JP2000077389A - Plasma processing method and apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for processing a plasma which can prevent cracking or break of a wafer even in the case that the wafer is made of material easy to crack. SOLUTION: This device is equipped with a cassette lifting stage 5 where a tray cassette 1 is arranged under a wafer cassette 3, a handling arm 6 on the open air side which can carry both a wafer 4 and a tray 2, and a combination station 7 which has a function for deciding the rotational position of the tray 2 so that the pushup pin 9 for pushing up the wafer 4 at delivery of the wafer and a wafer centering function for performing centering so that it may put the wafer 4 at the center of the tray 2. Then, the wafer 4 is put on the tray 2 and transfer and processing are performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a plasma processing apparatus used for manufacturing a semiconductor device or a liquid crystal display device (LCD).

[0002]

2. Description of the Related Art As shown in FIG. 6, a conventional plasma processing apparatus includes an etching chamber A, load lock chambers B and C, and
And handling arms D and E provided in the load lock chambers B and C, a wafer cassette F for storing processed wafers, and a wafer cassette G for storing unprocessed wafers H.
And a handling arm I on the atmosphere side.

In the above configuration, the wafer H is taken out of the wafer cassette G by the handling arm I on the atmosphere side, carried into the load lock chamber B, and delivered to the handling arm D. Thereafter, the inside of the load lock chamber B is evacuated, and after the evacuation is completed, the wafer H is carried by the handling arm D into the etching chamber A which is always in vacuum. A gas containing chlorine as a main component is introduced into the etching chamber A, and high frequency power is applied to perform plasma etching of the metal wiring film. After the etching, the wafer H is evacuated by the handling arm E to the load lock chamber C. To be carried out. Thereafter, the load lock chamber C is filled with nitrogen, and after reaching atmospheric pressure, the wafer H is stored in the wafer cassette F by the handling arm E.

[0004]

However, in the above-described conventional configuration, when a piezoelectric material or the like is used as the wafer H, the piezoelectric material itself is not only a crystal that is easily broken, but also has a thermal deformation and an electrostatic effect due to the influence of etching. There has been a problem that the risk of wafer destruction due to adsorption or the like is very high.

In addition, when aluminum pattern etching is performed, there is a problem that corrosion occurs after etching.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a plasma processing method and apparatus which can prevent cracking and wafer destruction even in the case of a material in which a wafer is easily broken, and can prevent corrosion. .

[0007]

A plasma processing method according to the present invention includes a step of placing a wafer on a tray, and a step of carrying the plasma processing by transporting the wafer loaded on the tray into a processing chamber. In addition, the wafer can be prevented from cracking by carrying and processing the wafer placed on the tray.

When the wafer is placed on a tray without being exposed to the atmosphere after the plasma processing, and both are sucked and rotated, and rinsed with pure water and a chemical solution, the aluminum pattern and the like can be etched even when etching. Corrosion can be prevented.

Further, the plasma processing apparatus of the present invention comprises a cassette stage in which a tray cassette is arranged below a wafer cassette, an atmosphere-side handling arm capable of transporting both the wafer and the tray, and a pin for pushing up the wafer when transferring the wafer. A combination station having a tray position determination function for ascending and a function of centering the wafer so that the wafer can be placed at the center of the tray, wherein the wafer is placed on the tray for carrying and processing, The above method can be implemented to prevent the wafer from cracking.

When the processing is performed by circulating the number of processing chambers plus one tray between each processing chamber and the combination station, the above processing can be performed at a low cost with the minimum number of trays.

Further, if the wafer size can be switched only by changing the tray cassette, the positioning at the combination station when the wafer size is switched, the setting of the recipe, and the setting of the position for transferring the wafer are automatically performed. be able to.

Further, if a rinsing chamber for rinsing with a pure water and a chemical solution is provided by using a spin chuck capable of adsorbing both the tray and the wafer and rinsing with a pure water, a chemical solution, etc., even when etching an aluminum pattern or the like, the corrosion after the processing is obtained. Can be prevented.

When the thickness of the tray is about 2 mm, the flatness is 0.02 or less, and the flatness of the lower electrode of the ashing chamber is 0.01 or less, the thermal conductivity of the wafer is improved and the wafer is placed on the tray. Ashing can be carried out even when the device is loaded.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the plasma processing apparatus of the present invention will be described below with reference to FIGS.

1 and 2, a tray cassette 1 accommodating a tray 2 is provided on one side (left side) on the atmosphere side in the lower part of FIG. 1, and an unprocessed wafer 4 is placed on the tray cassette 1. Is placed.
The tray cassette 1 on which the wafer cassette 3 containing the unprocessed wafers 4 is placed is set on a cassette lifting stage 5. A wafer cassette 3 for storing processed wafers 4 is provided on the other side (right side) in the lower part of FIG. 1, and is also set on a cassette elevating stage 5. Reference numeral 6 denotes a handling arm disposed at the center of the cassette lifting stage 5 on both sides. A combination station 7 is disposed between the handling arm 6 and the vacuum side and combines the wafer 4 on the tray 2.

On the vacuum side, the etching processing chamber 12, the rinsing chamber 13, the ashing chamber 14, the load lock chamber 15 which repeats the atmosphere and the vacuum, and the load lock chamber 15 for transferring the tray on which the wafer 4 is loaded between the two chambers. And a transfer arm 16 of a double arm type disposed therein. Note that a wafer transfer mechanism between the chambers 12 to 15 is described in Japanese Patent Application No. Hei.
As disclosed in Japanese Patent Application No. 6-256799, the wafer transfer mechanism between the load lock chamber 15 and the rinsing chamber at the back of the load lock chamber 15 can be used.

As shown in FIG. 3, the combination station 7 supports the tray 2 so as to be able to move up and down, and
A tray positioning plate 8 that can be raised and lowered and rotatable for positioning in the rotation direction, push-up pins 9 for supporting the wafer 4 and placing it on the tray 2, and a transmission type for detecting the position of the tray 2 in the rotation direction Sensor 10 and wafer 4
And a wafer centering means 11 for performing centering.

FIG. 4 shows a spin chuck 19 provided in the rinsing chamber 13. The wafer 4 and the tray 2 which have been subjected to the etching process or the ashing process are
When it is placed on the surface of the spin chuck 9, it is vacuum-sucked by a suction groove 19 a on the upper surface of the spin chuck 19 provided to be able to communicate with a vacuum source. The suction of the wafer 4 is performed simultaneously with the suction of the tray 2 through the suction hole 2a formed through the tray 2. In addition, the through hole of the push-up pin 9 can be used as the suction hole 2a. Then, the trait 2 and the wafer 4 are sucked and rotated, and a rinsing process using pure water and a chemical solution is performed.

FIG. 5 shows a processing state in the ashing chamber 14. The lower electrode 20 is provided in the ashing chamber 14, and the ashing processing is performed by placing the tray 2 on which the wafer 4 is mounted on the lower electrode 20. Is configured.

Next, the plasma processing operation of the above configuration will be described. First, the handling arm 6 on the atmosphere side faces the cassette lifting stage 5 on one side. The cassette elevating stage 5 moves up and down to a position where the height of the lowermost tray 2 in the tray cassette 1 and the handling arm 6 become the same. Next, after the cassette elevating stage 5 is raised by half a pitch and the handling arm 6 is advanced, the tray cassette 1 is lowered by a half pitch, and the tray 2 is placed on the handling arm 6 and transported to the station 7.

In the station 7, the positioning plate 8
Rises, the tray 2 is transferred onto the tray positioning plate 8, and the handling arm 6 retreats. And
By rotating the tray positioning plate 8, the transmission type sensor 1
After the positioning of the push-up pin 9 and the push-up hole 9 formed on the tray 2 is performed by using the position 0, the tray 2 is placed on the station 7 and supported. Next, the cassette lifting stage 5 is lowered to a position where the handling arm 6 and an arbitrary wafer 4 in the wafer cassette 3 are at the same height, and the wafer 4 is taken out by the handling arm 6 in the same manner as the tray 2 is taken out. Then, the wafer 4 is transferred onto the station 7. Next, the push-up pin 9 moves up,
The wafer 4 is separated from the handling arm 6, and the handling arm 6 moves backward. In this state, the wafer 4 is centered by the centering means 11 so that the wafer 4 is placed on the center of the tray 2, and then the push-up pins 9 are lowered to place the wafer 4 on the center of the tray 2.

Thereafter, the gate 17 of the load lock chamber 15 under the atmospheric pressure is opened, and the wafer 4 is carried into the load lock chamber 15 together with the tray 2 by the transfer arm 16. After the gate 17 is closed, the load lock chamber 15 is evacuated to a vacuum. After the load lock chamber 15 and the etching chamber 12 which is always in a vacuum state have the same pressure, the gate 18 is opened and the transfer arm 16 opens the etching chamber 12. Transported to Then, an etching gas is injected, high-frequency power is applied, and plasma etching is started. After the etching is completed, the load is returned to the load lock chamber 15 by the transfer arm 16 in the reverse procedure, and then the inside of the load lock chamber 15 is returned to the atmospheric pressure by nitrogen purge.

During the continuous processing, the wafer 4 can be replaced with the unprocessed wafer 4 after the etching is completed in the etching processing chamber 12 by the transfer arm 16 of the double arm system while the wafer is placed on the tray.

Then, if necessary, a rinsing chamber 13 described later is used.
After the rinsing process and the ashing process of the wafer 4 in the ashing chamber 14 are completed, the wafer 4 is transferred to the station 7.
At the station 7, the push-up pin 9 moves up,
The wafer 4 is separated from the tray 2. Then, only the wafer 4 is taken out of the station 7 by the atmosphere-side handling arm 6 and stored in the wafer cassette 3.

Thereafter, a new wafer 4 is transferred by the handling arm 6 onto the tray 2 remaining in the station 7, and the wafer 4 is processed as needed. Thus, a series of operations is completed. Thereby, the processing is performed by circulating the processing chambers 12 to 15 and the tray 2 arranged in the combination station 7.

Further, the tray cassette 1 is provided with an inch-size display section for the wafers 4 stored in the wafer cassette 3 thereon, and a sensor (not shown) for recognizing the display on the cassette lifting stage 5. By replacing the tray cassette 1 with one for a different inch size, the sensor recognizes the inch size, adjusts the pushing-up height of the wafer pushing-up pin 9 at the combination station 7, and adjusts the size to the appropriate size. The centering can be performed by using the wafer centering means 11 described above. In addition, the operation screen and the recipe settings can be automatically switched.

The rinsing processing operation after the etching or ashing processing is described. The processed wafer 4 and the tray 2 are transferred to the rinsing chamber 13 by the transfer arm 16, where the tray 4 is moved as shown in FIG. The wafer 2 and the wafer 4 are placed on a spin chuck 19 and are vacuum-adsorbed. Then, the spin chuck 19 is rotated and the tray 2 is rotated.
And the wafer 4 are rotated together to rinse pure water and chemicals. After the wafer 4 is rinsed, the tray 2 and the wafer 4
Is transferred to the load lock chamber 15 by the transfer arm 16.

In the ashing process after the etching process, the wafer 4 is placed on the tray 2 as shown in FIG.
The operation is performed by placing the tray 2 on the lower electrode 20 for ashing. At this time, the problem is how the temperature of the lower electrode 20 is transmitted to the wafer 4 via the tray 2. For example, when the thickness of the tray 2 is about 2 mm, the flatness of the tray 2 is 0.02. By setting the flatness of the upper surface of the lower electrode 20 to 0.01 or less, the temperature of the lower electrode 20 can be sufficiently transmitted to the wafer 4 placed on the tray 2, and the tray 2 can be ashed. It becomes possible.

[0029]

According to the plasma processing method of the present invention, there are provided a step of placing a wafer on a tray as described above, and a step of carrying a plasma process by transporting the wafer into the processing chamber with the wafer placed on the tray. The wafer can be prevented from cracking by carrying and processing the wafer placed on a tray.

If the wafer is placed on a tray without being exposed to the atmosphere after the plasma treatment and both are sucked and rotated and rinsed with pure water and a chemical solution, the aluminum pattern and the like can be etched even after etching. Corrosion can be prevented.

Further, according to the plasma processing apparatus of the present invention, a cassette stage in which a tray cassette is disposed below a wafer cassette, an atmosphere-side handling arm capable of transporting both a wafer and a tray, and a wafer being pushed up when a wafer is transferred A combination station having a tray position determination function for raising pins and a function of centering the wafer so that the wafer can be placed at the center of the tray is provided, so that the wafer is placed on the tray and transported and processed. The above method can be implemented to prevent the wafer from cracking.

If the processing is performed by circulating the number of processing chambers + 1 trays between each processing chamber and the combination station, the above processing can be performed at a low cost with the minimum number of trays. .

If the wafer size can be switched only by changing the tray cassette, operations such as positioning at the combination station and setting of a recipe when the wafer size is switched can be performed automatically.

Further, if a rinsing chamber for rotating both the tray and the wafer by using a spin chuck capable of adsorbing and rinsing with a pure water and a chemical solution is provided, even when etching an aluminum pattern or the like, the corrosion after the processing is provided. Can be prevented.

When the thickness of the tray is about 2 mm, the flatness is 0.02 or less, and the flatness of the lower electrode of the ashing chamber is 0.01 or less, the thermal conductivity of the wafer is improved and the wafer is placed on the tray. Ashing can be carried out even when the device is loaded.

[Brief description of the drawings]

FIG. 1 is a plan view illustrating a schematic configuration of an embodiment of a plasma processing apparatus of the present invention.

FIG. 2 is a vertical sectional view of a cassette elevating stage and a handling arm in the embodiment.

FIG. 3 is a vertical sectional view of a positioning station according to the embodiment.

4A and 4B show a state in which a tray and a wafer are sucked on a spin chuck in a rinsing chamber in the same embodiment, FIG. 4A is a plan view without the wafer, and FIG. 4B is a longitudinal sectional view.

FIG. 5 is a longitudinal sectional view of an electrode portion of the ashing chamber in the same embodiment.

FIG. 6 is a plan view showing a schematic configuration of the conventional plasma processing apparatus.

[Explanation of symbols]

 Reference Signs List 1 tray cassette 2 tray 3 wafer cassette 4 wafer 5 cassette elevating stage 6 handling arm 7 combination station 9 push-up pin 11 wafer centering means 12 etching processing chamber 13 rinse chamber 14 ashing chamber 15 load lock chamber 16 transport arm 19 spin chuck 20 lower electrode

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideo Haraguchi 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Matsuda 1006 Kazuma Kazuma Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. 72) Inventor Shoji Fukui 1006 Kazuma Kadoma, Kazuma City, Osaka Prefecture F-term in Matsushita Electric Industrial Co., Ltd.

Claims (7)

[Claims] 1. A plasma processing method comprising: a step of placing a wafer on a tray; and a step of transporting the wafer loaded on the tray into a processing chamber to perform plasma processing. 2. The plasma processing method according to claim 1, wherein, after the plasma processing, the wafer is placed on the tray without being exposed to the atmosphere, both of the wafers are sucked and rotated, and the wafer is rinsed with pure water and a chemical solution. . 3. A cassette stage in which a tray cassette is arranged below a wafer cassette; an atmosphere-side handling arm capable of transporting both wafers and trays; and a tray position determining function for raising pins for pushing up wafers during wafer transfer. A plasma processing apparatus comprising: a combination station having a function of centering a wafer so that the wafer can be placed at the center of the tray; and transporting and processing the wafer placed on the tray. 4. The plasma processing apparatus according to claim 3, wherein the number of processing chambers plus one tray is circulated between each processing chamber and the combination station to perform the processing. 5. The plasma processing apparatus according to claim 3, wherein the wafer size can be switched only by replacing the tray cassette. 6. The plasma processing apparatus according to claim 3, further comprising a rinsing chamber for rotating both the tray and the wafer by using a spin chuck capable of adsorbing the wafer and rinsing with a pure water and a chemical solution. 7. A tray having a thickness of about 2 mm and a flatness of 0.
02 or less, and the flatness of the lower electrode of the ashing chamber is set to 0.
4. The plasma processing apparatus according to claim 3, wherein the value is set to 01 or less.