JPH07273096A - Method of forming junction and jointing method between members of treatment apparatus - Google Patents

Abstract

PURPOSE:To provide the method of forming a junction and a jointing method between the members of a treatment chamber which facilitate the suppression of the production of particles from the junction between the members which requires an electric continuity. CONSTITUTION:A process in which a protrusion 50 is formed on the surface junction part 48 of a conductive member, a process in which an insulating layer 53 is formed at least on the surface of the conductive member having the protrusion 50, a process in which the part of the insulating layer 53 on the surface of the protrusion 50 is removed and a process in which a member to be jointed is jointed with the protrusion surface from which the insulating layer is removed are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a joint and a method for joining members of a processing apparatus.

[0002]

2. Description of the Related Art Generally, in a semiconductor manufacturing process, for example, an etching processing apparatus is used as a processing apparatus for processing an object to be processed, for example, a semiconductor wafer. In this etching apparatus, for example, as shown in FIG. 5, a mounting table 101 as a lower electrode is provided in a processing chamber 100 as an airtight chamber configured to be decompressible, and an opening provided in a sidewall of the processing chamber 100. The semiconductor wafer W is mounted from 102 via an opening / closing means such as a gate valve 103. A high frequency power supply 105 is connected to the mounting table 101 via a blocking capacitor 104. In addition, a gas introduction pipe 10 for introducing a processing gas into the processing chamber 100 is provided at a position facing the mounting table 101.
6, an upper electrode 107 communicating with 6 is provided, and a processing gas is further introduced in the direction of the semiconductor wafer W through a small hole 108 provided in the upper electrode 107. The upper electrode 107 is electrically grounded, and the mounting table 10
When the high frequency power source 105 is turned on, the high frequency power is applied to the processing gas 1 to turn the processing gas into plasma, and the semiconductor wafer W is processed by the active species in the plasma.

The upper electrode 107 is composed of a plurality of members, for example, a conductive member, for example, a ceiling wall A having aluminum as a base, a side wall B, and a bottom wall C. These members A, B, C are used. An insulating layer such as an aluminum alumite treatment is applied to the surface of the. And each member A,
The members B and C are electrically connected to each other so as to have the same electric potential in order to prevent abnormal discharge.
As a method of connecting these members, as shown in FIG. 6, the bottom wall C is provided with a recess 110 for joining the side wall B member. The surface of the bottom wall C is as described above. Since the aluminum is anodized as an insulating layer, the aluminum which is the base material is directly exposed after being machined to form the recess 110. Naturally, the contact surface 111 of the recess 110 of the side wall B is also an aluminum alumite on the surface. The layer was shaved and the base material, aluminum, was exposed to establish electrical conduction with the bottom wall C, and the potential was set to a preset value. Then, the side wall B and the bottom wall C were fixed to each other with, for example, a bolt 112.

[0004]

However, since plasma is generated in the above-described etching apparatus, as shown in FIG. 6, in the concave portion 110 of the bottom wall C, the exposed portion 113 of aluminum other than the contact portion with the side wall B is exposed. There has been a problem that etching is performed by active species in plasma, for example, ions, and the etching product is scattered as particles in the processing chamber. Further, if the particles adhere to the object to be processed, there is a problem that the yield of the object to be processed decreases. Furthermore, not only etching equipment but also many semiconductor processing equipment generally use various corrosive gases, for example, chlorine-based gas,
There is a problem that such a gas corrodes the above-mentioned place 113, and the corroded material is scattered as particles in the processing chamber. Furthermore, such corrosion is at point 11
3 as well as the contact portion 111 between the bottom wall C and the side wall B, electrical conduction becomes unstable, and further corrosion progresses, electrical conduction cannot be achieved, thereby causing a potential difference between members. There is a problem that abnormal discharge occurs in a device that generates plasma and generates plasma. If such an abnormal discharge occurs, not only the generation of particles, but there is a risk that impedance matching with the high frequency power supply may not be obtained, and if the impedance is not matched, the supply of high frequency power becomes unstable,
When the object to be processed is processed in such a state, there is a problem that the yield of the object to be processed decreases. The present invention has been made to pay attention to the above problems and to solve them effectively. An object of the present invention is to provide a method for forming a joint and a method for joining members of a processing apparatus capable of suppressing generation of particles from a joint between members that need to be electrically conducted. .

[0005]

According to the present invention, in order to solve the above-mentioned problems, in the invention of claim 1, a step of forming a convex portion on a surface joint portion of a conductive member, and at least the conductive member. The method further comprises a step of forming an insulating layer on a surface having a convex portion, a step of removing the insulating layer on the convex surface, and a step of bonding a member to be joined to the removed convex surface. And In the invention of claim 2, the step of forming a convex portion on the surface of the conductive member, the step of forming an insulating layer having a thickness covering the convex portion on the surface of the member, and the surface of the convex portion are And a step of polishing the insulating layer and the convex portion until at least protruding, and mirror-finishing the surface of the member on the joint side. Further, claim 3
In the invention of claim 1, there is provided a method of joining members for electrically connecting between members forming a processing apparatus for heat-treating or plasma-treating an object to be treated in a reduced pressure atmosphere, wherein at least one of the members has a convex portion. The step of forming, the step of forming an insulating layer on the joint side surface of those members, the step of removing the insulating layer on the surface of the convex portion, and the member to be joined to the convex surface exposed in this step. And a step of bringing them into contact with each other. According to a fourth aspect of the present invention, there is provided a method of joining members for electrically connecting between members forming a processing apparatus that heat-treats or plasma-treats an object to be processed, the joining portion of each member. The step of forming a convex portion on the side surface, the step of forming an insulating layer having a thickness covering the convex portion on the surface of the joint portion side of those members, and polishing the insulating layer to the surface of the convex portion. Further, the method further comprises the steps of polishing the insulating layer and the convex portion at the same time, mirror-finishing the surface of the member on the joint portion side, and bringing the convex portions of the respective members into contact with each other. .

[0006]

Since the present invention is configured as described above, a convex portion is formed on the connection surface of a conductive member that needs to be electrically conducted, and an insulating layer having a thickness that covers the convex portion on the surface of the member. And polishing the insulating layer and the convex portion at least until the surface of the convex portion is projected, and the members are joined by mirror-finishing the surface on the joint portion side of the member, so that the joint portion between these members is Since it is possible to suppress the etching by the plasma and the corrosion due to the corrosive gas, it is possible to suppress the generation of particles between the members.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for forming a joint and a method for joining members of a processing apparatus according to the present invention will be described in detail below with reference to the accompanying drawings. In this embodiment, a low temperature plasma etching apparatus will be described as an example of the processing apparatus.

As shown in FIG. 1, this etching apparatus 1
Has a processing container 2 which is formed into a cylindrical or rectangular shape from a conductive material, for example, aluminum whose surface is anodized, and the like. A mounting table 4 as a substantially cylindrical lower electrode for mounting an object to be processed, for example, a semiconductor wafer W, is attached. The mounting table 4 is constructed by assembling a plurality of members, which will be described later, whose surfaces are formed of aluminum or the like, which is anodized, with fixing means such as bolts. Specifically, the mounting table 4 is mainly composed of a susceptor support table 5 formed of aluminum or the like in a cylindrical shape, and a susceptor 7 made of aluminum or the like that is detachably provided by bolts 6 on the susceptor support table 5. ing.

Inside the susceptor support 5, cooling means,
For example, a cooling jacket 8 is provided, and a coolant such as liquid nitrogen is introduced into the jacket 8 through a coolant introduction pipe 10 to circulate in the jacket 8 and a liquid is discharged from a coolant discharge pipe 11 by evaporation of the liquid nitrogen. The gas is discharged to the outside of the container 2, cooled, and then circulated through the refrigerant introduction pipe 10 again. Therefore, the cold heat of the liquid nitrogen at −196 ° C. is supplied from the cooling jacket 8 to the wafer W via the susceptor 7, and the wafer W can be cooled to a desired temperature.

The susceptor 7 is formed in a disk shape having a projecting upper end center portion, and the electrostatic chuck 13 is not exposed to plasma in the wafer mounting portion at the center thereof, which is substantially the same as the wafer area. As described above, it is formed in an area slightly smaller than the area of the wafer W. The electrostatic chuck 13 is formed, for example, by sandwiching a conductive film 14 such as a copper foil in an insulating state between two sheets of polymer polyimide film, and the conductive film 14 is cut by a voltage supply lead 15 from high frequencies. It is connected to a variable DC high voltage source 17 via a filter 16 such as a coil. Therefore, this conductive film 1
By applying a high voltage to the wafer 4, the wafer W can be sucked and held on the upper surface of the chuck 13 by Coulomb force.

The susceptor support 5 and the susceptor 7
The heat transfer gas such as He penetrates the wafer W
A gas passage 20 is formed to supply the gas to the back surface, the joints between these, the joints between the members forming the susceptor 7, and the like. The electrostatic chuck 13 is also formed with a large number of vent holes (not shown) through which the heat transfer gas passes. An annular focus ring 21 is arranged on the upper edge of the susceptor 7 so as to surround the wafer W. The focus ring 21 is made of an insulating material that does not attract reactive ions, and is configured so that the reactive ions are effectively incident only on the semiconductor wafer W inside.

A pipe lead 22 made of a hollow conductor is connected to the susceptor 7 through the susceptor support 5 and a blocking capacitor 24 is connected to the pipe lead 22 via a wire 23. Further, a high frequency power source 25 for plasma generation of, for example, 13.56 MHz or 40.68 MHz is sequentially connected. Therefore, the susceptor 7 is configured as a lower electrode. Further, the exhaust pipe 2 is provided on the lower side wall of the processing container 2.
7 is connected so that the atmosphere in the processing container 2 can be discharged by an exhaust pump (not shown), and a gate valve (not shown) is provided on the side wall of the central portion, through which wafers can be loaded and unloaded. Is configured to do.

A temperature adjusting heater 2 is provided below the susceptor between the electrostatic chuck 13 and the cooling jacket 8.
8 are provided. This heater 28 has a thickness of, for example, a few mm.
The heater 28 is made of a plate-shaped ceramics heater, and is completely accommodated on the upper surface of the heater fixing base 29 fixed to the upper surface of the susceptor supporting base 5 by a bolt or the like (not shown) with its upper surface at the same level. Heater fixing stand 29
Is made of a material having good thermal conductivity, such as aluminum. The size of the heater 28 is preferably set to be approximately the same as or larger than the wafer area, and the cooling heat from the cooling jacket 8 located below this is conducted to the wafer W. The temperature of the wafer W can be controlled and adjusted. A through hole (not shown) through which a pusher pin or the like penetrates is formed in the temperature adjusting heater 28 and the heater fixing base 29.

An accommodating recess 30 for accommodating the entire heater fixing base 29 is formed on the lower surface of the susceptor 7, and the upper surface of the heater 28 and the accommodating recess 30 of the susceptor 7 are formed in the heater fixing base 29. At the boundary with the bottom surface of
A branch passage 31 connected to the gas passage 20 is formed for supplying a heat transfer medium such as. A power supply lead 32 is connected to the heater 28, and a power source 33 is connected to the lead 32 so that a predetermined power can be supplied to the heater 28.

Further, all kinds of wirings that are susceptible to high frequency for plasma generation, such as the power supply lead 32 connected to the heater and the voltage supply lead 15 connected to the electrostatic chuck 13, all supply high frequency power for plasma. It is housed in the supply pipe lead 22 so that high frequency noise does not affect the outside. An insulator 35 is provided in a penetrating portion of the bottom of the processing container of the pipe lead 22 to electrically insulate it from the container 2 side. Further, a shield 36 that is electrically grounded is provided on the outer circumference of the pipe lead 22 that extends to the outside of the container 2 so that high frequency waves do not leak to the outside.

Further, a grounded upper electrode 40 is disposed above the susceptor 7 at a distance of about 3 to 20 mm from the susceptor 7. The upper electrode 40 is processed through a gas supply pipe 41 through a process. A gas, for example, an etching gas such as CF4 is supplied to the gas supply pipe 41 and the upper electrode 4.
The etching gas is evenly diffused through the small holes 43 of the gas diffusion plate 42 provided between the upper and lower sides of the gas diffusion plate 42, and the etching gas is blown into the lower processing space through the large number of small holes 44 formed in the upper electrode 40. Is configured.

At the joint portion between the upper electrode 40 and the members forming the processing container 2, the convex portion 45 as a member to be joined provided in the processing container 2 and the upper electrode 40 are joined. 2 and are connected by connecting means, for example, bolts 46, as shown in FIG. These joints are formed by a conductive member of the convex portion 45 and the upper electrode 40, for example, aluminum 4
An insulating film, such as alumina or aluminum alumite 47, is applied to the surface of 9 to prevent sputtering by plasma and corrosion by corrosive gas. This insulating film joins the convex portion 45 with the upper electrode 40. A predetermined distance X1 is provided, for example, approximately 10 mm from the peripheral edge of the portion 48, and aluminum as a conductive member is exposed in the peripheral edge X2, for example, approximately 20 mm that is approximately the central portion, and they are in electrical contact with each other. Is configured to.

Next, the method of forming the joint portion 48 will be specifically described. , A conductive member 49, as shown in FIG.
For example, as the base material, the protrusion 50 is formed on the surface of the aluminum or aluminum alloy joint 48 side. For example, the height is in the range of 30 to 200 μm, for example, the height 5 is approximately 50 μm.
The convex portion 50 of No. 1 is formed by polishing or the like. At this time, the flatness as the surface roughness of the joint portion 48 is preferably about 10 μm or less in order to maintain the flatness in the subsequent steps. After this step, as shown in FIG. 3B, the surface of the conductive member 49 is covered with the convex portion 50 by 31 to 200.
An insulating layer 53 having a thickness 52 of a predetermined value in the range of μm, for example, about 70 μm, such as aluminum alumite, is formed. Then, as shown in FIG. 3C, for example, the insulating layer 5 has a thickness of 20 μm or more until at least the surface of the protrusion 50 is projected.
3 and the convex portion 50 are polished and the surface of the conductive member 49 on the joint portion 48 side is mirror-finished to have a surface roughness of about 20 μm or less to form the joint portion 48.

When the above-mentioned convex portion 50 is formed by polishing or the like, the flatness as the surface roughness of the joint portion 48 is about 1.
The value of 0 μm or less means that the surface roughness of the side surface of the joint 48 of the conductive member 49 in the mirror finishing step is approximately 20 μm or less so that the finishing is performed with a precision more than double the surface roughness. This is because it becomes difficult to achieve a surface roughness of about 20 μm or less. Further, the reason for finishing the surface roughness to about 20 μm or less in the mirror finishing step is that if the surface roughness is less than or equal to the surface roughness, the familiarity of the joint portion is good, and the joint portion 4 from outside the joint portion 48 is
This is because it is possible to prevent the plasma from entering the inside of the joint 8 and the generation of the plasma in the joint portion 48, and to suppress the corrosive gas, for example, a chlorine-based gas or a fluorine-based gas from entering the joint portion 48. . Further, since an electrical joint portion is provided in the substantially central portion of the joint portion 48 and the insulating layer 53 is formed in the joint portion around the joint portion 48, the above-described plasma intrusion or corrosive gas intrusion is performed. Even if it enters from the peripheral portion of the joint portion, it is suppressed by the insulating layer 53 so that it does not act on the electrical contact portion in the central portion.

Therefore, the bonding side surface of the upper electrode 40 is shown in FIG.
As shown in FIG. 5, the insulating layer 53 is formed so as to be arranged in the central portion 60 where the small hole 44 is provided and the peripheral portion 61, and the joint portion 48 for electrically conducting is arranged between them. The same processing is performed on the joint surface side of the convex portion 45 shown in FIG. 1 with the joint portion 48, and these members are brought into contact with each other and joined by the bolt 46 as shown in FIG.

As shown in FIG. 1, the upper electrode 4
The peripheral portion 70 of 0 is bent in a direction opposite to the plasma generation region in order to prevent plasma or the like from wrapping around the connecting portion 48 or wraparound of corrosive gas. And, to prevent the wraparound of plasma or the like or the wraparound of corrosive gas from acting on the connection portion 48,
A peripheral portion 70 as a bent portion of the upper electrode 40 and the convex portion 4
It is preferable that the gap 70a with the gap 5 is 5 mm or less. Further, the joint portion between the gas diffusion plate 42 and the convex portion 71 provided on the processing container 2 is also configured to be electrically connected to the processing container 2 by the same processing as described above.

When the processing container 2 is composed of, for example, a plurality of members as members that need to be electrically connected to each other as described above, for example, as shown in FIG. Needless to say, the joint portion 74 with the side wall plate 73, the joint portion 75 with the susceptor 7 and the susceptor support 5 and the like may be formed as described above to join the respective members.

Next, the operation of this embodiment configured as described above will be described. First, the upper part of the susceptor 7 in the processing container 2 which is depressurized to a predetermined pressure, for example, equal to or positive pressure of the preparatory chamber (not shown) and is depressurized to about 1 × 10 ⁻⁴ to several Torr. The wafer W is placed on the wafer W, and the electrostatic chuck 13 holds the wafer W on the susceptor 7 side by Coulomb force. Then, a high frequency is applied between the upper electrode 40 and the lower electrode (susceptor) 7 through the pipe lead 22 to generate plasma, and at the same time, a process gas is caused to flow from the upper electrode 40 side into the processing space to perform etching treatment. I do.

Further, since the wafer is excessively heated above a predetermined set temperature by the heat of the plasma, a coolant, for example, liquid nitrogen, is circulated through the cooling jacket 8 of the susceptor support 5 to cool the wafer. Is maintained at −196 ° C., and the cold heat from this is supplied to the wafer W via the susceptor 7 on the upper side, and the wafer W is cooled and maintained at a desired low temperature state. As a result, the wafer W is subjected to low temperature etching. Further, a temperature adjusting heater 2 provided between the cooling jacket 8 and the wafer W.
The temperature at which the wafer W is cooled is adjusted by adjusting the heat generation amount of the wafer W, and the wafer W is cooled to a predetermined temperature, for example, −150 ° C.
Maintain around -100 ° C. By controlling the amount of heat generated by the heater 28 and the flow rate of the coolant in the jacket 8, the wafer temperature can be raised to room temperature or higher, for example, 100 ° C.

Next, the effect of this embodiment will be described. As described above, an electrical joint portion is provided on the joint surface of the members that need to be electrically connected to each other in the substantially central portion of the joint portion 48, and the insulating layer 53 is formed around the joint portion. Therefore, it is possible to prevent plasma from entering the inside of the joint 48 from outside the joint 48, that is, to prevent the generation of plasma in the joint 48, and further to corrosive gas such as chlorine-based gas or fluorine-based gas. Since it is possible to prevent the metal from entering the joint portion 48, it is possible to prevent the joint portion 48 from corroding. As a result, sputtered substances or corrosive substances due to plasma from the joint portion become particles and the processing container 2 It can be prevented from floating inside. And because the particles can be suppressed from floating,
Adhesion to the object to be processed can be prevented and the yield of the object to be processed can be suppressed. In addition, since the electrically conductive joint is not corroded or sputtered, the impedance can be kept stable during electrical conduction. Especially in plasma devices, etc., the impedance matching of the high frequency power source can be stabilized and the impedance fluctuation can be suppressed. However, since the object to be processed can be processed with the same electric power or the same phase, the yield such as the variation in the processing of the object to be processed can be improved.

In the above embodiment, the case where the present invention is applied to the joining portion of the upper electrode portion of the low temperature plasma etching apparatus has been described, but the present invention is not limited to this, and other members are electrically connected. Any device may be used as long as it is a joint between members that needs to be
For example, the present invention can be applied to a prober device for inspecting the electrical characteristics of wafers, LCDs, etc. at low temperatures, a CVD device, and an electron microscope for observing a sample.

[0027]

According to the present invention, it is possible to suppress etching of a joint between conductive members that need to be electrically connected to each other by plasma, and to suppress corrosion by a corrosive gas. Since it is possible to suppress the generation of particles from between, it is possible to suppress the particles from adhering to the object to be processed and improve the yield of the object to be processed.

[Brief description of drawings]

FIG. 1 is a cross-sectional configuration diagram showing an embodiment of a processing apparatus according to the present invention.

FIG. 2 is an enlarged cross-sectional view showing the vicinity of the joint portion in FIG.

[Figure 3]

FIG. 1A is a schematic cross-sectional view showing a process of forming a joint portion in FIG.

2B is a schematic cross-sectional view showing the process of forming the joint portion of FIG. 1. FIG.

FIG. 3C is a schematic cross-sectional view showing the process of forming the joint portion in FIG. 1.

FIG. 4 is a schematic perspective view showing an upper electrode in FIG.

FIG. 5 is a cross-sectional configuration diagram of a conventional processing apparatus.

FIG. 6 is an enlarged cross-sectional view showing the vicinity of a joint portion of a conventional processing apparatus.

[Explanation of symbols]

 1 Etching Device (Processing Device) 2 Processing Container 5 Susceptor Support 7 Susceptor (Lower Electrode) 40 Upper Electrode 48, 74, 75 Junction 47, 53, 60, 61 Insulating Layer W Semiconductor Wafer (Processing Object)

Claims (10)

[Claims] 1. A step of forming a convex portion on a surface joint portion of a conductive member, a step of forming an insulating layer on a surface of the conductive member having at least a convex portion, and removing the insulating layer on the surface of the convex portion. And a step of joining a member to be joined to the surface of the removed convex portion, the method for forming a joined portion. 2. A step of forming a convex portion on a surface of a conductive member, a step of forming an insulating layer having a thickness covering the convex portion on a surface of the member, and at least until the surface of the convex portion protrudes. And a step of polishing the insulating layer and the convex portion, and mirror-finishing the surface of the member on the side of the joint portion, the method for forming the joint portion. 3. A method of joining members for electrically conducting between members forming a processing apparatus for heat-treating or plasma-treating an object to be processed, wherein at least one of the members has a convex portion. A step of forming an insulating layer on the surface of the member on the side of the joint portion, a step of removing the insulating layer on the surface of the convex portion, and a member to be joined to the surface of the convex portion exposed in this step. And a step of bringing the members into contact with each other. 4. A method of joining members for electrically conducting between members forming a processing apparatus for heat-treating or plasma-treating an object to be processed, the method comprising: A step of forming a convex portion, a step of forming an insulating layer having a thickness that covers the convex portion on the surface of the bonding portion side of those members, and polishing the insulating layer to the surface of the convex portion,
Furthermore, the step of polishing the insulating layer and the convex portion at the same time, mirror-finishing the surface of the member on the joint side, and bringing the convex portions of the respective members into contact with each other A method for joining members of a device. 5. The base material of the member is made of aluminum or aluminum alloy, the method for forming a joint according to claim 1, the method for forming a joint according to claim 2, or the treatment device according to claim 3. The joining method between members or the joining method between members of the processing device according to claim 4. 6. The method for forming a joint according to claim 1, the method for forming a joint according to claim 2, or the method for joining between members of a processing apparatus according to claim 3, wherein the insulating layer is alumina. Alternatively, the joining method between the members of the processing apparatus according to claim 4. 7. The method for forming a joint according to claim 1 or the method for forming a joint according to claim 2, wherein the height of the protrusion has a predetermined value in the range of 30 to 200 μm. The method for joining members of the processing apparatus according to claim 3, or the method for joining members between members of the processing apparatus according to claim 4. 8. The insulating layer has a thickness of 31 to 200 μm.
5. A method for forming a joint according to claim 1, a method for forming a joint according to claim 2, or a method for joining between members of a processing apparatus according to claim 3, or claim 4.
Method for joining members of the processing device of the above. 9. The method for forming a joint according to claim 1 or the method for forming a joint according to claim 2, wherein the convex portion is formed substantially at a center of a surface of the member on the joint portion side. A method for joining members of the processing apparatus according to claim 3 or claim 4
Method for joining members of the processing device of the above. 10. The method for forming a joint portion according to claim 2, or the joint method for joining the members of the processing apparatus according to claim 4, wherein the mirror finish has a roughness of about 20 μm or less.