This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2012-017262, filed on Jan. 30, 2012; the entire contents of which are incorporated herein by reference.
Embodiments described herein relate generally to a method and an apparatus for manufacturing a semiconductor device.
The manufacturing processes of a semiconductor device include various processes such as lithography processes, etching processes, ion implantation processes, etc. After ending each process, and prior to transferring to the next process, a wet cleaning process and a drying process are implemented to clean the front surface of the substrate by removing impurities and/or residue remaining on the front surface of the substrate.
With the downscaling of elements formed in substrates in recent years, a problem occurs where fine resist patterns and device patterns that are formed by lithography processes and etching processes collapse in the wet cleaning process and the drying process.
In general, according to one embodiment, a method is disclosed for manufacturing a semiconductor device. The method can rinse a substrate with water, a plurality of protruding patterns being formed on the substrate. The method can dry the substrate by removing water from a recess between the protruding patterns by irradiating microwaves.
According to another embodiment, an apparatus for manufacturing a semiconductor device includes a chemical liquid supply unit, a water supply unit and a drying mechanism. The chemical liquid supply unit is configured to supply a chemical liquid to a processing body to clean the processing body. The water supply unit is configured to supply water to the processing body to rinse the processing body. The drying mechanism is configured to remove water from a front surface of the processing body. The drying mechanism includes a microwave irradiation unit configured to irradiate microwaves onto the processing body.
Various embodiments will be described hereinafter with reference to the accompanying drawings.
First, a first embodiment will be described.
First, the process in which the protruding patterns are formed in the method for manufacturing the semiconductor device according to this embodiment will be described.
As illustrated in
Then, as illustrated in step S102, for example, a silicon oxide film is formed with a film thickness of 5 nm as a gate insulating film 12 on the semiconductor substrate 11.
Continuing as illustrated in step S103, for example, a polysilicon film is formed with a film thickness of 100 nm as a conductive film 13 used to form a gate electrode on the gate insulating film 12. For example, the conductive film 13 is a film used to form a FG (floating gate) electrode of NAND flash memory.
Then, as illustrated in step S104, for example, a silicon nitride film used to form an etching stopper film 14 is formed with a film thickness of 100 nm on the conductive film 13.
Continuing as illustrated in step S105, for example, a silicon oxide film is formed with a film thickness of 250 nm as a mask film 15 used to form a hard mask on the etching stopper film 14
Then, as illustrated in step S106, for example, a sacrificial film 16 is formed with a film thickness of 100 nm on the mask film 15. The sacrificial film 16 is a film made of a material having RIE (reactive ion etching) selectivity with the mask film 15 formed under the sacrificial film 16.
Continuing as illustrated in step S107, a resist film 17 is formed on the sacrificial film 16. The resist film 17 is formed to include multiple patterns 18 having line configurations extending in one direction in a plane parallel to the upper surface of the sacrificial film 16 by using lithography. The spaces between the patterns 18 are called pattern space portions 19. The width of the pattern 18 and the width of the pattern space portion 19 are 20 nm.
Then, as illustrated in step S108, the sacrificial film 16 is patterned by RIE using the resist film 17 in which the patterns 18 are formed as a mask.
Subsequently, as illustrated in step S109, the resist film 17 is removed using SPM (Sulphuric acid Hydrogen Peroxide Mixture) which is a mixed liquid of sulfuric acid and aqueous hydrogen peroxide.
Then, as illustrated in
Thus, the protruding patterns 20 are formed on the semiconductor substrate 11. Recesses 20c are between the protruding patterns 20. A semiconductor member 21 is formed of the members formed up to this process, i.e., the semiconductor substrate 11, the gate insulating film 12, the conductive film 13, the etching stopper film 14, and the protruding patterns 20. The semiconductor member 21 includes the semiconductor substrate 11, and the hard mask 15a and the sacrificial film 16 provided on the semiconductor substrate 11. Because dirt such as etching residue, etc., is adhered to the semiconductor member 21, it is necessary to perform cleaning and drying prior to proceeding to the next process.
The methods for cleaning and drying the semiconductor member 21 will now be described.
As illustrated in step S201 of
Subsequently, as illustrated in step S202, rinsing is performed using purified water, e.g., DIW (deionized water) to remove the chemical liquid adhered to the semiconductor member 21. The rinsing is performed by replacing the chemical liquid adhered to the semiconductor member 21 with the purified water.
Then, as illustrated in step S203, the purified water used in the rinsing is removed.
The method for removing the purified water will now be described. The example illustrated in
As illustrated in
When the water 22 in the recesses 20c between the protruding patterns 20 evaporates, the water surface of the water in the recesses 20c between the protruding patterns 20 gradually decreases. Due to different heights of the water surface of the water 22 remaining in the recesses 20c, the balance of the forces caused by the capillary forces on the protruding patterns 20 degrades. Thereby, the protruding patterns 20 collapse as illustrated in
Therefore, as illustrated in
When irradiating the microwaves 23 onto the semiconductor member 21 as illustrated in
Thus, as illustrated in
Effects of this embodiment will now be described.
In the method for manufacturing the semiconductor device according to this embodiment, the microwaves 23 are irradiated onto the semiconductor member 21 after the rinsing with the purified water. Thereby, the water 22 in the recesses 20c between the protruding patterns 20 is discharged from the recesses 20c and moves onto the upper surface 20a of the protruding patterns 20. As a result, the water 22 can be removed without the protruding patterns 20 collapsing. Therefore, even in the case where a hard mask 15a that is fine is formed, the semiconductor device can be downscaled because the collapse of the hard mask 15a can be suppressed.
Although at least a portion of the protruding patterns 20 is formed in the hard mask 15a in this embodiment, this is not limited thereto. If the protruding patterns 20 are patterns having high aspect ratios, the protruding patterns 20 may be patterns formed in the resist film 17 and/or the semiconductor substrate 11.
The purified water rinse process is not limited to being performed after the cleaning process. The purified water rinse process is applicable also when performed after the developing of the lithography process.
A comparative example will now be described.
In this comparative example, the water is removed by drying by N2 blow without irradiating the microwaves. Other than the method for removing the water being drying by N2 blow, the method for manufacturing the semiconductor device is similar to that of the first embodiment described above.
In the method for manufacturing the semiconductor device according to this comparative example, the semiconductor member 21 is dried by drying by N2 blow. In the case of drying by N2 blow or natural drying, the water 22 in the recesses 20c between the protruding patterns 20 does not easily move onto the upper surface 20a of the protruding patterns 20. When the water 22 in the recesses 20c between the protruding patterns 20 evaporates, the amount of the water 22 in the recesses 20c is different between the protruding patterns 20; and the balance of the forces caused by the capillary forces on the protruding patterns 20 degrades. Thereby, there are cases where the protruding patterns 20 collapse. Therefore, it is difficult to downscale the semiconductor device.
A second embodiment will now be described.
This embodiment is an embodiment in which water-repellent processing of the front surface of the semiconductor member 21 is performed after the process of cleaning and prior to the process of rinsing with the purified water.
The content of step S301 and S302 illustrated in
As illustrated in step S303 of
Subsequently, as illustrated in step S304, water-repellent processing of the front surface of the semiconductor member 21 is performed. For example, the water-repellent processing is performed by forming a water-repellent protective film 25 using a chemical liquid (a second chemical liquid) including a silane coupling agent. In other words, the water-repellent protective film 25 is formed on the front surface of the protruding patterns 20 by causing the silane coupling agent to contact the front surface of the semiconductor member 21. The water-repellent protective film 25 may be formed using a surfactant.
Then, as illustrated in step S305, alcohol rinsing is performed to replace the chemical liquid including the silane coupling agent with alcohol.
Subsequently, as illustrated in step S306, purified water rinsing is performed to replace the alcohol rinse liquid with purified water. By performing step S305 and step S306, the chemical liquid including the silane coupling agent is replaced with the purified water.
The rinsing illustrated in step S306 may be performed using a solution in which alcohol is mixed with purified water or using acidic water in which carbon dioxide or the like is dissolved into purified water. In the case where the silane coupling agent which is directly and easily substituted for water is used in the water-repellent processing illustrated in step S304, the alcohol rinsing illustrated in step S303 and step S305 is omissible.
As illustrated in
Then, as illustrated in
Thus, the water 22 adhered to the semiconductor member 21 is removed.
Subsequently, the water-repellent protective film 25 is removed as illustrated in step S308 of
Effects of this embodiment will now be described.
Because the water-repellent protective film 25 is formed on the upper surface 20a and side surfaces 20b of the protruding patterns 20 in the semiconductor device according to this embodiment, the water remaining in the recesses 20c between the protruding patterns 20 moves easily onto the upper surface 20a when the microwaves are irradiated. The water 22 that moves onto the upper surface 20a easily drops off the semiconductor member 21. Therefore, because the water 22 no longer remains easily in the recesses 20c between the protruding patterns 20, the protruding patterns 20 collapse even less easily. Accordingly, the semiconductor device can be downscaled because the hard mask 15a does not collapse easily even in the case where a hard mask 15a that is fine is formed. Otherwise, the effects of this embodiment are similar to those of the first embodiment described above.
Similar effects can be obtained even without the water-repellent processing if the material of the protruding patterns 20 is highly water-repellent.
A test example will now be described.
As illustrated in
In the case where the protruding patterns 20 are not collapsed as illustrated in
The semiconductor device 101 according to the comparative example of the first embodiment as illustrated in
On the other hand, in the semiconductor device 1 according to the first embodiment as illustrated in
In the semiconductor device 2 according to the second embodiment as illustrated in
Comparing the methods for manufacturing the semiconductor devices of this test example as illustrated in
A third embodiment will now be described.
This embodiment is an apparatus for manufacturing a semiconductor device.
In the manufacturing apparatus 3 according to this embodiment as illustrated in
A rotation unit 32 is provided below the base unit 31. The axial unit 31b of the base unit 31 is connected to the rotation unit 32.
A nozzle unit 33 is provided above the base unit 31. The nozzle unit 33 is connected to a pipe 33a of a chemical liquid and a pipe 33b of water. The pipe 33a of the chemical liquid is called the chemical liquid supply unit; and the pipe 33b of the water is called the water supply unit.
A microwave irradiation unit 34 is provided as a portion of the drying mechanism above the base unit 31. A housing, e.g., a chamber 35 made of a metal, is provided to cover the microwave irradiation unit 34, the nozzle unit 33, and the base unit 31. A gate valve 36 is provided in the chamber 35. The gate valve 36 can be open and closed.
An operation of this embodiment, i.e., a method for using the manufacturing apparatus 3 described above, will now be described.
The gate valve 36 of the manufacturing apparatus 3 is opened; and one semiconductor member 21 having a disc configuration which is the processing body is inserted into the interior of the chamber 35 and mounted on the upper surface of the disc unit 31a of the base unit 31. A member having a front surface in which the multiple protruding patterns 20 are formed is used as the semiconductor member 21. Subsequently, the disc unit 31a and the semiconductor member 21 disposed on the disc unit 31a are rotated in the horizontal direction with the central axis of the disc unit 31a as the rotational axis by the axial unit 31b being rotated by the rotation unit 32.
Then, as illustrated in step S201 of
Continuing as illustrated in step S202 of
At this stage as illustrated in
Subsequently, as illustrated in step S203 of
Thereby, as illustrated in
Thus, as illustrated in
Effects of this embodiment will now be described.
Because the microwave irradiation unit 34 is provided in the apparatus 3 for manufacturing the semiconductor device according to this embodiment, the water 22 in the recesses 20c between the protruding patterns 20 can be discharged from the recesses 20c and moved onto the upper surface 20a of the protruding patterns 20 while suppressing the collapse of the protruding patterns 20. Therefore, the water 22 can be removed while suppressing the collapse of the protruding patterns 20 even in the case where the fine protruding patterns 20 are formed. Thereby, the semiconductor device can be downscaled.
Because the microwave irradiation unit 34 is covered with the chamber 35 that is made of a metal in the manufacturing apparatus 3 according to this embodiment, the microwaves 23 are reflected inside the chamber 35. Thereby, the microwaves 23 can be irradiated efficiently onto the semiconductor member 21.
Because the rotation unit 32 is provided in the manufacturing apparatus 3 according to this embodiment, the water 22 on the upper surface 21a can be removed from the end portion of the semiconductor member 21 by the centrifugal force.
Also, the nozzle unit 33 is provided in the manufacturing apparatus 3. Therefore, the water 22 can be squirted toward the center of the semiconductor member 21. The water 22 can be supplied uniformly to the semiconductor member 21 by being supplied while rotating the rotation unit 32.
The rotation unit 32 may be disposed either inside or outside the chamber 35.
The water-repellent processing of the second embodiment described above may be performed in the manufacturing apparatus 3 of this embodiment. In such a case, as illustrated in step S303 to step S306 of
A fourth embodiment will now be described.
As illustrated in
An operation of this embodiment, i.e., a method for using the manufacturing apparatus 4 described above, will now be described.
First, the transfer unit 37 and the water tank unit 41 are filled with the water 22. Then, one semiconductor member 21 is inserted into the interior of the chamber 35a and mounted on the upper surface of the disc unit 31a of the base unit 31. Subsequently, the disc unit 31a and the semiconductor member 21 disposed on the disc unit 31a are rotated in the horizontal direction with the central axis of the disc unit 31a as the rotational axis by the axial unit 31b being rotated by the rotation unit 32.
Then, as illustrated in step S201 of
Continuing as illustrated in step S202 of
Subsequently, the semiconductor member 21 is sealed in the interior of the transfer unit 37 that is filled with the water 22. The water adheres to the front surface of the semiconductor member 21 sealed in the transfer unit 37. Also, the water exists in the recesses 20c between the protruding patterns 20 of the semiconductor member 21. Then, the semiconductor member 21 is transferred to the interior of the chamber 35b by the transfer unit 37. Continuing, the semiconductor member 21 is mounted on the upper surface of the plate-like unit 42 in the water tank unit 41 while being immersed in the water 22.
Subsequently, the drainage hole 43 of the water tank unit 41 is opened to discharge the water 22 in which the semiconductor member 21 is sealed.
At this stage as illustrated in
Then, as illustrated in step S203 of
Thereby, as illustrated in
Thus, as illustrated in
Effects of this embodiment will now be described.
In this embodiment, the rotation unit 32 and the microwave irradiation unit 34 are separately disposed in chambers 35a and 35b. Therefore, the chemical liquid scattering from the disc unit 31a due to the rotation of the rotation unit 32 does not fall on the microwave irradiation unit 34. Therefore, corrosion of the microwave irradiation unit 34 can be prevented.
In this embodiment, the transfer unit 37 that is filled with the water 22 is disposed between the base unit 31 and the microwave irradiation unit 34. Therefore, the semiconductor member 21 can be transferred from the chamber 35a to the chamber 35b while being wet even though the base unit 31 and the microwave irradiation unit 34 are separately disposed in the chambers 35a and 35b. Therefore, the protruding patterns 20 do not collapse due to natural drying of the water 22 remaining in the recesses 20c between the protruding patterns 20 partway through the transferring of the semiconductor member 21.
Otherwise, the effects of this embodiment are similar to those of the third embodiment described above.
The plate-like unit 42 may have a disc configuration; and the plate-like unit 42 and the semiconductor member 21 on the plate-like unit 42 may be rotated with the central axis of the plate-like unit 42 as the rotational axis when irradiating the microwaves 23.
The water-repellent processing of the second embodiment described above may be performed in the manufacturing apparatus 4 of this embodiment. In such a case, the purified water and the alcohol for the rinsing and the chemical liquid for the water-repellent processing are supplied to the upper surface 21a of the semiconductor member 21 from the nozzle unit 33 as illustrated in step S303 to step S306 of
As illustrated in
A tank 39 is provided in the manufacturing apparatus 5. The tank 39 is a container that contains the chemical liquid and the purified water. A lift unit 40 is provided as a portion of the drying mechanism in the manufacturing apparatus 5. The lift unit 40 can remove the holder unit 38 from the tank 39 and place the holder unit 38 inside the tank 39.
The microwave irradiation unit 34 is disposed above the tank 39.
An operation of this embodiment, i.e., a method for using the manufacturing apparatus 5 described above, will now be described.
As illustrated in
Then, as illustrated in step S201 of
Then, after an appropriate amount of time as illustrated in
Continuing as illustrated in
Then, after an appropriate amount of time as illustrated in
At this stage as illustrated in
Then, after the purified water filled into the interior of the tank 39 is discharged, as illustrated in
Thereby, as illustrated in
Thus, as illustrated in
Effects of this embodiment will now be described.
In the manufacturing apparatus 5 according to this embodiment, the multiple semiconductor members 21 can be processed at one time. For example, fifty of the semiconductor members 21 can be processed simultaneously. Therefore, the manufacturing unit cost of the semiconductor device can be reduced.
In the case where the water-repellent protective film 25 is formed on the front surface of the protruding patterns 20, the upper surfaces of the semiconductor members 21 can be in the state of being tilted with respect to horizontal; and the water 22 pushed out onto the upper surface 20a of the protruding patterns 20 can be removed by gravity.
Because the water 22 in the interior of the tank 39 is discharged when irradiating the microwaves 23, the water 22 inside the tank 39 can be prevented from boiling due to the microwaves 23. Otherwise, the effects of this embodiment are similar to those of the third embodiment described above.
Instead of discharging the water 22 in the interior of the tank 39 when irradiating the microwaves 23, the tank 39 may be shielded from the holder unit 38 such that the microwaves are not transmitted. Thereby, the water 22 inside the tank 39 can be prevented from boiling due to the microwaves 23.
The water-repellent processing of the second embodiment described above may be performed in the manufacturing apparatus 5 of this embodiment. In such a case, the purified water and the alcohol for the rinsing and the chemical liquid for the water-repellent processing are sequentially filled into the interior of the tank 39 as illustrated in step S303 to step S306 of
As illustrated in
An operation of this embodiment, i.e., a method for using the manufacturing apparatus 6 described above, will now be described.
The multiple semiconductor members 21 are mounted in the holder unit 38. A chemical liquid is filled into the interior of the tank 39.
Then, inside the chamber 35a as illustrated in step S201 of
Continuing as illustrated in step S202 of
At this stage as illustrated in
Then, as illustrated in step S203 of
Thereby, as illustrated in
Thus, as illustrated in
Effects of this embodiment will now be described.
In the manufacturing apparatus 6 according to this embodiment, the tank 39 and the microwave irradiation unit 34 are separately disposed in the chambers 35a and 35b. Therefore, the water 22 in the interior of the tank 39 can be prevented from boiling due to the microwaves 23.
In the manufacturing apparatus 6, the transfer unit 37 is disposed between the chamber 35a in which the tank 39 is disposed and the chamber 35b in which the microwave irradiation unit 34 is disposed. Thus, optionally adjusting at least one of the temperature, the humidity, and the pressure in the transfer unit 37, the semiconductor members 21 can be transferred from the chamber 35a to the chamber 35b while being wet even in the case where the tank 39 and the microwave irradiation unit 34 are separately disposed in the interiors of the chambers 35a and 35b. Therefore, the protruding patterns 20 do not collapse due to the water in the recesses 20c between the protruding patterns 20. Thereby, the semiconductor device can be downscaled because the collapse of the protruding patterns 20 can be suppressed even in the case where the fine protruding patterns 20 are formed. Otherwise, the effects of this embodiment are similar to those of the third embodiment described above.
The water-repellent processing of the second embodiment described above may be performed in the manufacturing apparatus 6 of this embodiment. In such a case, the purified water and the alcohol for the rinsing and the chemical liquid for the water-repellent processing are sequentially filled into the interior of the tank 39 as illustrated in step S303 to step S306 of
According to the embodiments described above, a method and an apparatus for manufacturing a semiconductor device that can be downscaled can be provided.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modification as would fall within the scope and spirit of the inventions.
Number | Date | Country | Kind |
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2012-017262 | Jan 2012 | JP | national |