, etching without a cooling means using a cooling gas from the gas introduction holes 8b and an electrostatic attraction means using the electrostatic attraction plate 20 as shown in FIG. A semiconductor wafer that is etched by a mechanism (an etching mechanism that has no cooling means and the semiconductor wafer is placed on a sample stage only by its own weight).
In the semiconductor wafer 30b subjected to the etching process by the etching mechanism 30a or the etching mechanism having the cooling means but not having the electrostatic attraction means, the temperature is greatly increased.

However, the semiconductor wafer 6 to be etched by the etching mechanism 2 of this embodiment has a cooling unit and an electrostatic suction unit, that is, as described above, the semiconductor wafer 6 is Due to the electro-adsorption force, it is securely adhered to the sample table 8, and the cooling gas from the gas inlet holes flows between the electrostatic suction plate 20 and the sample table 8 and between the electrostatic suction plate 20 and the semiconductor wafer 6. As a result, the thermal contact between the sample stage 8 and the semiconductor wafer 6 is strengthened, so that the temperature of the semiconductor wafer 6 rises slightly as shown in FIG.

For this reason, in the present embodiment, it is possible to reliably prevent the photoresist film 6d from being altered or melted, and to improve the etching processing accuracy.

Further, when the temperature is high as in the case of the semiconductor wafers 30a and 30b which are etched by the etching mechanism having no cooling means or electrostatic suction means, the vapor pressure of an etching reaction product such as SiF ₄ becomes large. Therefore, a large amount of an etching gas such as SF ₆ is introduced into the etching chamber 7 from the beginning of etching, and an etching reaction product such as SiF ₄ is generated on the side surface of the crystalline Si film 6 c of the semiconductor wafer 6. The undercut of the polycrystalline Si film 6c must be prevented.

For this reason, the semiconductor wafer 30 that has been etched by an etching mechanism that does not have a cooling unit or an electrostatic attraction unit.
As shown by the two-dot chain line in FIG. 4 (b), a large amount of etching reaction products 30c such as SiF ₄ are generated on the side surfaces of the a and 30b when the etching is completed. Further, a large amount of the etching reaction product 30c is generated on the inner wall surface of the etching processing chamber.

On the other hand, in this embodiment, the semiconductor wafer 6 being etched by the cooling means and the electrostatic suction means is used.
Since the temperature rise of the etching reaction product is reduced and the vapor pressure of the etching reaction product is reduced, only a small amount of an etching gas such as SF ₆ is introduced into the etching processing chamber 7, and the polycrystalline Si
The undercut of the film to be etched such as the film 6c can be prevented, and as shown by the solid line in FIG. 4B, SiF ₄ or the like generated on the side surface of the semiconductor wafer 6 such as the crystalline Si film 6c at the end of the etching. Etching reaction product 6e and etching reaction product 6e generated on the inner wall surface of etching chamber 7
Can be reduced.

Therefore, the etching reaction product by the post-processing mechanism 4
The removal of 6e and the cleaning of the etching chamber 7 can be facilitated.

By the way, if the etching process is repeated many times in this manner, the etching mechanism 2 tends to deteriorate the insulator 20b of the electrostatic chucking plate 20 due to foreign matter, plasma, or the like. The stable electrostatic attraction force of the plate 20 cannot be obtained, and the thermal contact between the semiconductor wafer 6 and the sample table 8 cannot be enhanced.

Therefore, in order to obtain a stable electrostatic attraction force by the electrostatic attraction plate 20 and to strengthen the thermal contact between the semiconductor wafer 6 and the sample table 8, replacement work of consumable parts such as the insulator 20b is required. You.

In this case, in this embodiment, the electrostatic chucking plate 20 is configured to be exchangeably or detachably mounted on the sample table 8 by the fastening means 21 or the like.
Replacement of the whole is not required, and by replacing only the electrostatic attraction plate 20, a stable electrostatic attraction force can be obtained and thermal contact can be strengthened, thereby facilitating the replacement operation.
It is possible to prevent the time loss of the exchange work and the economical loss due to the exchange of the entire sample table 8.

Next, the semiconductor wafer 6 subjected to the etching process by the etching mechanism 2 is not opened to the outside atmospheric pressure by the transport means (not shown) in the vacuum chamber of the transport mechanism 3 having a predetermined degree of vacuum. 4 is transferred to the post-processing chamber 26 and is placed on the sample table 25 in the post-processing chamber 26 set near room temperature outside the post-processing chamber 26.

That is, for example, the semiconductor wafer 6
The sample is placed on a sample table 25 in a post-processing chamber 26 at 25 ° C. In the post-processing chamber 26, for example, an ashing pressure of 10
It is 0 Pa to 300 Pa.

Next, the microwave radiated by the microwave oscillator 28 (for example, applied microwave power of 1.0 to 2.0 kW) and an ashing gas such as CF ₄ + O ₂ or CHF ₃ + O ₂ from the gas introduction pipe 29 are supplied into the post-processing chamber 26. And an ashing process by a microwave downstream ashing method is performed to remove the photoresist film 6d and the etching reaction product 6e of the semiconductor wafer 6.

In this case, the vapor pressure of the SiF ₄ etching reaction product 6e generated in the polycrystalline Si film 6c of the semiconductor wafer 6 becomes −
It is around 1 Pa at 160 ° C, and changes sharply.

Therefore, the etching reaction product 6e of the SiF ₄ of the semiconductor wafer 6 is reliably and quickly sublimated and removed in the post-processing chamber 26.

Then, the semiconductor wafer 6 having been subjected to the predetermined post-processing in this way is transferred from the post-processing chamber 26 to the unloader chamber of the unloader mechanism 5 by the transfer means (not shown). Since the temperature in the processing chamber 26 is closer to the room temperature, the air can be transferred to the unloader chamber of the unloader mechanism 5 immediately after the completion of the post-processing and transported.

As described above, according to the present embodiment, the predetermined processing of the semiconductor wafer 6 from the loader chamber of the loader mechanism 1 to the unloader chamber of the unloader mechanism 5 can be performed without any time loss.

Here, in the above-described embodiment, the case where the film to be etched is the polycrystalline Si film 6c has been described. For example, when the film to be etched is an Al alloy film or the like, the processing is performed under the following conditions. Thereby, substantially the same effects as described above can be obtained.

That is, in the etching mechanism 2, Cl ₂ + BCl ₃ or Cl ₂ + BCl ₃ + CF ₄ (CH
F ₃ ), the etching pressure in the etching chamber 7 is set to 0.5 to 3.
0 Pa, the temperature of the sample stage 8 is 40 to 60 ° C., and in the post-processing mechanism 4, the temperature of the sample stage 25 is 150 to 200 ° C., and the other conditions are the polycrystalline Si film 6c described above. And the same as In this case, it is the etching reaction product 6e
Since the vapor pressure of AlCl ₃ is about 1 Pa at 60 ° C. and changes sharply, the etching reaction product 6e of AlCl ₃ is surely and quickly formed in the post-processing chamber 26 in the same manner as described above. Sublimated and removed.

Embodiment 2 FIG. 6 is a sectional view showing an etching mechanism 2 of a surface treatment apparatus according to another embodiment of the present invention.

In the etching apparatus as the surface treatment apparatus of the second embodiment, the etching mechanism 2 is a parallel plate electrode type plasma etching mechanism.

As shown in FIG. 6, a sample stage 8 also serving as a lower electrode is provided via an insulator 8c at the lower center side of the etching chamber 7 of the etching mechanism 2.

An upper electrode 31 is disposed on the upper central side of the etching processing chamber 7 so as to face and parallel to the sample table 8 via an insulator 31a, and has a potential of GND.

A gas introduction hole 31b is formed in the upper electrode 31, and a predetermined etching gas is introduced between the sample table 8 and the upper electrode 31 in the etching chamber 7 through the gas introduction hole 31b in a shower shape. I have.

The etching processing apparatus according to the second embodiment is substantially the same as the above-described first embodiment in other configurations.

Therefore, the same effect as in the first embodiment can be obtained in the etching apparatus of the second embodiment.

Embodiment 3 FIG. 7 is a sectional view showing an etching mechanism of a surface treatment apparatus according to another embodiment of the present invention.

In the etching apparatus as the surface processing apparatus according to the third embodiment, the electrostatic chucking means 20 of the etching mechanism 2 comprises an insulator 6f formed on the sample stage mounting surface side of the semiconductor wafer 6.
And a conductor 20a having high thermal conductivity formed on the sample stage 8
The semiconductor wafer 6 on which the insulator 20b is formed is placed on the conductor 20a, the DC power supply 14 is turned on, and DC power is applied to the sample table 8, whereby the semiconductor wafer 6 It is structured to be electrostatically attracted to the table 8 side.

In this case, the insulator 6f is formed by bonding an insulating film similar to that of the first embodiment, that is, an insulating film such as Al ₂ O ₃ having a thickness of 1 μm to 100 μm on the back surface of the semiconductor wafer 6.

The conductor 20a is formed of a thin plate similar to that of the first embodiment, that is, a thin plate made of Al or an Al alloy and having a thickness of 1 mm to 20 mm.
By means of 2, it is installed on the sample table 8 so as to be exchangeable or detachable.

In the method of etching the semiconductor wafer 6 by the etching mechanism 2 of the third embodiment, the semiconductor wafer 6 on which the insulator 6f is formed is placed on the conductor 20a of the sample stand 8 so that the insulator 6f and the conductor 20a come into contact with each other. After placing the DC power supply
Is turned on to apply DC power to the sample table 8 to electrostatically attract the semiconductor wafer 6 to the sample table 8.

Then, similarly to the first and second embodiments, the semiconductor wafer 6 is etched.

According to the method of etching the semiconductor wafer 6 by the electrostatic suction means 20, the insulator 6f
Is located in the etching chamber 7 only during the etching process, so that the insulator 20b as in the first and second embodiments is used.
There is no need to consider the reduction of the electrostatic attraction effect due to the deterioration of the device, and therefore, it is not necessary to replace the electrostatic attraction means.

As described above, the invention made by the inventor has been specifically described based on the embodiments. However, the present invention is not limited to the embodiments 1, 2, and 3, and can be variously modified without departing from the gist thereof. Needless to say,

For example, in Examples 1, 2, and 3, the surface treatment apparatus and the treatment method of the present invention are applied to the etching treatment apparatus and the treatment method, but the present invention is limited to such an etching treatment apparatus and the treatment method. Is not used, for example, plasma CVD equipment, sputtering equipment,
The present invention can be applied to a lamp annealing device for ion implantation and a predetermined treatment method using each of these devices.

Further, the film to be etched in Examples 1, 2, and 3 was:
It is a single-crystal Si film 6c or an Al alloy film. For example, it can be applied to a poly-Si film, silicide film, Si oxide film, Si nitride film, Al-Cu-Si film, etc. as the film to be etched. It is possible.

Further, in the first and second embodiments, the electrostatic suction plate 20 is configured to be exchangeably or detachably mounted on the sample table 8 by fastening means 21 such as insulating screws. For example, it is also possible to adopt a structure in which the electrostatic suction plate 20 is exchangeably or detachably mounted on the sample table 8 by clamping or the like.

In the first, second, and third embodiments, the semiconductor wafer 6 is moved up and down above the sample table 8 by raising and lowering the plurality of wafer push-up pins 16. Single wafer lifting pin 16 with mounting table formed
It is also possible to adopt a structure in which the semiconductor wafer 6 is moved up and down above the sample table 8 by raising and lowering. In the case of such a structure, for example, a stepped loose insertion hole 20c formed corresponding to the temporary mounting table for wafer and the push-up pin 16 is opened in the electrostatic suction plate 20.

[Effects of the Invention] Of the inventions disclosed in the present application, effects obtained by typical ones will be briefly described as follows.

That is, in the surface treatment method and apparatus of the present invention, the object to be processed is electrostatically attracted to the electrostatic attraction plate, and between the object to be processed and the electrostatic attraction plate, and between the electrostatic attraction plate and the sample table. The flow of the coolant between the substrates ensures that the object to be processed is tightly held by electrostatic attraction, thereby strengthening the thermal contact between the object and the sample table and the thermal contact between the object and the sample table. Is further strengthened by flowing a coolant between the object to be processed and the electrostatic adsorption plate, and between the electrostatic adsorption plate and the sample table, so that the temperature rise of the object to be processed can be suppressed efficiently and reliably, Processing accuracy can be improved.

As a result, if the present invention is applied to, for example, etching of a semiconductor wafer, the temperature rise of the semiconductor wafer is suppressed,
The etching accuracy can be improved, the etching reaction product can be reduced, and the removal of the etching reaction product and the cleaning can be facilitated.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an etching mechanism of a surface treatment apparatus according to an embodiment of the present invention, FIG. 2 is a sectional view showing a post-treatment mechanism of the surface treatment apparatus, and FIG. 4 (a) and 4 (b) are partial cross-sectional views of an object to be processed showing an etching process by an etching mechanism of the surface treatment apparatus, and FIG. 5 is a view of the surface treatment apparatus of the present invention. FIG. 6 is a diagram for comparing a temperature rise of an object to be processed which is etched by an etching mechanism and an etching mechanism of a conventional surface treatment apparatus. FIG. 6 is a diagram showing another embodiment of the present invention. FIG. 7 is a sectional view showing an etching mechanism of a surface treatment apparatus according to another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... Loader mechanism, 2 ... Etching mechanism, 3 ... Transport mechanism, 4 ... Post-processing mechanism, 5 ... Unloader mechanism, 6, 30
a, 30b: Semiconductor wafer (workpiece), 6a: Si substrate, 6
b: gate oxide film, 6c: polycrystalline Si film, 6e, 30c: etching reaction product, 7, etching chamber, 8, 25 ...
… Sample table, 8a… Free insertion hole, 8b, 31b …… Gas introduction hole, 8c…
... Insulator, 9 ... Exhaust pipe, 10 ... Gas inlet pipe, 11 ... Blocking condenser, 12 ... Matching box, 13
…… High frequency power supply, 14 …… DC power supply, 15 …… Ground electrode, 16
…… Wafer lifting pin, 17 …… Seal member, 18 …… Wafer lifting mechanism, 19 …… Temperature controller, 20 …… Electrostatic suction plate (electrostatic suction means), 20a …… Conductor, 6f, 20b… ... Insulator, 20c ... Free insertion hole (hole for raising / lowering the transporting means), 21,32 ... Fastening means, 22,
27 …… Waveguide, 23,28 …… Microwave oscillator, 24a, 24b…
... Coil, 26 ... Post-processing chamber, 29 ... Gas inlet pipe, 31 ...
Upper electrode, 31a ... insulator.

Continuation of the front page (56) References JP-A-63-194345 (JP, A) JP-A-63-67743 (JP, A) JP-A-1-200625 (JP, A)

Claims (10)

(57) [Claims] 1. A plasma source for generating plasma for surface-treating an object to be processed, a sample stage, and an electrostatic attraction plate provided on the sample stage for electrostatically attracting the object to be processed. Means for flowing a first refrigerant between the object to be processed and the electrostatic adsorption plate; and means for flowing a second refrigerant between the electrostatic adsorption plate and the sample stage. Characteristic surface treatment equipment. 2. The surface treatment apparatus according to claim 1, wherein the first refrigerant is a cooling gas. 3. The surface treatment apparatus according to claim 1, wherein the second refrigerant is a cooling gas. 4. A plasma generating source for generating plasma for surface-treating an object to be processed, a sample stage, and provided on the sample stage and detachably attached to the sample stage. An electrostatic attraction plate for electrostatic attraction, means for flowing a coolant between the object to be processed and the electrostatic attraction plate, means for flowing a coolant between the electrostatic attraction plate and the sample table, A surface treatment apparatus comprising: 5. The surface treatment apparatus according to claim 4, wherein said electrostatic suction plate is fixed to said sample table by screws or clamps. 6. A sample stage, a high-frequency power source for applying a high frequency to the sample stage for generating plasma for processing an object to be processed, an electrostatic attraction plate provided on the sample stage, A DC power supply for applying DC power to a table to cause the electrostatic suction plate to adsorb the object to be processed; a means for flowing a refrigerant between the object to be processed and the electrostatic suction plate; A surface treatment apparatus comprising: means for flowing a coolant between a plate and the sample stage. 7. The apparatus according to claim 6, wherein the electrostatic attraction plate is formed of a conductive film and an insulating film provided on a surface of the conductive film on the side of the object to be processed. Surface treatment equipment. 8. The insulating film is not formed on the surface of the conductor film on the side of the sample stage.
The surface treatment apparatus as described in the above. 9. A step of placing an object to be processed on an electrostatic attraction plate on a sample stage, and causing the object to be processed to be electrostatically attracted to the electrostatic attraction plate, wherein the sample stage and the electrostatic attraction plate And flowing a refrigerant between the electrostatic attraction plate and the object to be processed, and plasma-treating the surface of the object to be processed. 10. The plasma is generated by applying a high frequency to the sample stage, and the electrostatic suction plate includes:
The surface treatment method according to claim 9, wherein the object is electrostatically attracted by applying DC power to the sample stage.