JP3438496B2 - Wafer stage, manufacturing method thereof and dry etching 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 wafer stage mainly used for manufacturing a semiconductor device, and more particularly to a wafer stage suitably used for a process of heating a wafer to a high temperature to perform a plasma treatment, and a wafer stage of the same. The present invention relates to a manufacturing method and a dry etching apparatus equipped with this wafer stage.

[0002]

2. Description of the Related Art In the manufacture of semiconductor devices, there are many processes such as plasma etching and plasma CVD for subjecting a wafer to plasma treatment. In such a plasma process, particularly in plasma etching and the like, etching from room temperature to low temperature is being adopted in order to improve the processing accuracy, and it is recognized that wafer temperature control is important.

By the way, in recent years, along with the progress of the multi-layer wiring technology in LSI, there is a demand for a new material such as Cu to be used as a wiring material for reducing the resistance, and high density plasma CVD is used for the gap fill technology. Requirements such as adoption are becoming more and more important, and not only in the process of performing plasma treatment at room temperature to low temperature as described above, but also in the process of performing plasma treatment at high temperature, its importance is increasing. There is.

However, in such plasma treatment,
There is a large heat input from the plasma to the wafer due to ion bombardment in the etching process, irradiation with high-density plasma in the gap fill CVD process, etc., for example, the temperature of the wafer is about 40 ° C. to 100 ° C. or more compared to before plasma generation. It may rise. Therefore, even in the process of heating the wafer by the wafer stage that holds the wafer and performing plasma processing at a high temperature, it is important to suppress the influence of heat input from the plasma to the wafer and control the wafer to a preset temperature. .

[0005]

However, conventionally, such wafer temperature control is not sufficiently performed at a high temperature, and it is natural that the temperature rise of the above-mentioned degree occurs during the process treatment. In reality, the temperature of the wafer stage is set to a low level in advance in anticipation of such a temperature rise, and the process conditions are set. However, if the process is performed in anticipation of a rise in temperature in this way, there are many improvements such as the process time being extended and the throughput being reduced, and the reproducibility and controllability of the process being reduced due to a large temperature change. There are issues to be solved.

As one of means for solving such a problem, it is possible to mount an electrostatic chuck on a wafer stage heated at high temperature. However, mounting the electrostatic chuck on the wafer stage has a big problem of how to bond the heated wafer stage and the dielectric in the electrostatic chuck. It has been impeding practical application. That is, in the wafer stage of heating specification, it is a necessary condition that heat can be efficiently transferred to the wafer when the wafer is sucked and fixed on the stage via the electrostatic chuck. Therefore, it is necessary that the wafer stage and the electrostatic chuck are bonded in a state of good heat conduction.

By the way, as a material of a wafer stage in a process apparatus such as etching or CVD, aluminum (Al) is used because of its thermal conductivity and easiness of processing.
Is often used. However, Al has a large linear expansion coefficient of about 23 × 10 ⁻⁶ / ° C., and ceramics generally used as a dielectric for an electrostatic chuck are destroyed by high temperature heating due to the difference in linear expansion coefficient with Al. It will be done.

Therefore, at present, the electrostatic chuck is fixed to the wafer stage by a method such as screwing and used. However, with such a structure, when the electrostatic chuck and the wafer stage are used under reduced pressure in the plasma processing apparatus, the bonding interface between the electrostatic chuck and the wafer stage is vacuum-insulated, and the wafer is efficiently transferred to the wafer through the electrostatic chuck. The heat cannot be transferred well, and as a result, the wafer receives heat from the plasma, and the temperature rises above the set value.

The present invention has been made in view of the above circumstances.
The purpose of this is to provide a wafer stage equipped with an electrostatic chuck and capable of heating a wafer at a high temperature by eliminating the inconvenience at the time of high temperature heating, a manufacturing method thereof, and a dry etching including the wafer stage. To provide a device.

[0010]

[Means for Solving the Problems] Claim 1 in the present invention
The wafer stage described above is a wafer stage in which a temperature control jacket is provided with an electrostatic chuck function, and the temperature control jacket has therein a heater and a temperature medium pipe connected to a temperature control means, and The upper surface is made of aluminum or an aluminum alloy integrated with a thermal buffer layer, and the thermal buffer layer is formed by pouring aluminum or an aluminum alloy into the holes of the plate-shaped porous Al ₂ O _3. Are formed in a composite manner, on the thermal buffer layer of the temperature control jacket, a dielectric film is formed by a thermal spraying method, by using the temperature control jacket as an electrode, The temperature control jacket and the dielectric film function as an electrostatic chuck to solve the above problems.

According to this wafer stage, the heat buffer layer is formed by pouring aluminum or aluminum alloy into the holes of the plate-like porous Al ₂ O ₃ and compounding them. Linear expansion coefficient is Al ₂ O
It is an intermediate value between ₃ and aluminum, and therefore
It has a linear expansion coefficient between a metal having a large linear expansion coefficient and an insulating material having a small linear expansion coefficient. Therefore, when a dielectric film made of an insulating material is heated by a temperature control jacket made of aluminum or an aluminum alloy, it is thermally conducted via the thermal buffer layer without being directly conducted. It is possible to prevent the dielectric film from cracking or peeling due to the difference in the linear expansion coefficient. In addition, since the dielectric film is formed on the temperature control jacket by the thermal spraying method, the temperature control jacket and the dielectric film are more integrated, and the stress between them can be relaxed and the temperature control can be achieved. The heat conduction from the jacket to the dielectric film becomes quick.

In the method of manufacturing a wafer stage according to a third aspect of the present invention, a plate-shaped porous Al is formed at the bottom of the mold.
₂ O ₃ is provided, and a heater and a heating medium pipe are provided thereon, and molten aluminum or molten aluminum alloy is poured into the mold in this state to form a temperature control jacket by a high pressure casting method, and then the temperature control is performed. The means for solving the above problems is to form a dielectric film by forming an insulating material on the surface of the jacket on the side of the porous Al ₂ O ₃ by a thermal spraying method.

According to this wafer stage manufacturing method,
Porous Al provided on the bottom of the mold₂O ₃Molten aluminum
High-pressure casting by pouring aluminum or molten aluminum alloy
The temperature control jacket is formed by the method
Porous Al in the tone jacket₂O₃Side is almost the front side
It will be exposed. In addition, this porous Al₂O₃To
Is aluminum or aluminum alloy in its hole
Is filled with this porous Al₂O₃Part
Al₂O₃And aluminum or aluminum alloy
It is a composite material with intermediate properties of
The number is also an intermediate value between these. Therefore, this
Insulating material is deposited on the surface of porous alumina by spraying method
Made of an insulating material by forming a dielectric film
The dielectric film has the above-mentioned porous alumina portion close to its linear expansion coefficient.
Aluminum that becomes the body of the temperature control jacket through the minute
Indirect connection to aluminum or aluminum alloy
Become. Therefore, in the obtained wafer stage
Is the coefficient of linear expansion between the dielectric film and the temperature control jacket.
The dielectric film may be cracked or peeled due to the difference in
And can be suppressed.

According to a fifth aspect of the present invention, the dry etching apparatus is provided with the wafer stage according to the first aspect, which is a means for solving the above-mentioned problems.

According to this dry etching apparatus, since it is equipped with the wafer stage, there is no inconvenience such as cracking of the dielectric film on the wafer stage even when the high temperature etching process is performed, and the wafer stage is also provided. The wafer electrostatically attracted onto the wafer is heated to a desired temperature, for example, 20
It becomes possible to stabilize at a high temperature such as 0 to 250 ° C.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.
FIG. 1 is a diagram showing an embodiment of a wafer stage of the present invention, in which reference numeral 1 is a wafer stage. The wafer stage 1 has an electrostatic chuck function, and has a dielectric film 4 having an electrostatic chuck function formed on a disk-shaped temperature control jacket 2 with a thermal spraying base layer 3 interposed therebetween.

The temperature control jacket 2 is made of aluminum and is formed by a high-pressure casting method. The heater 5 and the heating medium pipe 6 are embedded in the temperature control jacket 2 and a thermal buffer made of a composite aluminum material is provided on the upper surface thereof. It is integrated with layer 7. The heater 5 is composed of a large-sized and large-capacity sheathed heater corresponding to the area (bottom area) of the temperature control jacket 2, and is connected to a power source via a wiring (not shown). The temperature medium pipe 6 is made of a metal having a high thermal conductivity such as Al or Cu connected to the temperature control means described later, and the temperature medium supplied from the temperature control means is caused to flow into the temperature control jacket 2 to control the temperature. This is for causing heat exchange with the tone jacket 2.

The thermal buffer layer 7 is a plate-shaped porous material A called a fiberboard, as will be described later.
Aluminum having a thickness of about 10 mm was formed by pouring aluminum into the holes of l ₂ O ₃ to form a composite. In this example, the porosity is 5 as porous Al ₂ O _3.
By selecting 0%, its linear expansion coefficient
Linear expansion coefficient of metal aluminum (about 23 × 10 ^-6 / ° C)
It is adjusted to about half, and the thermal conductivity is 150 [W / m
.K] and the thermal conductivity of metallic aluminum is 240 [W /
[m · K].

Further, the temperature control jacket 2 having such a structure.
A thermal spraying base layer 3 and a dielectric film 4 are formed in this order on the thermal buffer layer 7. The thermal sprayed base layer 3 is formed of Ni-5% Al in this example, and the dielectric film 4 is formed of Al ₂ O ₃ which is an insulating material and TiO ₂
Is formed by adding an appropriate amount. The thermal spraying base layer 3 and the dielectric film 4 are both formed on the temperature control jacket 2 by a thermal spraying method as described later, and the thermal spraying base layer 3 has a thickness of about 0.4 mm and a dielectric The body film 4 is formed to have a thickness of about 0.2 mm. Here, the thermal spraying base layer 3 is formed of a material having a linear expansion coefficient intermediate between the linear expansion coefficient of the thermal buffer layer 7 and the linear expansion coefficient of the dielectric film 4. In this example, Previous
As noted, Ni-5% Al is used.

Under such a structure, the wafer stage 1
Through the wiring (not shown) to the temperature control jacket 2
Since the C voltage is applied and the temperature control jacket 2 is used as an electrode, the temperature control jacket 2 and the dielectric film 4 function as an electrostatic chuck as described later. A pusher pin (not shown) for pushing up the wafer placed and held on the dielectric film 4 is embedded in the wafer stage, and the pusher pin is attached to the surface of the dielectric 4 on the pusher pin. A projecting / withdrawing mechanism (not shown) that projects or is buried under the surface is connected.

In order to manufacture the wafer stage 1 having such a structure, first, as shown in FIG. 2, a plate-like porous Al ₂ O ₃ 31 is placed on the bottom of the mold 30, and the heater 5 is placed thereon.
Put. Subsequently, an Al plate 32 is placed on this as a spacer, and the heating medium pipe 6 is placed thereon. Then, the Al plate 32 is preheated in this state, and then the molten aluminum 33 is poured into the mold 30. And
The temperature control jacket 2 is obtained by a high pressure casting method in which a high pressure of about 1 ton / cm ² is applied in the mold 30.

When the temperature control jacket 2 is formed in this way, the porous Al ₂ O ₃ 31 is filled with molten aluminum 33 in its pores, and this is cooled and solidified, whereby porous Al ₂ O _{3 is formed.} 31 is a composite aluminum material. The thermal buffer layer 7 is formed of this composite aluminum material. In addition,
By selecting the porosity of the porous Al ₂ O ₃ as described above, the physical properties of the obtained composite aluminum material (thermal buffer layer 7), such as the linear expansion coefficient and the thermal conductivity, are adjusted to desired values. be able to.

Next, as shown in FIG. 1, Ni-5% Al is thermally sprayed on the surface of the obtained temperature control jacket 2 on the porous Al ₂ O ₃ 31 side, that is, the upper surface of the thermal buffer layer 7, and the thermal spraying is performed. The base layer 3 is formed. After that, A is formed on the thermal spraying base layer 3.
l ₂ O ₃ is sprayed to form the dielectric film 4, and the wafer stage 1 is obtained. Here, when the dielectric film 4 is formed, an appropriate amount of TiO ₂ is added to Al ₂ O ₃ so that the dielectric film 4 functions as a dielectric of the electrostatic chuck, and the deposition resistivity thereof is 10 ^11. It was adjusted to the order of Ω / cm ² . When the dielectric film 4 is higher than the range of the specific resistance value, the attraction force becomes too strong when used as an electrostatic chuck,
This is because the wafer may be difficult to remove, and if it is lower than the range of the specific resistance value, the resistance becomes further lower when the wafer stage 1 is used at a high temperature. This is because an electric current may be generated at the interface with 4.

According to such a manufacturing method, by forming the temperature control jacket 2 by the high pressure casting method, the porous Al
The ₂ O ₃ 31 holes in the molten aluminum 33 can be sufficiently filled, thereby regard to physical properties such as mechanical strength, of course coefficient of linear expansion and thermal conductivity, the porous Al ₂
A composite aluminum material having a value close to the value estimated from the porosity of O ₃ 31 by the amount ratio of Al ₂ O ₃ and aluminum is obtained in a state of being integrated with the surface layer portion of the temperature control jacket 2. .

Therefore, in the wafer stage 1 thus obtained, the coefficient of linear expansion of the thermal buffer layer 7 in the temperature control jacket 2 is an intermediate value between Al ₂ O ₃ and aluminum. Naturally, it has a coefficient of linear expansion between the dielectric film 4 made of Al ₂ O ₃ and the temperature control jacket 2 made mainly of aluminum. Moreover,
Since the thermal spraying base layer 3 is formed of a material having a linear expansion coefficient between the thermal buffer layer 7 and the dielectric film 4, the dielectric film 4 is not heated by the temperature control jacket 2 at a high temperature. , The thermal buffer layer 7 and the thermal spraying base layer 3 are not directly thermally conducted, but are thermally conducted through the material whose linear expansion coefficient is gradually reduced.
It is possible to prevent the dielectric film 4 from cracking or peeling due to the difference in linear expansion coefficient between the main material of aluminum and the dielectric film 4 of Al ₂ O ₃ . Further, since the dielectric film 4 is formed on the temperature control jacket 2 by the thermal spraying method, the temperature control jacket 2 and the dielectric film 4 are more integrated, and the stress between them can be relaxed. At the same time, the heat conduction from the temperature adjustment jacket 2 to the dielectric film 4 becomes quick, and the temperature of the wafer held and fixed on the dielectric film 4 can be quickly controlled as described later.

In the above example, the temperature control jacket 2 is made of aluminum as the main material, but it may be made of aluminum alloy as the main material in consideration of the coefficient of linear expansion and thermal conductivity. Further, when the material of the dielectric film 4 is appropriately selected and the difference in linear expansion coefficient or thermal conductivity between the dielectric film 4 and the temperature control jacket 2 is reduced, the sprayed base layer 3 is eliminated,
The dielectric film 4 may be directly sprayed on the thermal buffer layer 7 of the temperature control jacket 2.

Next, as an embodiment of the dry etching apparatus of the present invention, a dry etching apparatus equipped with the wafer stage 1 shown in FIG. 1 will be described with reference to FIG.
In FIG. 3, reference numeral 10 is a dry etching apparatus (hereinafter,
This etching device 10 is configured to include a helicon wave plasma generation source having RF antennas installed at two locations and a stage movable in the vertical direction. And the RF antenna 1 provided above the diffusion chamber 11.
2 and 12, an RF antenna 13 installed in a loop on the top plate 11a of the diffusion chamber 11, and a cusp magnetic field provided outside the lower part of the diffusion chamber 11 for suppressing disappearance of electrons on the wall. And a multi-pole magnet 14 that operates.

The RF antennas 12 and 12 are provided around the outside of a bell jar 15 formed of a cylindrical quartz tube having a diameter of 350 mm formed in the upper part of the diffusion chamber 11, and M = 1 mode plasma is generated. It has a standing antenna shape. A solenoid coil assembly 16 including an inner peripheral coil and an outer peripheral coil is arranged outside the RF antennas 12, 12. The inner peripheral coil of the solenoid coil assembly 16 contributes to the propagation of the helicon wave, and the outer peripheral coil contributes to the transportation of the generated plasma. Also, the RF antenna 1
A power supply 18 is connected to 2 and 12 via a matching network 17, and a power supply 20 is connected to the RF antenna 13 via a matching network 19.

The diffusion chamber 11 is provided with the wafer stage 1 for holding and fixing a sample wafer W, and an exhaust port 21 for exhausting the gas in the diffusion chamber 11 is a vacuum pump or the like. It is formed by being connected to negative pressure means (not shown). Wafer stage 1
Is connected to a bias power source 22 for controlling the energy of ions incident on the wafer W, and the temperature control jacket 2 has D for causing the dielectric film 4 to exert an electrostatic adsorption force.
The C power supply 23 is connected.

A temperature medium supply device 25 is connected to the temperature medium pipe 6 of the temperature control jacket 2 of the wafer stage 1 via pipes 24a and 24b, and fluorescent light for measuring the temperature of the wafer W is further provided. A fiber thermometer 26 is connected. The heating medium supply device 25 supplies a heating medium (heating medium) such as silicon oil into the heating medium pipe 6 of the wafer stage 1 via the pipe 24a and is returned from the heating medium pipe 6 via the pipe 24b. The heating medium is received and further heated to a predetermined temperature. By circulating the heating medium (heating medium) in the heating medium pipe 6 in this way, the wafer W held and fixed on the wafer stage 1 is heated. It is a thing.

A pipe 24a connected to the heating medium supply device 25
Is equipped with a control valve 27 capable of operating at high temperature,
In addition, the bypass pipe 28 between the pipe 24a and the pipe 24b
Also, a control valve 27 is provided. Then, under such a configuration, by controlling the control valves 27, 27, the supply amount of the heat medium to the heat medium pipe can be adjusted. The supply amount of the heat medium is detected by the control device (PID controller) 29, which is the temperature detected by the fluorescent fiber thermometer 26. Based on the difference from the temperature of the wafer W set in advance, an experiment or It is determined by the controller 29 so that the heat medium supply amount determined by calculation is obtained.

However, in the wafer stage 1 shown in FIG. 1, although it depends on the set temperature of the wafer W, the heating by the heater 5 is usually the main, and the heating by the supply of the heat medium (heat medium) is the temperature of the wafer W. Auxiliary heating for stability. That is, when plasma etching is performed,
Since the heat input from the plasma is received by the wafer W and further by the wafer stage 1, it is difficult to maintain the wafer W at the set temperature only by heating with the heater 5, but it is performed in addition to the heating of the heater 5. As heating by supplying heat medium,
Actually, in order to keep the wafer W at the set temperature, the heat input from the plasma is offset so as to supply a heat medium having a temperature lower than the set temperature, whereby the wafer W is stabilized at the set temperature. In FIG. 2, details of the apparatus such as the etching gas introduction hole and the gate valve are omitted.

Next, an example of a dry etching treatment method using such an etching apparatus 10 is shown in FIG.
This will be described with reference to (b). This processing method is shown in FIG.
As shown in (a), a wiring pattern made of Cu is formed on the SiO ₂ layer 41 formed on the silicon wafer 40 by plasma etching.
That is, in this example, first, a TiN film 42 is formed as an adhesion layer on the SiO ₂ layer 41 on the silicon wafer 40 by a sputtering method, and then a Cu film 43 is formed thereon by a sputtering method or the like. Further, a TiN film 44 was formed thereon. Then, Si is formed on the TiN film 44.
An O ₂ film (not shown) was formed, and the SiO ₂ film was patterned by a known lithography technique and etching technique to form a mask pattern 45 made of the SiO ₂ film as shown in FIG. 4A.

Next, the silicon wafer 40 on which the mask pattern is formed is placed on the wafer stage 1 in the etching apparatus 10, and the temperature adjustment jacket 2 is made to exert electrostatic adsorption force to hold and fix the silicon wafer 40. The silicon wafer 40 was adjusted to the following set temperature by performing heating by supplying the heater 5 and the heat medium (heat medium). And
Using this mask pattern 45 as a mask, T
The iN film 44, the Cu film 43, and the TiN film 42 were etched to obtain a wiring pattern 46 as shown in FIG. Etching gas; Cl _{2 3} sccm pressure; 5 mTorr Source power 1 (RF antenna 4); 1500 W (13.56 Hz) Source power 2 (RF antennas 3 and 3); 1500 W (13.56 Hz) RF bias; 350 W Wafer temperature; 250 ° C.

When the etching was performed in this manner, almost no temperature rise of the silicon wafer 40 due to heat input from the plasma was observed even during the etching, and the temperature of the silicon wafer 40 set at the set temperature (25
It could be kept stable at 0 ° C. Since the temperature can be stabilized with high accuracy in this way, a good anisotropic wiring pattern can be obtained despite using Cl ₂ alone as an etching gas. As a result, the Cu film could be processed well.

For comparison, when the temperature change of the silicon wafer 40 was examined under the same conditions as described above by only performing heating with the temperature control jacket 2 without exhibiting the electrostatic chuck function, the silicon wafer 40 The temperature was 190 ° C., which was considerably lower than the set temperature, because sufficient heating was not performed at the start of the treatment. The temperature also increased with the progress of the treatment, and reached the set temperature of 250 ° C. about 60 seconds after the treatment was started. However, when the treatment was further continued, the temperature increased further due to the heat input from the plasma, and the temperature rose to about 265 ° C. 120 seconds after the treatment was started. Therefore, it was confirmed that in the wafer stage 1 of the present invention, by exerting the electrostatic attraction force, temperature control can be performed with high accuracy, which was impossible in the past.

Next, another example of the dry etching method using the etching apparatus 10 shown in FIG. 3 will be described with reference to FIG.
This will be described with reference to (a) and (b). This processing method is
As shown in FIG. 5A, a contact hole is formed in a SiO ₂ layer 51 formed on a silicon wafer 50 by using a sidewall 52 made of polysilicon as a mask. That is, in this example, first, a SiO ₂ layer 51 having a thickness of 1.0 μm is formed on a silicon wafer 50, and then a polysilicon layer 53 is formed thereon, and a contact hole is formed in the polysilicon layer 53. 54 was formed. Next, a polysilicon layer (not shown) was formed again so as to be deposited also on the inner wall surface of this contact hole 54, and this was etched back to form a sidewall 52 in the contact hole 54. The diameter of the holes surrounded by the sidewalls 52 thus formed was 0.1 μm.

Then, the silicon wafer 50 having the sidewalls 52 formed thereon is placed on the wafer stage 1 in the etching apparatus 10, and the temperature control jacket 2 is made to exert an electrostatic adsorption force in the same manner as in the previous example. The wafer 50 was held and fixed, and heating was performed by supplying the heater 5 and a heat medium (heat medium) to adjust the silicon wafer 50 to the following set temperature. Then, using the sidewall 52 as a mask, the SiO ₂ layer 51 is etched under the following conditions.
As shown in (b), a contact hole 55 communicating with the contact hole 54 was formed. Etching gas; C ₄ F ₈ / CO / Ar 8/120/150 sccm pressure; 5 mTorr Source power 1 (RF antenna 4); 1500 W (13.56 Hz) Source power 2 (RF antennas 3 and 3); 1500 W (13.56 Hz) ) RF bias: 350W Wafer temperature: 150 ° C

Conventionally, such a contact hole 5 is formed.
In the case of forming No. 5, since the diameter of the hole surrounded by the sidewall 52 is as small as 0.1 μm, the hole is filled with the fluorocarbon polymer which is a reaction product at a normal temperature, and the SiO ₂ layer 51 is not etched. Therefore, the contact hole 55 could not be formed well. In addition, when the high temperature heating is performed without performing sufficient temperature control, the fluorocarbon polymer is not deposited at all and the shape becomes bowing, so that it is impossible to secure the selection ratio to the underlayer.

However, according to the above method using the wafer stage 1, the silicon wafer 50 can be stabilized with high accuracy at the set temperature, and high-precision etching can be performed. By setting the temperature of the silicon wafer 50 in a temperature range in which polymer deposition can be controlled and performing etching, it is possible to form a contact hole 55 having an ultrafine and high aspect ratio as shown in FIG. 5B. It was

[0041]

As described above, the wafer stage of the present invention is provided with a thermal buffer layer having a linear expansion coefficient between a metal having a large linear expansion coefficient and an insulating material having a small linear expansion coefficient. By forming the dielectric film on the layer, when the dielectric film is heated by the temperature control jacket when the wafer is heated, the dielectric film is heated directly through the thermal buffer layer without direct heat conduction. Since it is made to be conducted, it is possible to prevent the dielectric film from cracking or peeling due to the difference in the linear expansion coefficient between the dielectric film and the temperature control jacket. As a result, the wafer can be heated to a high temperature without any trouble, and the temperature can be controlled with high accuracy even in a high temperature range without causing a large temperature rise due to heat input from plasma, for example. Therefore, by using this wafer stage, it is possible to perform favorable anisotropic processing on a material such as Cu, and also to form contact holes having an ultrafine and high aspect ratio. it can. Also,
Since the dielectric film is formed on the temperature control jacket by the thermal spraying method, the temperature control jacket and the dielectric film are more integrated, and the stress between them can be relieved and the temperature control can be achieved. The heat conduction from the adjusting jacket to the dielectric film can be accelerated, so that the damage of the dielectric film can be further suppressed and the temperature control of the wafer can be performed more quickly.

In the method of manufacturing a wafer stage of the present invention, molten aluminum or a molten aluminum alloy is poured into porous Al ₂ O ₃ provided at the bottom of the mold, and a temperature control jacket is formed by a high pressure casting method to form a porous jacket. Since the Al ₂ O ₃ portion is a composite material having an intermediate property between Al ₂ O ₃ and aluminum or an aluminum alloy, an insulating material is formed by a thermal spraying method on the surface of the porous alumina side to form a dielectric material. By forming the body membrane,
A dielectric film made of an insulating material can be indirectly connected to aluminum or an aluminum alloy, which is the main body of the temperature control jacket, through the porous alumina portion having a linear expansion coefficient close to that of the dielectric film. Therefore, in the obtained wafer stage, it is possible to prevent the dielectric film from cracking or peeling due to the difference in the linear expansion coefficient between the dielectric film and the temperature control jacket. .

According to this dry etching apparatus, since it is equipped with the wafer stage, there is no inconvenience such as cracking of the dielectric film on the wafer stage even when the high temperature etching process is performed, and the wafer stage is also provided. The wafer electrostatically attracted onto the wafer is heated to a desired temperature, for example, 20
It can be stabilized at a high temperature such as 0 to 250 ° C., and thus, as described above, good anisotropic processing can be performed on a material such as Cu, and contact holes of ultrafine and high aspect ratio can be formed. It can also be possible to form.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a schematic configuration of a wafer stage of the present invention.

FIG. 2 is a side sectional view for explaining a method of manufacturing the wafer stage shown in FIG.

FIG. 3 is a schematic configuration diagram of a dry etching apparatus of the present invention.

4A and 4B are side cross-sectional views of main parts for explaining an example of a dry etching processing method by the etching apparatus shown in FIG. 3 in the processing order.

5A and 5B are side cross-sectional views of a main part for explaining another example of the dry etching processing method by the etching apparatus shown in FIG. 3 in the processing order.

[Explanation of symbols]

1 Wafer stage 2 Temperature control jacket 3 Thermal spraying base layer 4 Dielectric film 5 Heater 6 Heat medium pipe 7
Thermal buffer layer 10 Dryer etching device 25 Hot medium supply device 30 Mold 31 Porous alumina 33 Molten aluminum
W wafer

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Megumi Takatsu 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Within Sony Corporation (56) Reference JP-A-8-316299 (JP, A) JP-A 6-216224 (JP, A) JP-A-7-126827 (JP, A) JP-A-5-67673 (JP, A) JP-A-2-220754 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/68 H01L 21/3065 H02N 13/00

Claims (5)

(57) [Claims] 1. A wafer stage in which a temperature control jacket is provided with an electrostatic chuck function, wherein the temperature control jacket has a heater and a heat medium pipe connected to a temperature control means embedded therein. On its upper surface,
It is made of aluminum or an aluminum alloy integrated with a heat buffer layer, and the heat buffer layer is formed by pouring aluminum or an aluminum alloy into the holes of a plate-like porous Al ₂ O _{3 to} form a composite. And a dielectric film made of an insulating material is formed on the thermal buffer layer of the temperature control jacket by a thermal spraying method, and the temperature control jacket is used as an electrode. A wafer stage, wherein the temperature control jacket and the dielectric film function as an electrostatic chuck. 2. A thermal spray base layer made of a material having a coefficient of linear expansion between the coefficient of linear expansion of the thermal buffer layer and the coefficient of linear expansion of the dielectric film is provided between the thermal buffer layer and the dielectric film. The wafer stage according to claim 1, wherein the wafer stage is formed by a thermal spraying method. 3. A plate-like porous Al ₂ O ₃ is provided at the bottom of the mold.
And a heater and a heating medium pipe are provided thereon, and molten aluminum or molten aluminum alloy is poured into the mold in this state to form a temperature control jacket by a high pressure casting method, and then the temperature control jacket Porous Al ₂ O
_A method of manufacturing a wafer stage, comprising forming a dielectric film by forming an insulating material on the surface on the side ₃ by a thermal spraying method. 4. A line of a thermal buffer layer formed by pouring molten aluminum or molten aluminum alloy into the porous Al ₂ O ₃ after forming the temperature control jacket and before forming a dielectric material film. The material having a coefficient of linear expansion between the coefficient of expansion and the coefficient of linear expansion of the insulating material is formed on the thermal buffer layer by a thermal spraying method to form a thermal spraying base layer. A method for manufacturing a wafer stage as described. 5. A wafer stage in which a temperature control jacket is provided with an electrostatic chuck function, wherein the temperature control jacket has a heater and a heat medium pipe connected to a temperature control means embedded therein. The upper surface is made of aluminum or an aluminum alloy integrated with a thermal buffer layer, and the thermal buffer layer is a plate-shaped porous Al ₂ O ₃
Is formed by pouring aluminum or an aluminum alloy into the holes of the composite, and a dielectric film made of an insulating material is formed on the thermal buffer layer of the temperature control jacket by a thermal spraying method. The temperature control jacket is used as an electrode so that the temperature control jacket and the dielectric film can function as an electrostatic chuck. Dry etching equipment.