JPS6325500B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a plasma processing method used for etching and cleaning semiconductor wafers used in the manufacture of chips forming large integrated circuits such as LSIs or VLSIs, or for ashing (ashing and peeling) photoresist layers on wafer surfaces. Among processing apparatuses, the present invention particularly relates to a vertical automatic plasma processing apparatus in which a plasma generation chamber is installed vertically.

Generally, in order to manufacture chips with large integrated circuits such as LSIs, an insulating film, a semiconductor film, or a metal film created on a conductive wafer that is not covered with a resist film with a fine pattern formed on the semiconductor wafer is used. It requires an etching step, a cleaning step for the film, and an ashing step to remove the resist film used for etching from the wafer surface.

Conventionally, each of the above steps has been carried out by wet processing using various liquid chemicals such as inorganic acids and organic solvents. Another problem is that machining accuracy is low. Particularly in recent years, with the development of ultra-LSIs, patterns have become increasingly finer, and it has become impossible to use conventional wet processing to manufacture such ultra-LSIs.

For this reason, there is currently a shift to dry processing using plasma with high processing accuracy, and various plasma processing apparatuses for performing this dry processing have been proposed.

However, many plasma processing devices are simply equipped with a chamber for plasma generation.
Wafers are moved in and out of the chamber exclusively by hand.

For example, wafers are taken out one by one from an unprocessed wafer storage cassette and transferred to a wafer jig made of quartz or aluminum using tweezers. For this reason, production yields are extremely low due to wafer chips, cracks, dropping due to poor holding, and contamination.Furthermore, as in recent years, wafer diameters have increased to 4.
As the size increases from 1 inch to 5 inches to 6 inches, the above-mentioned disadvantages increase. Furthermore, since the temperature is high during plasma processing, manual removal after processing must be avoided, resulting in extremely low work efficiency.

As an automatic plasma processing apparatus that eliminates such disadvantages, there is an apparatus disclosed in Japanese Patent Application Laid-Open No. 53-90870.
This device has an extremely complex structure, and the plasma generation chamber is installed horizontally. This increases the area occupied by the device itself,
It is not possible to make it more compact.

In view of the above-mentioned conventional technical problems, the present inventors have created the present invention to effectively solve the problems. can be processed automatically,
Another object of the present invention is to provide a vertical automatic plasma processing apparatus that can be made compact.

In order to achieve such an object, the present invention arranges a plasma generation chamber vertically within an apparatus main body, and a wafer holder capable of holding a large number of wafers can be freely inserted into and removed from the plasma generation chamber. At the same time, the first conveying member takes out the wafers one by one from the wafer storage cassette and sends them out, while the second conveying member is able to take out the wafers one by one and move them toward the wafer holder.
The apparatus is configured to send out a conveying member, and then feed the wafer into the wafer holder by a second conveying member, wherein the leading end of the first conveying member is located near the base end of the second conveying member. Its gist is:

A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is an overall perspective view of a vertical automatic plasma apparatus according to the present invention, and numeral 1 in the figure is a roughly box-shaped apparatus main body. A cylindrical plasma generation chamber 2 made of quartz is arranged in the device main body 1 in a vertical direction, that is, with the axis of the chamber 2 in the vertical direction.The upper end of the chamber 2 is closed and the lower end is open. By doing so, the semiconductor wafer 3 is loaded into and taken out from the chamber 2 through the opening. Further, an electrode plate is fixed to the outer periphery of the chamber 2, and a high frequency power source 4 provided in the main body 1 applies high frequency waves.

In addition, an overhang 5 is attached to the lower front half of the main body 1, and various operation buttons 7 are provided on the upper surface 6 of this overhang 5.
... are attached, and storage cassettes 8, 8 capable of storing 25 semiconductor wafers 3 are provided at the left and right ends of the upper surface 6. This storage cassette 8 is made up of two plates 8 made of aluminum or Teflon.
a, 8a are opposed to each other and their upper ends are connected by rods 8b, 8b. As shown in FIG. As the storage cassette 8 moves, the storage cassette 8 moves downward into the overhang 5 through the hole 10 formed in the upper surface 6, and lifts upward from the overhang 5.

The inner surface of the plate 8a constituting the storage cassette 8 is provided with protrusions 11 at regular intervals in the horizontal direction, as shown in FIG. The end is designed to lock.

Further, an opening 12 extending in the left-right direction is formed in the center of the upper surface 6 of the overhang, and a pair of first conveying members 13, 13 are disposed within this opening 12.
That is, the conveying member 13 is constituted by an endless belt, the base end 13a of which is located below the storage cassette 8, and the distal ends 13b, 13b of the respective conveying members 13, 13 are spaced apart from each other at the center of the upper surface 6. and facing each other. Further, the upper surface of the endless belt, which is the conveying member 13, protrudes slightly above the upper surface 6 of the overhanging portion, so that when the storage cassette 8 is lowered, the lowest wafer 3 is placed on the endless belt.

Further, an opening 14 is formed in the upper surface 6 of the overhanging portion and extends rearward and is continuous with the opening 12, and the base end portion is located within the opening 14 between the tip portions 13b, 13b of the conveying members 13, 13, A second conveying member 16 is provided, the tip of which enters into the main body 1 through an opening 15 formed in the front surface of the main body 1.

The second conveyance member 16 is composed of an elevating member 17 and an arm member 18, and the elevating member 17 is approximately plate-shaped, and its base end is connected to the first conveyor as shown in FIGS. 2 and 4. It is located within a channel-shaped support block 20 that supports the pulleys 19, 19 at the tips of the members 13, 13, and its lower surface is connected to the support block 2.
It is fixed to a rod 22 of a cylinder unit 21 disposed below 0, and is moved up and down by the operation of the cylinder unit 21, and when the rod 22 is retracted, the upper surface of the elevating member 17 is in the first conveying position. It is positioned slightly lower than the upper surface of the member 13. A window 23 is bored at the base end of the elevating member 17.
3 is fitted with a roller 24 so that the wafer 3 transferred on the first conveying member 13 can be easily transferred onto the elevating member 17.

Also, endless belts 2 are provided on both sides of the elevating member 17.
5 and 25, and lift the wafer 3 to the lifting member 17.
The material is transported along the top surface of the container.

Arm members 18, 18 are provided close to the outside of the endless belts 25, 25. As shown in FIG. 2, the arm member 18 has a rod-shaped portion 18b extending from the upper end of a rectangular base end 18a, and a caster 26 attached to the lower end of the base end 18a.
It is made movable on the guide rail 27 by.

Further, as shown in FIG. 2, two guide rods 28, 28 are provided on the bottom surface of the main body 1,
8 and 28, the lid 29 of the plasma generating chamber 2 is slidably inserted therein. and lid body 2
A gear 31 fitted into the lower end of the rod 30 is screwed and inserted into the gear 30.
and the gear 33 of the motor 32 fixed to the bottom of the main body 1.
The lid body 2 is engaged with the lid body 2 by driving the motor 32.
9 is moved up and down along guide rods 28, 28.

Furthermore, a wafer holder 3 is provided on the upper surface of the lid 29.
4 have been set up. This wafer holder 34 has four
Book rods 34a, 34b, 34c, 34d,
The rods 34a and 34b are located at both ends of the base of the trapezoid when viewed from above, and the rods 34c and 3
4d has a shape located at both ends of the upper side of the trapezoid. and each rod 34a, 34b, 34
In this embodiment, 50 grooves 35, into which the ends of the wafer 3 fit, are formed at equal intervals in the vertical direction on the inner sides of the grooves 34c and 34d. Thus, the wafer 3 placed between the tips of the arm members 18, 18 is fed into the wafer holder 34 by the movement of the arm members 18, 18, and its end is placed in the groove 35... By being locked, the wafer 3 is held by the wafer holder 34.

The operation of the vertical automatic plasma apparatus constructed as described above will be described below.

First, when the left cassette 8 containing 25 wafers 3 is lowered slightly, the lowest one of the wafers 3 stored in the cassette 8 is placed on the first transport member 13. Then, it is sent out by the conveying member 13. The wafer 3 that has been transported to the tip end 13b of the transport member 13 is transferred onto the elevating member 17 that constitutes a part of the second transport member 16. Then, the cylinder unit 21 is actuated by the limit switch, the elevating member 17 rises slightly, and at the same time, the endless belts 25, 25 are driven to transport the wafer 3 to the tip of the elevating member 17.

When the wafer 3 reaches the tip of the elevating member, the limit switch activates the endless belts 25, 25.
stops, and then the elevating member 17 descends slightly to its original position. Then, the wafer 3 is transferred to the tips of the arm members 18, 18, and the arm members 18, 18 further move toward the wafer holder 34. As a result, the wafer 3 is attached to the wafer holder 3.
4, and the rods 34a, 34 of the holding body
The ends thereof are locked in grooves 35 formed in b, 34c, 34d. In this case, since the wafer holder 34 is located at the lowest position, the wafer 3 is held at the uppermost stage of the wafer holder 34.

Next, by driving the motor 32, the wafer holder 34 is raised by one step, that is, by one space between the grooves 35..., the wafer 3 is separated from the tips of the arm members 18, 18, and the arm members are moved back to their original positions. Then, the device returns to its initial state.

Thereafter, the left cassette 8 is further lowered by one stage to deliver the second wafer, and this wafer is transferred to the second wafer holder 34 by the same action as described above.
It is held in the groove of the step. In this way, the wafers 3 are sequentially fed into the wafer holder 34, and all the wafers in the left cassette are transferred to the holder 3.
4, the wafers in the right cassette 8 are held in the wafer holder 34 in the same way, and finally 50 wafers are placed in the wafer holder 34.
send to.

Then, the lid body 29 is further driven by the motor 32.
After the chamber 2 is raised, the lower end opening of the plasma generating chamber 2 is closed and the inside is sealed, the chamber 2 is evacuated by a vacuum pump and plasma is generated to perform etching, cleaning or ashing processing.

After plasma treatment for a predetermined period of time,
Drive the motor 32 and move the wafer holder 3 until the lowest wafer 3 in the wafer holder 34 is at a position slightly higher than the upper ends of the arm members 18, 18.
4 to descend. Next, arm members 18, 18
is moved in the direction of the holder 34 so that the tip of the arm member is positioned directly below the wafer at the lowest stage. Then, by further driving the motor 32, the holder is lowered, the wafer is placed on the arm member, and the wafer is stored in the cassette 8 by the reverse operation. Thereafter, the plasma treatment is completed by the same action.

It should be noted that the above is just one embodiment of the present invention,
The present invention is not limited to the above. For example, in the illustrated example, the second conveying member 16 is connected to the elevating member 17.
Although the second conveying member is composed of two members, ie, the arm member 18 and the arm member 18, it is also possible to construct the second conveying member by a single member that performs both the lifting operation and the moving operation toward the wafer holder.

Further, although an endless belt is shown as the first conveying member, the wafers are not limited to this, and the wafers may be sent out by a swing motion.Furthermore, a motor and a rod may be combined as the lifting means instead of using a cylinder. You may also do so.

As is clear from the above description, according to the present invention,
A wafer holder capable of holding a large number of wafers is provided so as to be freely inserted into and removed from a plasma generation chamber arranged vertically within the main body of the apparatus, while a cassette capable of storing a large number of wafers is installed in the main body of the apparatus, A first transport member for taking out and transporting the wafers stored in the cassette is provided in the main body of the apparatus, and further, a base end is located near the tip of the first transport member and is movable in the direction of the wafer holder. Since the wafer is fed into the wafer holder by the second conveying member, the wafer can be reliably loaded into the chamber without manual work, and work efficiency can be greatly improved. There is no risk of damaging the wafer during work, and product yield can be improved.

Since the mechanism of the present invention is extremely simple and the chamber is vertical, it has great effects such as making the entire device more compact.

[Brief explanation of the drawing]

The drawings show a preferred embodiment of the present invention, and FIG. 1 is an overall perspective view of a vertical automatic plasma processing apparatus according to the present invention, FIG. 2 is a perspective view showing the internal mechanism of the apparatus, and FIG. This figure is a side view showing a part of the wafer storage cassette, and FIG. 4 is a front view showing the main part of the wafer transport mechanism. In the drawings, 1 is the main body of the apparatus, 2 is a plasma generation chamber, 3 is a wafer, 8 is a wafer storage cassette, 13 is a first transport member, 16 is a second transport member, and 34 is a wafer holder.

Claims (1)

[Claims] 1 A plasma generation chamber arranged vertically inside the apparatus main body, a wafer holder that can be freely inserted into and removed from the chamber via an elevating mechanism, and a wafer storage cassette in which wafers are taken out one by one and the wafers are In the vertical automatic plasma processing apparatus, the wafer holder is comprised of a plurality of rods extending vertically, and these rods have end portions of the wafer spaced apart in the vertical direction. A vertical automatic plasma processing apparatus characterized in that a groove into which the wafer holder is fitted is formed, and the transfer member is provided with an arm member capable of moving forward and backward into a space surrounded by a rod of the wafer holder.