JPH0945751A - Dummy wafer for plasma equipment - Google Patents

Abstract

(57) A dummy wafer for a plasma device having plasma resistance and capable of being charged with an electrostatic charge is obtained, and the dummy wafer can be used in a plasma device equipped with an electrostatic chuck. A charged body 3 that can be charged with an electrostatic charge is formed of a conductor, a semiconductor, or a dielectric. The coating material 5 having the concave portion 7 capable of accommodating the charged body 3 is formed of a material having plasma resistance. The charged body 3 is housed and bonded in the concave portion 7 by using the pair of coating materials 5 and 5 having the same shape, and the dummy wafer 1 for the plasma device is configured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dummy wafer used for various plasma devices in a semiconductor manufacturing process.

[0002]

2. Description of the Related Art In recent years, various plasma devices have been frequently used in the semiconductor manufacturing process in order to reduce thermal history.
In this case, in order to improve the semiconductor production efficiency, it is desired to increase the operating rate of the plasma device. In order to increase the operating rate of the plasma device, it is important to reduce the downtime of the device, for example, reducing the frequency of wet cleaning.

One of the methods for reducing the frequency of wet cleaning is so-called plasma cleaning, in which a suitable plasma is raised to sublimate and exhaust the reaction products to remove foreign substances adhering to the reaction chamber. With plasma cleaning, the frequency of wet cleaning can be reduced to some extent. When performing such plasma cleaning, it is indispensable to dispose a dummy wafer in the apparatus in order to prevent the lower electrode from being directly exposed to plasma.

Further, in order to stably manufacture a semiconductor, it is desirable that the plasma state of the device is stable. However, in the plasma apparatus, heat is accumulated by the plasma treatment, and the temperature inside the apparatus rises and changes at the initial stage of operation, so that the temperature becomes unstable. Therefore, in the initial stage of operation, so-called dummy processing is performed in which plasma processing equivalent to an actual process is performed on several dummy wafers in order to eliminate temperature changes and stabilize the apparatus temperature.
Even in this case, in order to prevent the lower electrode from being damaged by the plasma processing, it has been essential to dispose the dummy wafer in the apparatus.

[0005]

As described above, in the plasma apparatus, the frequency of use of the dummy wafer has been high due to the plasma cleaning or the dummy processing. Therefore, in consideration of cost, in each plasma device, it is possible to use a single plate made of a material having high resistance to each plasma processing as a dummy wafer and increase the number of times the dummy wafer can be used. Was there. However, in recent years, the manufacturing of semiconductors has tended to shift to a full-face process method, and accordingly, an electrostatic chuck method has been introduced as a wafer holding method of a plasma device. In the electrostatic chuck method, a voltage is applied between the electrode and the wafer, and the wafer is attracted by the Coulomb force generated between them. At this time, the detection as to whether or not the chuck is performed is detected by the current flowing during the chuck. Therefore, if the dummy wafer has a single plate structure that is a conventional insulator,
The chuck current does not flow, an error occurs during chucking, and the original function of the dummy wafer cannot be fulfilled. The present invention has been made in view of the above circumstances, and provides a dummy wafer for a plasma device that can be used even in a plasma device having an electrostatic chuck to reduce the downtime of the plasma device and improve the reliability of the overall process method. The purpose is to

[0006]

The structure of a dummy wafer for a plasma device according to the present invention for achieving the above object is as follows.
A dummy wafer for a plasma device, which is used when performing plasma cleaning or dummy processing in various plasma devices, comprising a charged body made of any one of a conductor, a semiconductor, or a dielectric, and a material having plasma resistance. A recess for accommodating a body is formed, and a set of coating materials having the same shape for accommodating and bonding the charged body in the recess are provided. In the dummy wafer for a plasma apparatus configured as described above, electrostatic charges can be charged inside the charged body covered with the coating material, that is, the inside of the wafer, and it can be used in an electrostatic chuck type plasma apparatus.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a dummy wafer for a plasma device according to the present invention will be described in detail below with reference to the drawings. FIG. 1 is an exploded perspective view showing a first embodiment of a dummy wafer according to the present invention. In the dummy wafer 1 according to this embodiment, the disk-shaped charged body 3 is sandwiched by the pair of coating materials 5 and 5 from the front and back surfaces. The charging body 3 is made of a conductor, a semiconductor, or a dielectric. The coating materials 5 and 5 are formed in the same shape, and a concave portion 7 for accommodating substantially half the thickness direction of the charging body 3 is formed on the surface sandwiching the charging body 3. The covering materials 5 and 5 that accommodate the charged body 3 in the recess 7 and are superposed on each other are joined together by bonding the joint surfaces 9 around the recess. The joining surface 9 is joined by a method using a resin adhesive or welding by heating.

Since the dummy wafer 1 can be constructed by joining a pair of covering materials 5 and 5 which are the same shaped parts, it is possible to assemble with a small number of kinds of parts.

FIG. 2 is an exploded perspective view showing a modified example of the dummy wafer bonding structure. As for the bonding structure of the dummy wafer 1, in addition to the structure of bonding the covering materials 5 and 5 having the same shape as described above, as shown in FIG.
May be formed on the lower surface of the upper covering material 13, the charged body 3 is housed therein, and then the lid body 15 which is a disk-shaped covering material is closed. The dummy wafer 17 configured as described above
Is the lid 15 on the lower electrode side of the plasma device (not shown).
The sides are arranged so as to face each other.

In the dummy wafer 17 according to this modification,
Since the lid body 15 can be inserted into the concave portion 11 to be closed, the positioning at the time of joining can be easily performed, and the upper covering material 1
Since the joint between the lid 3 and the lid 3 is on the lower surface side of the dummy wafer 17, it is possible to reduce adverse effects such as micro-arcing.

In the above-mentioned dummy wafers 1 and 17, since the charging body 3 can be coated by joining the single-body coating materials 5, 13 and 15 that have been molded, ceramics, hard glass, sapphire, carbon graphite,
It is suitable for manufacturing a dummy wafer with a coating material using an inorganic material such as silicon carbide.

According to the above-mentioned dummy wafers 1 and 17,
The charged body 3 is the covering materials 5 and 5, or the upper covering material 13 and the lid body 1.
Since it is covered with 5, electrostatic charges can be charged inside the wafer, and even in the electrostatic chuck type plasma device, the dummy wafers 1 and 17 can be reliably chucked, and the chucking error is prevented so that the device is down. Time can be reduced. As a result, the production efficiency and reliability of the whole process can be improved.

Next, a second embodiment of the dummy wafer according to the present invention will be described. FIG. 3 is a partially cutaway perspective view showing a second embodiment of the dummy wafer according to the present invention. In the dummy wafer 21 according to this embodiment,
The disk-shaped charged body 3 is coated with a coating material 23 having high plasma resistance. The dummy wafer 21 having such a structure is suitable for manufacturing a dummy wafer in which a resin material such as Lexan resin or Vespel resin is used for the covering material 23.

According to the dummy wafer 21, as in the above-described embodiment, even in the electrostatic chuck type plasma device, reliable chucking can be performed, the downtime of the device can be reduced, and the charged body 3 can be reduced. Since it is completely covered with the coating, the shielding property of the charged body 3 can be made particularly excellent.

Next, a third embodiment of the dummy wafer according to the present invention will be described. FIG. 4 is a perspective view showing a third embodiment of the dummy wafer according to the present invention. In this dummy wafer 31, a charging body thin film 35 of a conductor, a semiconductor, a dielectric or the like is formed on the back surface of a single plate 33 formed of a coating material having high plasma resistance. The charged body thin film 35 is formed by a method such as sputtering film formation, CVD film formation, vapor deposition film formation, or a method in which a previously formed charged body thin film 35 is attached to the back surface of the single plate 33 by a resin adhesive or the like. Done in. In this case, in any of the dummy wafers 31 manufactured by any method, the charging body thin film 35 is formed in a region slightly inside the edge of the single plate 33 in order to prevent the adverse effect of micro-arcing during the plasma processing. It is desirable to be done.

According to the dummy wafer 31, as in the above-described embodiment, even in the electrostatic chuck type plasma apparatus, reliable chucking can be performed, the apparatus downtime can be reduced, and the charged body thin film 35 can be reduced. Since it can be configured by laminating, it is possible to use a conventional single plate, and since the structure is simple, it can be manufactured relatively easily.

Next, a description will be given of a coating material suitable for various plasma devices in the dummy wafers 1, 17, 21, 31 constructed as described above. For the dummy processing of the tungsten edge back device, dummy wafers 1, 17, 2 are used.
When 1 and 31 are used, the reaction gas used when shaving the tungsten film is usually a fluorine-based gas, and when shaving the adhesion layer, a chlorine-based gas is used. , 17, 21, 31 include ceramics, sapphire, carbon graphite,
Silicon carbide and resin materials are suitable.

When the dummy wafers 1, 17, 21, and 31 are used for cleaning the tungsten edge-back device, the side reaction product produced in the tungsten edge-back process is mainly used for the adhesion layer. Since it is a titanium-based reactant and plasma cleaning with chlorine-based gas is effective, the dummy wafers 1, 17,
Ceramics, hard glass, sapphire, carbon graphite, silicon carbide, resin materials and the like are suitable as the coating material for 21 and 31.

When the dummy wafers 1, 17, 21, and 31 are used for the dummy processing of the aluminum-based wiring material etching apparatus, the reaction gas used when shaving the aluminum-based wiring material is usually a chlorine-based gas. Since hydrogen bromide is rarely used, ceramics, hard glass, sapphire, carbon graphite, silicon carbide, resin materials and the like are suitable as the coating material for the dummy wafers 1, 17, 21, 31.

Further, the dummy wafers 1, 17, 21, 3 are used for the dummy processing of the polysilicon type wiring material etching apparatus.
When 1 is used, the reaction gas used when shaving the polysilicon wiring material is usually a chlorine gas, and hydrogen bromide is rarely used. Therefore, the dummy wafers 1, 17,
Ceramics, hard glass, sapphire, carbon graphite, silicon carbide, resin materials and the like are suitable as the coating material for 21 and 31.

When the dummy wafers 1, 17, 21, and 31 are used for the dummy processing of the oxide film etching apparatus, the reaction gas used for removing the oxide film is usually fluorine gas, so that the dummy wafer 1 is used. , 17, 21, 3
As the coating material of No. 1, ceramic, sapphire, carbon graphite, silicon carbide, resin material and the like are suitable.

In this way, by selecting a coating material having resistance corresponding to each plasma device,
The dummy wafers 1, 17, 21, and 31 can be used more times per sheet. As a result, the consumption of the dummy wafers 1, 17, 21, 31 can be reduced, and the material cost of consumables can be reduced.

[0023]

As described in detail above, according to the dummy wafer for a plasma apparatus of the present invention, since the charging body is covered with the coating material, electrostatic charges can be charged inside the wafer, and the electrostatic chuck can be charged. Also in the plasma type plasma apparatus, the dummy wafer can be securely chucked.
As a result, device downtime can be reduced by preventing chuck errors, and production efficiency and reliability of the entire process can be improved.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a first embodiment of a dummy wafer according to the present invention.

FIG. 2 is an exploded perspective view showing a modified example of the dummy wafer bonding structure.

FIG. 3 is a partially cutaway perspective view showing a second embodiment of a dummy wafer according to the present invention.

FIG. 4 is a perspective view showing a third embodiment of a dummy wafer according to the present invention.

[Explanation of symbols]

 1, 17, 21, 31 Dummy wafer for plasma device 3 Charged body 5, 13, 15, 23 Coating material 7, 11 Recessed portion 33 Single plate 35 Charged body thin film

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H01L 21/3065 H01L 21/302 B

Claims (6)

[Claims] 1. A dummy wafer for a plasma device, which is used when performing plasma cleaning or dummy processing in various plasma devices, and which has a charged body made of any one of a conductor, a semiconductor, and a dielectric, and plasma resistance. A dummy wafer for a plasma device, comprising: a recess made of a material for accommodating the charged body; and a set of coating materials having the same shape for accommodating and bonding the charged body in the recess. 2. A dummy wafer for a plasma device, which is used when performing plasma cleaning or dummy processing in various plasma devices, and which has a charged body made of any one of a conductor, a semiconductor, and a dielectric, and plasma resistance. A dummy wafer for a plasma device, comprising a coating material made of a material and coated to cover the charged body. 3. The dummy wafer for plasma device according to claim 2, wherein the coating material is either Lexan resin or Vespel resin. 4. A dummy wafer for a plasma device, which is used when performing plasma cleaning or dummy processing in various plasma devices, which is a single plate made of a material having plasma resistance, a conductor, a semiconductor, or a dielectric. A dummy wafer for a plasma device, comprising: a thin film of a charging body, which is formed of the single plate and is attached to one surface of the single plate. 5. The ceramic material, hard glass, sapphire, carbon graphite, or silicon carbide is used as the coating material or the single plate as the material having etching resistance. Dummy wafer for plasma equipment. 6. The dummy wafer for a plasma device according to claim 4, wherein the charged body thin film is deposited by vapor deposition or an adhesive.