JPH03227010A - Method and device for removing resist - Google Patents

Abstract

PURPOSE:To secure a high yield rate and excellent reliability of a semiconductor device by a method wherein, after the fluorocarbon plasma-treated resist has been etched to the midway on a semiconductor substrate using oxygen-containing plasma, the semiconductor substrate is cleaned with water, and then it is retreated by the plasma containing oxygen. CONSTITUTION:As a fluorocarbon plasma treatment is conducted on the semiconductor device, on which dry etching is performed on an aluminum alloy film 3 using a resist 4 as a mask, in order to prevent corrosion on the aluminum alloy film 3, fluoric polymer 5 is deposited on the whole semiconductor device. A resist-removing operation is conducted on the semiconductor device until the residual film of resist becomes about 0.2mum using oxygen plasma. Then, when the semiconductor device is cleaned, the fluoric polymer 5, which was deposited on the side wall of the already removed resist 4, is mechanically removed. The surface of the aluminum alloy film 3 becomes clean having no residual substance by conducting resist-removing operation as far as to the endpoint and then a cleaning with water is performed thereon.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a resist removal method and a resist removal apparatus used in the manufacturing process of semiconductor devices.

BACKGROUND OF THE INVENTION Conventionally, a method for removing resist after dry etching has consisted of a resist removal step using oxygen-containing plasma, followed by a water washing step.

A conventional resist removal method will be described below. FIG. 7 (al~(C1 is a process cross-sectional view of a semiconductor device showing a flowchart of a conventional resist removal method, in which 1 is a semiconductor substrate made of silicon, 2 is a silicon oxide film, 3
4 is a positive photoresist; 5 is a fluorine-based polymer formed after etching the aluminum alloy film 3; and 6 is a resist-degraded film.

First, as shown in FIG. 7 (al), the semiconductor device after dry etching the aluminum alloy film 3 using the resist 4 as a mask has been subjected to fluorocarbon plasma treatment to prevent corrosion of the aluminum alloy film 3. A fluorine-based polymer 5 is deposited on the entire semiconductor device. When the resist is removed from this semiconductor device using a resist removal device using oxygen-containing plasma, as shown in FIG.
The resist 4 is removed, but the fluorine-based polymer 5 deposited on the side walls of the resist 4 collapses during the removal of the resist 4. As a result, the resist is not removed from the portion covered by the fallen fluorine-based polymer 5, and a resist deterioration film 6 is formed. Next, when this semiconductor device is washed with water, the fallen fluorine-based polymer 5 is mechanically removed, but the resist deterioration film 6 remains without being removed.

Problems to be Solved by the Invention However, in the conventional resist removal method described above, the altered resist film 6 is not removed and remains, so the altered resist film 6 is peeled off during post-processing or after completion, resulting in a decrease in yield and an increase in the quality of semiconductor devices. The problem was that it caused reliability problems. The present invention solves the above conventional problems,
An object of the present invention is to realize a resist removal method that provides a high yield and excellent reliability of semiconductor devices by also removing a resist degraded film when removing the resist in the manufacturing process of a semiconductor device.

Another object of the present invention is to realize a resist removal apparatus that performs a resist removal method simply and efficiently.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention includes a first step of etching a resist that has been subjected to fluorocarbon plasma treatment on a semiconductor substrate halfway with oxygen-containing plasma, and etching the semiconductor substrate. The method includes a second step of washing with water, and a third step of reprocessing the semiconductor substrate with plasma containing oxygen.

According to the structure of the present invention, the resist removal process is temporarily stopped at an intermediate stage, so that it is possible to prevent the fluorine-based polymer deposited on the side walls of the resist from falling down during the resist removal. Therefore, since the formation of a resist-altered film can be prevented, a resist removal method with high yield of semiconductor devices and excellent reliability can be realized.

In carrying out the resist removal method of the present invention, it is not necessary to move the semiconductor device back and forth between the resist removal device and the water washing device for a total of one and a half trips, so it is possible to realize a simple and efficient resist removal device. .

The present invention also makes it possible to achieve high yield and excellent reliability of semiconductor devices by sputter-etching the altered resist film using plasma.

EXAMPLE Hereinafter, a first example of the resist removal method of the present invention will be described with reference to the drawings. Figure 1 (al~+
el is a process cross-sectional view of a semiconductor device showing a flowchart of a resist removal method in an embodiment of the present invention.

1 is a silicon substrate, 2 is a silicon oxide film, 3 is an aluminum alloy film, 4 is a positive photoresist, and 5 is a fluorine-based polymer.

First, as shown in FIG. Fluorine-based polymer 5 is deposited throughout the device. Using oxygen plasma, this semiconductor device is subjected to resist removal until the remaining resist film is about 0.2 μm, as shown in FIG. 1 tb+. Next, when this semiconductor device is washed with water,
As shown in Fig. 1 (Cj), the fluorine-based polymer 5 deposited on the side wall of the resist 4 that has already been removed is mechanically removed.
If the resist is removed to the final point as shown in FIG. 1, and then washed with water, the surface of the aluminum alloy film 3 will be clean without any residue, as shown in FIG.

As described above, according to this embodiment, the first resist removal step using oxygen-containing plasma and the subsequent first removal step are performed using oxygen-containing plasma.
The fluorine-based polymer 5 deposited on the side walls of the resist 4 is removed by providing a water washing step, a subsequent resist removal step using oxygen-containing plasma, and a subsequent water washing step. Since the resist 4 does not fall during removal, no resist deterioration film is formed, so that high yield and reliability of the semiconductor device can be obtained.

Note that if the remaining resist film is 0.1 μm or less at the end of the first resist removal process, there is a risk that the fluorine-based polymer 5 will fall down during the first resist removal process and a resist deteriorated film will be formed. There is.

Furthermore, if the remaining resist film is 0.5 μm or more at the end of the first resist removal process, there is a risk that the fluorine-based polymer 5 will fall down during the second resist removal process and a resist deteriorated film will be formed. be.

Next, a first embodiment of the resist removing apparatus of the present invention will be described with reference to the drawings. FIG. 2 is a sectional view of a resist removing apparatus in an embodiment of the present invention. 7
is a wafer cassette before processing, 8 is a transfer arm, 9 is a silicon substrate, 10 is a substrate holder made of stainless steel, 11 is a reaction chamber wall made of quartz, 12 is a magnetron oscillator, 13 is a waveguide, and 14 is a 02 is an inlet, 15 is an exhaust port, 16 is a rotatable substrate holder having a mechanism for vacuum chucking the silicon substrate 9, 17 is a rotating shaft that transmits rotation to the substrate holder 16, 18 is a shield that prevents washing water from scattering, 19 20 is a cleaning water nozzle, 20 is a wafer cassette after processing, 21 is a first resist removal device using oxygen-containing plasma, 22 is a first water washing device, and 23 is a second resist removal device using oxygen-containing plasma. Resist removal device, 24
is the second water washing device.

The operation of the resist removing apparatus of this embodiment configured as described above will be explained.

First, the silicon substrate 9 housed in the wafer cassette 7 before processing is transferred to the first resist removal device 21 by the transfer arm 8, and oxygen plasma is used to remove the resist at a point when the remaining resist film is approximately 0.2 μm. Perform resist removal until

Next, the silicon substrate 9 is transported by the transport arm 8 to the first water washing device 22, and washed with water to mechanically remove the polymer deposited on the side walls of the resist. Furthermore, the silicon substrate 9 is transported by the transport arm 8 to the second resist removing device 23, and the resist is removed to the end point.

Finally, the silicon substrate 9 is transported by the transport arm 8 to the second water washing device 24 and is washed with water.

According to this embodiment, the first resist removing device 21, the first water washing device 22, the second resist removing device 23,
A second water washing device 24 , a transfer arm 8 that automatically transports the silicon substrate 9 from the first resist removing device 21 to the first water washing device 22 , and a transfer arm 8 that automatically transports the silicon substrate 9 from the first water washing device 22 to the first water washing device 24 .
The transfer arm 8 that automatically transfers the silicon substrate 9 from the resist remover 2 to the second resist removing device 23 and the transfer arm 8 that automatically transfers the silicon substrate 9 from the second resist removing device 23 to the second water washing device 24 are combined into one device. By providing this, it is not necessary to make one and a half trips between the resist removing device and the water washing device, so that the resist can be removed easily and efficiently.

A second embodiment of the resist removal method of the present invention will be described below with reference to the drawings. 3rd [Hal～(
dl is a process cross-sectional view of a semiconductor device showing a flowchart of a resist removal method in an embodiment of the present invention.

1 is a silicon substrate, 2 is a silicon oxide film, 3 is an aluminum alloy film, 4 is a positive photoresist, and 5 is a fluorine-based polymer 6 is a resist-degraded film, which are the same as in the conventional example.

The resist removal method of this embodiment will be explained.

First, as shown in FIG. 3, the semiconductor device after the dry etching of the aluminum alloy film 3 is subjected to fluorocarbon plasma treatment to prevent corrosion of the aluminum alloy film 3, so the entire semiconductor device is coated with fluorine-based polymer. 5 is deposited. When this semiconductor device is subjected to resist removal using a resist removal device using oxygen-containing plasma, the resist 4 is removed as shown in FIG.
The fluorine-based polymer 5 deposited on the side wall of the resist 4 collapses while the resist 4 is being removed. Therefore, the resist cannot be removed from the part covered with the fallen fluorine-based polymer 5.
A resist altered film 6 is formed. Next, when this semiconductor device is washed with water, the fallen fluorine-based polymer is mechanically removed, but as shown in FIG. 3 (C1), the resist deterioration film 6 remains without being removed.

Then, this semiconductor device is further placed in a sputter etching apparatus using oxygen-containing plasma and the altered resist film 6 is sputter etched, whereby the altered resist film 6 is removed as shown in FIG. 3f). Finally, the resist removal process is completed by washing the semiconductor device with water again.

According to this embodiment, by providing a sputter etching step after the first water washing step, the resist deteriorated film 6 can be removed, so that a high yield and excellent reliability of the semiconductor device can be obtained.

Regarding the second embodiment of the resist removal device of the present invention,
This will be explained with reference to the drawings. FIG. 4 is a sectional view of a resist removing apparatus in an embodiment of the present invention. 25 is a lower electrode, 26 is a professional soaking capacitor, 27 is a high frequency power source with a frequency of 13.56 MHz (7), 28 is a reaction chamber wall at ground potential, and 29 is a sputter etching device using oxygen-containing plasma. . Note that 7 is the Univaccent before processing, 8 is the transfer arm, 9 is the silicon substrate, 10 is the substrate holder, 11 is the reaction chamber wall, 2 is the magnetron oscillator, 13 is the waveguide, 14 is the inlet of 02, and 15 is the exhaust port. , 16 is a substrate holder, 17 is a rotating shaft, 18 is a shield, 19 is a nozzle, 20 is a wafer cassette after processing, 21
2 is a resist removing device, 22 is a first water washing device, and 24 is a second water washing device, which are the same as in the embodiment of the resist removing device of the present invention shown in FIG.

The operation of the resist removing apparatus of this embodiment configured as described above will be explained.

First, the silicon substrate 9 stored in the wafer cassette 7 before processing is transferred to the resist removal device 2 by the transfer arm 8.
1, and the resist is removed to the end point using oxygen plasma. Next, the silicon substrate 9 is transported by the transport arm 8 to the first water washing device 22, and washed with water to mechanically remove the polymer deposited on the side walls of the resist. Further, the silicon substrate 9 is transferred to a sputter etching device 29 by the transfer arm 8, and the deteriorated resist film is removed by a drying process. Finally, the silicon substrate 9 is transported by the transport arm 8 to the second water washing device 24 and is washed with water.

According to the present embodiment, the resist removing device 21, the first water washing device 22, the Svatutae Sochi device 29, the second water washing device 24, and the resist removing device 21 remove the silicon substrate 9.
The transport arm 8 automatically transports from the to the first water washing device 22
, a transfer arm 8 that automatically transfers the silicon substrate 9 from the first water washing device 22 to the sputter etching device 29, and a transfer arm 8 that automatically transfers the silicon substrate 9 from the sputter etching device 29 to the second water washing device 24. By providing these in one device, when removing the resist, the silicon substrate 9 is transferred from the resist removal device 21 to the first water washing device 22, and then from the first water washing device 22 to the sputter etching device 29. Furthermore, since there is no need to carry the resist from the sputter etching device 29 to the second water washing device 24, the resist can be removed easily and efficiently.

Regarding the third embodiment of the resist removal method of the present invention,
This will be explained with reference to the drawings. FIG. 5 (al to (di) are process cross-sectional views of a semiconductor device showing a flowchart of a resist removal method in an embodiment of the present invention. 1 is a silicon substrate, 2 is a silicon oxide film, 3 is an aluminum alloy film, 4 is a positive photoresist, 5 is a fluorine-based polymer, and 6 is a resist-altered film, which are the same as in the conventional example.

The resist removal method of this embodiment will be explained.

As shown in Figure 5 (al), the semiconductor device after the dry etching of the aluminum alloy film 3 is subjected to fluorocarbon plasma treatment to prevent corrosion of the aluminum alloy film 3. A polymer 5 is deposited on the semiconductor device. When the resist is removed from this semiconductor device using a resist removal device using oxygen-containing plasma, the resist 4 is removed as shown in FIG.
The fluorine-based polymer 5 deposited on the side wall of the resist 4 collapses while the resist 4 is being removed. Therefore, the resist cannot be removed from the part covered with the fallen fluorine-based polymer 5.
A resist altered film 6 is formed. Next, when this semiconductor device is washed with water, the fallen fluorine-based polymer is mechanically removed, but the deteriorated resist film 6 remains without being removed, as shown in FIG. 5(C).

Therefore, this semiconductor device is further placed in a fuming nitric acid cleaning equipment, and the deteriorated resist film 6 is etched with sea urchin for 30 seconds, so that the deteriorated resist film 6 is removed as shown in FIG. By washing with water again, the process of removing the resist from the fuming nitric acid remaining on the surface of the semiconductor device is completed.

According to this embodiment, by providing a fuming nitric acid cleaning step after the first water washing step, the resist deterioration film 6 can be removed, so that a high yield and excellent reliability of the semiconductor device can be obtained. .

Note that if the time for cleaning with fuming nitric acid is less than 10 seconds, there is a possibility that the resist deterioration film 6 may not be completely removed. Furthermore, if the time for cleaning with fuming nitric acid exceeds 300 seconds, there is a possibility that the aluminum alloy film 3 will be corroded by the fuming nitric acid.

Regarding the third embodiment of the resist removal device of the present invention,
This will be explained with reference to the drawings. FIG. 6 is a sectional view of a resist removing apparatus in an embodiment of the present invention. 30 is a fuming nitric acid cleaning device.

Note that 7 is a wafer cassette before processing, 8 is a transfer arm, and 9 is a wafer cassette before processing.
is a silicon substrate, 10 is a substrate holder, 11 is a reaction chamber wall, 12 is a magnetron oscillator, 13 is a waveguide, and 14 is 0
2 inlet, 15 exhaust port, 16 substrate holder 17
2 is a rotating shaft, 18 is a shield, 19 is a nozzle, 20 is a wafer cassette after processing, 21 is a resist removing device, 22 is a first water washing device, and 24 is a second water washing device, which are shown in FIG. This is similar to the case of an embodiment of the resist removing apparatus according to claim 3 of the present invention.

The operation of the resist removing apparatus of this embodiment configured as described above will be explained.

First, the silicon substrate 9 stored in the wafer cassette 7 before processing is transferred to the resist removal device 21 by a transfer arm.
The resist is removed to the final point using oxygen plasma. Next, the silicon substrate 9 is transferred to the first
The polymer deposited on the side walls of the resist is mechanically removed by washing with water.

Further, the silicon substrate 9 is transported by the transport arm 8 to the fuming nitric acid cleaning device 30, and wet etched for 30 seconds using fuming nitric acid to remove the altered resist film.

After that, increase the rotation speed of the substrate holder and remove the silicon substrate 9.
After removing the fuming nitric acid remaining on the surface of the silicon substrate 9, pure water is jetted from the nozzle 19 to clean the silicon substrate 9. Finally, the silicon substrate 9 is transported by the transport arm to the second washing device 24, and is washed again. By providing the second water washing device 24 after the fuming nitric acid cleaning device 30 in this manner, corrosion of the aluminum alloy film due to residual fuming nitric acid can be prevented.

According to this embodiment, the resist removing device 21, the first water washing device 22, the fuming nitric acid washing device 30, the second water washing device 24, and the silicon substrate 9 are removed from the cyst removing device 21 through the first water washing. a transfer arm 8 that automatically transfers to the device 22;
A transport arm 8 that automatically transports the silicon substrate 9 from the first water washing device 22 to the fuming nitric acid cleaning device 30; and a transport arm 8 that automatically transports the silicon substrate 9 from the fuming nitric acid cleaning device 30 to the second water washing device 24. By providing these in one device, when removing the resist, the silicon substrate 9 is transferred from the resist removing device 21 to the first water washing device 2.
2, since there is no need to carry the resist from the first water washing device 22 to the fuming nitric acid washing device 30 and further from the fuming nitric acid washing device 30 to the second water washing device 24, the resist can be easily and efficiently removed. can be done.

Effects of the Invention According to the resist removal method of the present invention, there is a first resist removal step using oxygen-containing plasma, a subsequent first water washing step, and a subsequent resist removal step using oxygen-containing plasma. By providing the second removal process and the second water washing process that follows, it is possible to prevent the fluorine-based polymer deposited on the sidewalls of the resist from falling down during the removal of the resist. Since formation can be prevented, it is possible to realize a resist removal method that provides high yield and excellent reliability of semiconductor devices.

Further, according to the removing apparatus of the present invention, the first resist removing apparatus using oxygen-containing plasma, the first water washing apparatus, the second resist removing apparatus using oxygen-containing plasma, and the second resist removing apparatus using oxygen-containing plasma are provided. a water washing device; a first transport device that automatically transports the semiconductor substrate from the first resist removal device to the first water washing device; and a first transport device that automatically transports the semiconductor substrate from the first water washing device to the second resist removal device. By providing a second transport device that transports the semiconductor substrate and a third transport device that automatically transports the semiconductor substrate from the second resist removal device to the second water washing device, when removing the resist, the resist removal device Since the semiconductor device does not need to be moved back and forth between the washing device and the water washing device for a total of one and a half trips, it is possible to realize a resist removal device that performs a resist removal method simply and efficiently.

The resist removal method of the present invention includes a resist removal step using oxygen-containing plasma, a subsequent first water washing step, a subsequent sputter etching step of a resist-altered film using plasma, and a subsequent second step. By providing a water washing step, the altered resist film can be sputter-etched and the altered resist film can be removed, thereby realizing a resist removal method that provides high yield and excellent reliability of semiconductor devices. It is.

The resist removal apparatus of the present invention includes a resist removal apparatus using oxygen-containing plasma, a first water washing apparatus, a sputter etching apparatus for resist-altered film using plasma, a second water washing apparatus, and a semiconductor substrate. a first transport device that automatically transports the semiconductor substrate from the resist removing device to the first water washing device; a second transport device that automatically transports the semiconductor substrate from the first water washing device to the sputter etching device; By providing a third conveying device that automatically conveys the resist from the etch device to the second water washing device, when carrying out the resist removal method described in claim 4, the resist removing device can transfer the resist from the resist removing device to the water washing device, and then to the water washing device. to sputtering equipment,
Furthermore, since there is no need to carry the semiconductor device from the sputtering device to the water washing device, it is possible to realize a resist removal device that performs a resist removal method simply and efficiently.

The resist removal method of the present invention includes a resist removal step using oxygen-containing plasma, followed by a first water washing step, a subsequent washing step using acid, and a subsequent water washing step. As a result, since the altered resist film can be sputter-etched, the altered resist film can be removed, thereby realizing a resist removal method that provides high yield and excellent reliability of semiconductor devices.

The resist removal apparatus of the present invention includes a resist removal apparatus using plasma containing oxygen, a first water washing apparatus, a washing apparatus using acid, a second water washing apparatus, and a semiconductor substrate removed from the resist removal apparatus. The first one that is automatically transported to the first water washing device.
a second transport device that automatically transports the semiconductor substrate from the first water washing device to the acid cleaning device; and a second transport device that automatically transports the semiconductor substrate from the acid cleaning device to the second water washing device. By providing the third conveyance device, when carrying out the resist removal method according to claim 6, the resist removal device is transferred to the water washing device, then from the water washing device to the washing device using acid, and then from the water washing device to the washing device using acid. Since there is no need to carry the semiconductor device from the cleaning device using the water washing device to the water washing device, it is possible to realize a resist removal device that performs the resist removal method described in claim 6 simply and efficiently.

[Brief explanation of drawings]

1 (al to tel are step-by-step sectional views of a semiconductor device showing a flowchart of a resist removal method in an embodiment of the present invention; FIG. 2 is a sectional view of a resist removal apparatus in an embodiment of the present invention; 3 (al to (di) are step-by-step cross-sectional views of a semiconductor device showing a flowchart of a resist removal method in another embodiment of the present invention; FIG. 4 is a cross-sectional view of a resist removal apparatus in another embodiment of the present invention. Cross-sectional views, FIGS. 5A to 5D are step-by-step cross-sectional views of a semiconductor device showing a flowchart of a resist removal method in another embodiment of the present invention, and FIG. 6 is a flowchart of a resist removal method in another embodiment of the present invention. The cross-sectional views of the device and FIGS. 7 (al to fc) are step-by-step cross-sectional views of the semiconductor device showing a flowchart of a conventional resist removal method. 1...Silicon substrate, 2...・Silicon oxide film, 3... Aluminum alloy film, 4...
...Positive photoresist, 5...Fluorine-based polymer 6...Resist altered film, 7...
... Ueno 1 cassette before processing, 8 ... Transfer arm, 9 ... Silicon substrate, 10 ...
・Substrate holder 11...Reaction chamber wall, 12...
...Magnetron oscillator, 13 ... Waveguide, 14 ... 0° inlet, 15 ... Exhaust port, 16 ... Rotatable board holder 17
......A rotating shaft that transmits rotation to the substrate holder 16,
18...nold, 19...nozzle,
20...Wafer cassette after processing, 21...
...first resist removal device, 22...first
water washing device, 23... second resist removal device, 24... second water washing device, 25...
Lower electrode, 26...Blocking capacitor,
27... High frequency power supply, 28... Reaction chamber wall, 29... Sputter etching device, 30...
...Fuming nitric acid cleaning equipment.

Claims (5)

[Claims] (1) A first step of forming a resist treated with fluorocarbon plasma on a semiconductor substrate, and then etching the resist using oxygen-containing plasma so that at least a portion of the resist remains; and cleaning the semiconductor substrate with water. and a third step of treating the semiconductor substrate with plasma containing oxygen. (2) The resist removal method according to claim 1, wherein the plasma treatment containing oxygen is sputter etching. (3) A first step of forming a resist treated with fluorocarbon plasma on a semiconductor substrate, and then etching the resist using oxygen-containing plasma so that at least a portion of the resist remains; and cleaning the semiconductor substrate with water. and a third step of treating the semiconductor substrate with fuming nitric acid for 10 to 300 seconds. (4) The semiconductor device is passed through a first oxygen plasma processing device for processing a semiconductor substrate, a first water washing device, a second oxygen plasma processing device, and a second water washing device in this order. Resist removal equipment arranged side by side for processing. (5) a first oxygen plasma processing device for processing a semiconductor substrate, a first water washing device, and a fuming nitric acid processing device;
A resist removing device including a second water washing device and a second water washing device arranged side by side so as to pass through the semiconductor device in this order.