JPH0660997A - Vacuum chamber of plasma device - Google Patents

Abstract

(57) [Abstract] [Purpose] Vacuum chamber 1 used in plasma equipment
It is possible to perform the maintenance of 00 easily and quickly. [Structure] An airtight housing 101 constituting a vacuum chamber 100 is separated into an upper side 103 and a lower side 10 which can be separated.
4 is configured so that an opening for maintenance can be formed in the airtight vacuum chamber 100, and the upper side 103 and the lower side 104 are provided with sealing means 107 and 106 having airtightness. It is provided so that it can be connected and separated.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a vacuum chamber of a plasma device.

[0002]

2. Description of the Related Art Conventionally, there has been provided a plasma device which generates plasma between parallel plate electrodes arranged in a vacuum chamber and performs a predetermined process on various objects to be processed. For example, in a semiconductor manufacturing process, various processes such as an etching process, an ashing process, and a film forming process are performed on a semiconductor wafer as an object to be processed by a plasma device.

The vacuum chamber of this plasma apparatus has a vacuum chamber formed by an airtight housing, and parallel plate electrodes for plasma generation are vertically arranged in the airtight housing. . Then, plasma is generated by the discharge between the electrodes, and thereby the object to be processed is processed. The reaction product generated by the plasma treatment is exhausted to the outside through an exhaust path provided in the vacuum chamber.

[0004]

However, the above-mentioned reaction product adheres to each part in the vacuum chamber including the exhaust path. The reaction product (deposition) that is adhered and laminated may peel off from the adhesion site after a predetermined time elapses, and it may become particles and adhere to the surface of the object to be treated. Therefore, in a normal plasma device, each part is regularly, for example, once every few days.
Maintenance is carried out such as removal and removal, cleaning by immersion in liquid or rubbing, and replacement. When performing such maintenance work, it takes a lot of time and labor because the inside of the device has a complicated and narrow structure, and the production line must be stopped. There is a problem that it takes a considerable amount of time to restart.

[0005] Therefore, an object of the present invention is to provide a plasma device capable of easily and quickly maintaining a vacuum chamber.

[0006]

In order to achieve the above object, the first means according to the present invention comprises an airtight housing which forms a vacuum chamber, and a plasma is provided in the airtight housing. In a vacuum chamber of a plasma device in which a parallel plate electrode for generation is arranged, the airtight housing is configured in a divided structure including an upper side and a lower side, and an upper side of the airtight housing is formed. The lower side has a configuration that is provided so as to be connectable / separable via a sealing means having airtightness. The second means according to the present invention is the device of the first means, wherein the upper side and the lower side of the airtight housing are connected so as to maintain conductivity.

[0007]

In the first and second means having such a structure, when performing maintenance on the vacuum chamber, first, the upper side and the lower side of the airtight housing which constitutes the vacuum chamber are separated, and An opening for maintenance is formed in the airtight vacuum chamber.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment in which the present invention is applied to a magnetron plasma etching apparatus will be described in detail below with reference to the drawings.

As shown in FIG. 3, the magnetron plasma etching apparatus includes a vacuum chamber 100 for a process, and both sides of the vacuum chamber 100 are provided.
The load lock chambers 130, 130 are connected to each other, and each of the load lock chambers 13 is connected.
Wafer cassette standby sections (loading / unloading sections) 90 and 91 are connected to 0 and 130, respectively. That is, the vacuum chamber 1
00 is the two load lock chambers 130, 130
The unprocessed object is carried in from one of the load lock chambers 130, and the object is carried out to the other load lock chamber 130. Each of the facing walls of the load lock chamber 130 and the vacuum chamber 100 is formed with an opening through which an object to be processed is formed and connected in an airtight manner, and the opening on the load lock chamber 130 side has a gate block. 16 is provided so as to be opened and closed. The connection structure between the vacuum chamber 100 and the load lock chamber 130 will be described later.

In the loading section 90 and the unloading section 91, a wafer cassette WC holding a plurality of semiconductor wafers as objects to be processed.
Are arranged so that they can be carried in and out by a robot (not shown). The gate block 16 is configured to hermetically block an opening formed in a partition wall that partitions the loading / unloading sections 90 and 91 and the load lock chambers 130 from each other. Each wafer cassette WC can store, for example, 25 semiconductor wafers W.

A handling device 8 is provided in each loading chamber 130, and the semiconductor wafer W is vacuum chamber 100 by the handling device 8.
It is designed to be carried in or out. Further, one end of the exhaust pipe 131 is connected to each load lock chamber 130.
Is communicated with the inside of each of these exhaust pipes 131
The other end of is connected to the suction port of an exhaust pump (not shown).

Further, as shown in FIG. 2, the vacuum chamber 100 contains an RIE type etching apparatus. The housing 101 of the vacuum chamber 100 forms a vacuum chamber so as to cover the lower frame 32 from the upper side in an airtight manner.
The first top plate 102 is grounded to form an upper electrode. On the other hand, the upper and lower mounting tables 5 that constitute the lower electrode
2, 54 are arranged on the lower frame 32 via an insulating layer 56, and an RF power source 55 is connected to the lower mounting table 54. From this RF power source 55, for example, a high frequency of 13.56 MHZ. A counter electrode is formed between the counter electrode and the upper electrode 102 when power is supplied.

As shown in FIG. 1, the side wall of the airtight housing 101 has an upper side wall 103 and an upper side wall 103.
It has a divided structure including a lower side wall 104. The connection surfaces of the upper side wall 103 and the lower side wall 104 are each given a predetermined surface finish.
3, 104 are abutted so as to maintain airtightness and conductivity. Further, the contact portion has an O as a sealing means.
The ring 105 is inserted and tightened by four fixing bolts 106 so that the two 103, 104 are pressed against each other. Due to the pressing force of the fixing bolt 106, the above-mentioned airtightness and conductivity are well secured.
If the fixing bolts 106 are removed, the upper side wall 1
03 is pulled out upward.

The upper top plate 102 is placed so as to seal the upper end opening of the upper side wall 103. On the mounting portion of the upper top plate 102, an O-ring 1 as a sealing means
07 is mounted, and one end portion of the upper top plate 102 is rotatably supported by a pair of arms 108 extending from the lower side wall 104 via pins 109. As a result, the upper top plate 102 is configured to rotate between the closed position shown in FIG. 2 and the open position shown in FIG.

The semiconductor wafer W is mounted and fixed on the upper surface of the upper mounting table 52. As the mounting and fixing means, for example, an electrostatic chuck method is adopted. The upper mounting table 52 is detachably fixed to the lower mounting table 54. The reason why the upper and lower mounting bases 52 and 54 are separable is that the lower mounting base 54 connected to the RF power supply 55 is maintenance-free and only the contaminated upper mounting base 52 can be replaced. It is configured in. The lower mounting table 54 includes the semiconductor wafer W on the upper mounting table 52.
A heater 53 for finely adjusting the temperature is embedded, for example. Further, a heater 31 for setting a temperature for making it difficult for reaction products to adhere to the inner wall of the vacuum chamber 100.
Is embedded in the lower part of the housing 101, for example.

The side peripheral surfaces and the bottom surfaces of the upper mounting table 52 and the lower mounting table 54 are covered with an insulating layer 56,
Only the upper surface of the upper mounting table 52 is exposed in the process atmosphere. An O-ring 40 is inserted between the upper mounting table 52 and the insulating layer 56, and a high vacuum state gap is formed between them. The side peripheral surfaces of the upper and lower mounting tables 52 and 54 and the inner peripheral surface of the insulating layer 56 are both mirror-finished.

Around the semiconductor wafer W mounted and fixed on the upper surface of the upper mounting table 52, there is provided a baffle plate 110 for adjusting the pressure of the process atmosphere in the vacuum chamber and keeping the vacuum pressure constant. Has been done. The baffle plate 110 is formed into a substantially L-shaped cross section, the base side of which is bolted to the inner peripheral surface of the upper side wall 103 of the housing 100 and which extends from the substrate side to the radially inner peripheral side. A large number of pressure adjusting ports 11 are provided on the protruding disk-shaped portion.
0a is formed through.

Immediately below the insulating layer 56, the cooling jacket 2 is provided.
0 is provided. Liquid nitrogen is housed inside the cooling jacket 20. This cooling jacket 2
The inner wall of the bottom portion of No. 0 is formed with a porous material for nucleate boiling so that the liquid nitrogen in the jacket 20 can be maintained at a temperature of -196 ° C. The temperature of the semiconductor wafer W on the upper mounting table 52 is controlled by the cooling jacket 20 and the heater 53 during the processing, for example, −60 ° C.
It is cooled to the following temperature.

A plurality of insulating members 22 are provided in the cooling jacket 2.
It is inserted between 0 and the bottom 32b of the lower frame, and a second gap 23 is formed between them. on the other hand,
An inner cylinder 32a extends upward from the bottom 32b of the lower frame, and the cooling jacket 20 and the insulating layer 56 are hidden from the process atmosphere by the inner cylinder 32a. Further, an O-ring 44 made of fluorocarbon resin such as Teflon is inserted between the insulating layer 56 and the inner cylinder 32a, and a third gap 24 is formed. The outer peripheral surface of the insulating layer 56 and the inner peripheral surface of the inner cylinder 32a are mirror-finished.

As shown in FIG. 2, the plurality of insulating members 22 supporting the cooling jacket 20 are separated from each other. Therefore, the second gap 23 and the third gap 24 described above communicate with each other. The third gap 24 has an insulating layer 56.
Also, the narrower the narrower the better, as long as the cooling jacket 20 and the inner cylinder 32a do not come into close contact with each other.

As shown in FIG. 2, the process atmosphere in the vacuum chamber surrounded by the housing 100 is the first exhaust pipe 34.
It is designed to be evacuated through. On the other hand, the second and third gaps 23, 24 are evacuated through the second exhaust pipe 36. For example, a wafer W on the upper mounting table 52 is formed so that a horizontal magnetic field orthogonal to the electric field, that is, parallel to the wafer surface is formed near the surface of the wafer.
A disk 124 having a permanent magnet 122 on its lower surface is disposed above the upper top plate (upper electrode) 102 at a position facing with. At the top of this disk 124, the motor 12
6 shaft 128 is attached to the disk 124
When the permanent magnet 122 attached to the wafer W is rotated by the motor 126, a magnetic field parallel to the surface of the wafer W is formed in the vicinity of the wafer W. The magnetic field may be composed of an electromagnet.

The etching gas in the vacuum chamber 100 is exhausted through the exhaust pipe 34, so that the internal pressure of the vacuum chamber 100 is low, for example, 10 ^-2 to 10 ^-3.
The pressure is reduced to the range of Torr. The etching gas is turned into plasma between the opposing electrodes. In the magnetron plasma etching, the interaction between the magnetic field and the electric field of the plasma sheath orthogonal to the magnetic field causes the electrons to perform a cycloidal motion, increasing the number of times the electrons collide with the molecules and are ionized. Therefore, a high etching rate can be obtained even with the low pressure as described above.

Next, the connecting portion between the load lock chamber 130 and the vacuum chamber 100 will be described.

The vacuum chamber 100 and the load lock chamber 130 are connected and fixed by a fixing bolt 170, and a slide seal mechanism is provided at the connecting portion of the transfer path of the semiconductor wafer W. That is, first, in the vacuum chamber 100 and the load lock chamber 130, openings that form a transfer path for the semiconductor wafer W are formed. Vacuum chamber 100
The side opening is provided in the upper side wall 103, and a convex connecting wall 111 protruding toward the load lock chamber 130 side is provided in the opening forming portion. A slide ring 112 is provided on the outer peripheral portion of the connection wall 111.
Is reciprocally slidably mounted, and an O-ring for sealing is fitted in an annular groove recessed in the inner peripheral portion having the sliding surface of the slide ring 112. The front end surface (the left end surface in the drawing) of the slide ring 112 faces the periphery of the opening of the load lock chamber 130,
The slide ring 112 is configured to come into contact with and separate from the slide ring 112 as the slide ring 112 slides back and forth. Further, an O-ring for sealing is arranged on the front end surface of the slide ring 113 so that sealing is performed when the slide ring 113 is brought into contact with the load lock chamber 130.

On the other hand, an eccentric cam mechanism 113 constituting a lock mechanism is arranged on the rear end surface (right end surface in the figure) of the slide ring 112. This eccentric cam mechanism 113
Is equipped with an eccentric cam axially supported between the rear end surface of the slide ring 112 and the upper side wall 103 of the vacuum chamber 100, and the slide ring 112 is rotated by using a predetermined rotating jig. It is configured to slide back and forth.

Further, as described above, the gate 16 for sealing / opening the opening is provided on the chamber inner surface side of the opening provided on the load lock chamber 130 side. The gate 16 slides on the inner surface side of the chamber via an O-ring for sealing, and is configured to reciprocate by a drive mechanism (not shown).

The operation of the embodiment apparatus having such a configuration will be described below. In the RIE type plasma etching apparatus of the present embodiment, the upper top plate 102 forming the upper electrode is grounded, and the upper and lower mounting table 5 forming the lower electrode is formed.
The counter electrode is formed by supplying RF power to 2, 54. Further, by rotating the permanent magnet 122 above the upper top plate 102 at a position facing the semiconductor wafer W and forming a magnetic field parallel to the surface of the permanent magnet 122 in the vicinity of the semiconductor wafer W, a magnetron etching treatment atmosphere is created. Is forming. Then, an etching gas is introduced while the inside of the vacuum chamber 100 is evacuated, and plasma is generated by the etching gas between the opposed electrodes.

In performing the magnetron plasma etching, the semiconductor wafer W to be processed is cooled by the cooling jacket 20 to a temperature of, for example, about -60 ° C. For this reason, the cooling jacket 20 has a -1
Liquid nitrogen at 96 ° C is supplied, and semiconductor wafer W
Is cooling. Here, when the semiconductor wafer W is cooled, ideally, heat is exchanged only between the cooling jacket 20 and the semiconductor wafer W, and the heat exchange with other members is suppressed as much as possible to achieve an efficient semiconductor wafer. It is possible to cool W. Fine adjustment of the wafer temperature is executed by adjusting the temperature of the heater 53. By doing so, it is possible to prevent the lower chamber from being cooled, and it is also possible to prevent reaction products from adhering to this low temperature region.
A gas such as an inert gas or hydrogen is introduced into the contact surfaces of the upper and lower mounting tables 52, 54 to improve heat conduction.

On the other hand, when the generated plasma is stable, the etching gas (for example, CHF ₃ , CF ₄ , CCl ₄ etc.) is supplied from the outlet of the processing gas supply passage.
As a result, a plasma etching reaction is induced, and a desired etching process is performed depending on the selection ratio between the resist (not shown) deposited on the semiconductor wafer W and the base (eg, SiO ₂ ). At this time, as described above, the permanent magnet 12
Since the plasma density is locally concentrated by the magnetic field of 2, the etching process is performed very effectively, and the part where the plasma is concentrated is rotated, so that the etching process is performed over the entire surface of the wafer W. It will be executed uniformly.

After the desired etching process is completed, the inside of the vacuum chamber 100 is set to a safe atmosphere,
The wafer carry-out port of the vacuum chamber 100 is opened, and the processed semiconductor wafer W is held by an appropriate handling device 8 and discharged from the discharge port. After that, the above-described operation is repeated, so that the dry etching process for the semiconductor wafer W is single-wafer processed.

When CHF ₃ is used as an etching gas for such a plasma etching process to etch SiO ₂ as a base covered with a resist, a reaction product is generated by a chemical reaction such as the following formula. . 4CHF ₃ + 3SiO ₂ → 4CO + 3SiF ₄ + 2H ₂ O The reaction product at this time is exhausted to the outside through an exhaust path provided in the vacuum chamber 100, and on the way to each site in the vacuum chamber 100. Attach as a deposition. In particular, in the region directly above the baffle plate 110 arranged around the semiconductor wafer W, the amount of deposition adhered to the baffle plate 110 tends to be considerably large. The deposited and stacked deposition may be peeled off from the deposition site after a lapse of a predetermined time, and there is a possibility that the deposition becomes particles and is deposited on the surface of the target object. Therefore, maintenance inside the device is performed.
In this maintenance, each part is periodically removed, for example, once every two or three days and cleaned by liquid immersion, rubbing, or the like, or replaced.

In carrying out such maintenance work, first, the upper top plate 102 is opened by rotating it to the upper open position as shown in FIG. 1, and then the upper side wall 103 and the lower side wall 104 of the housing 101 are opened. Loosen and remove the fixing bolt 106 that is tightened and connected. Further, the eccentric cam of the eccentric cam mechanism 113 is rotated to make the slide ring 112 slidable, and the slide ring 112 is moved toward the vacuum chamber 100 side and separated from the load lock chamber 130 side. As a result, the upper side wall 103 of the housing 101 is ready to be pulled out in the directly upward direction. By removing the upper side wall 103 of the housing 101, an opening for maintenance is formed in the vacuum chamber 100, and the maintenance work described above can be efficiently performed. That is, if the work is performed through the maintenance opening, the inside of the complicated and narrow structure can be easily reached, and the liquid can be easily immersed in each part.

In particular, in this embodiment, since the dividing portion of the upper side wall 103 and the lower side wall 104 is set at the lower position of the baffle plate 110, the cleaning and maintenance of the baffle plate 110 having a large deposition amount is good. Can be carried out.

The dividing portion between the upper side wall 103 and the lower side wall 104 in the above embodiment is set at a position slightly lower than the conveying path, but the dividing portion can be set at a position above the conveying path. . In this case, the slide seal mechanism such as the slide ring 112 is unnecessary.

The present invention is not limited to the plasma etching apparatus in the above-mentioned embodiment, and any apparatus can be applied as long as it is a plasma apparatus having a vacuum chamber such as a CVD sputtering apparatus. it can.

[0036]

As described above, according to the present invention, the vacuum chamber can be easily and quickly maintained, and the productivity can be improved by preventing troubles such as the stop of the production line. .

[Brief description of drawings]

FIG. 1 is an external perspective view showing a maintenance execution state of a plasma device according to an embodiment of the present invention.

FIG. 2 II-II in FIG. 3 showing the structure of a vacuum chamber
It is a longitudinal cross-sectional view along a line.

FIG. 3 is a schematic plan view showing the overall structure of the plasma device.

[Explanation of symbols]

 100 Vacuum Chamber 101 Housing 102 Upper Top Plate 103 Upper Sidewall 104 Lower Sidewall 113 Eccentric Cam Mechanism 130 Load Lock Chamber W Semiconductor Wafer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H01L 21/302 B 9277-4M

Claims (2)

[Claims] 1. A vacuum chamber of a plasma apparatus, comprising a hermetically sealed housing forming a vacuum chamber, wherein parallel plate electrodes for plasma generation are arranged in the hermetically sealed housing. The housing has a split structure consisting of an upper side and a lower side, and the upper side and the lower side of the airtight housing are provided so as to be connectable / separable via a sealing means having airtightness. A vacuum chamber of a plasma device, which is characterized in that 2. The vacuum chamber of the plasma apparatus according to claim 1, wherein the upper side and the lower side of the airtight housing are connected so as to maintain conductivity. Vacuum chamber.