JP2756502B2 - Ashing processing apparatus and method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to an ashing processing apparatus and method.

[Prior art]

In a semiconductor manufacturing process, for a substrate to be processed, such as a semiconductor wafer or an LCD substrate, which has been subjected to fine processing by etching a base through a photoresist film, the resist film used as a mask is removed from the surface of the substrate. There is a need to. For this purpose, an ashing process has been conventionally performed. Conventionally, in this ashing process, for example, a substrate to be processed, such as a semiconductor wafer or an LCD substrate, is housed in a chamber and heated by, for example, a resistance heater, and a predetermined processing gas, such as ozone-containing gas, is supplied to the chamber at normal pressure. As the atmosphere or the reduced pressure atmosphere, the above-described processing gas is applied to, for example, a photoresist of an organic polymer deposited on a substrate to be processed, and is ashed and removed.

[Problems to be solved by the invention]

However, the conventional ashing process in which a predetermined processing gas such as ozone is applied to a substrate to be processed such as a semiconductor wafer in a normal pressure atmosphere or a reduced pressure atmosphere has a disadvantage that the processing speed is relatively slow. Therefore, the present applicant has previously filed Japanese Patent Application No. 63-284638 (Showa
Ashing process in which a processing gas such as ozone is applied to a substrate to be processed in a high-pressure atmosphere to perform an ashing processing chamber, and the processing speed is increased by a high-density processing gas atmosphere. A method was proposed. Incidentally, the ashing process is performed by applying a reaction gas while heating the substrate to be processed. As a pretreatment, a preheating process for removing the solvent and the like in the photoresist and preheating the substrate to be processed in advance is performed. Apply. Through the preheating process, the throughput of the ashing process can be improved. Cooling for cooling the heated substrate to be processed is performed as a post-processing of the ashing process. For this reason, a preheating chamber is provided before the ashing chamber for the ashing process, and a cooling unit for cooling is provided after the ashing chamber. However, when these ashing chambers, preheating chambers, and cooling units are independent, in the ashing chamber, in the case of a single wafer type,
Each time a substrate to be processed is loaded into this reaction chamber,
There is a problem that the work of boosting and stepping down must be performed, and the throughput is deteriorated. SUMMARY OF THE INVENTION In view of the above-described drawbacks, an object of the present invention is to provide an ashing processing apparatus and method for performing an ashing process by reacting a processing gas under a high-pressure atmosphere and further improving throughput.

[Means for Solving the Problems]

An ashing processing apparatus according to the present invention includes a first opening / closing mechanism on a loading side of an object to be processed, and a second opening / closing mechanism on an unloading side of the processing object. An ashing processing chamber for processing below; and an ashing processing chamber provided on the loading side of the object to be processed in the ashing processing chamber in connection with the ashing processing chamber through the first opening / closing mechanism, and being loaded through a third opening / closing mechanism. A first preliminary chamber for pre-heating the object to be processed, and an ashing processing chamber provided on the unloading side of the object to be processed in the ashing processing chamber, the second opening and closing mechanism being connected to the ashing processing chamber; A second preparatory chamber for cooling the object to be processed and carrying out the cooled object to be processed through a fourth opening / closing mechanism, comprising: an ashing process in the ashing processing chamber; of The preliminary heating process and the cooling process in the second preliminary chamber are performed in a state in which each of the processing chambers is airtight by closing the opening / closing mechanism on the loading side and the transport side, respectively. The transfer of the object to be processed to the ashing processing chamber is performed by opening the first opening / closing mechanism after equalizing the pressures in the first preliminary chamber and the ashing processing chamber. The transfer of the object to be processed, which has been subjected to the ashing, to the second preliminary chamber is performed after the pressures in the ashing processing chamber and the second preliminary chamber are equalized.
The second opening / closing mechanism is opened to perform the operation. Further, in the ashing processing method according to the present invention, a first preliminary chamber for preheating the object to be processed is provided as a load lock chamber on the side of the ashing processing chamber where the object to be processed is carried in, and the object to be processed of the ashing processing chamber is provided. A second preparatory chamber for performing cooling as post-processing is provided as a load lock chamber on the carry-out side of the processing body, and the processing target is heated in the ashing processing chamber and a processing gas is caused to act in a high-pressure atmosphere. An ashing method for performing an ashing process, comprising: loading an object to be processed into the first preliminary chamber;
A first step of preheating the object to be processed in an airtight state of the preparatory chamber, and after the completion of the preparation for receiving the ashing processing chamber after the first step, With the pressure and the pressure in the ashing processing chamber being the same, a gate between the first preparatory chamber and the ashing processing chamber is opened, and the preheated object is transferred to the first preparatory chamber. A second step of carrying the wafer into the ashing processing chamber from the above; after the second step, closing a gate between the first preliminary chamber and the ashing processing chamber; A third step of ashing the body; and after the third step, the ashing processing chamber and the first ashing chamber are kept in a state where the pressure in the second preparatory chamber and the pressure in the ashing processing chamber are equalized. Gate between the spare room A fourth step of carrying out the opened and ashing-processed object from the ashing processing chamber to the second preliminary chamber, and bringing the ashing processing chamber into a state ready for receiving; Thereafter, a gate between the ashing processing chamber and the second preparatory chamber is closed, and the object subjected to the ashing processing in the second preparatory chamber is subjected to a cooling process. Carrying out, and setting the second spare room in the state of completion of the preparation for receiving, and repeating the first to fifth steps.
The first step, the third step, and the fifth step include:
It is characterized in that it is performed at times that overlap in time.

[Action]

Before and after the ashing processing chamber, a first preparatory chamber for preheating as pretreatment and a second preparatory chamber for cooling as postprocessing are provided in connection with the load lock chamber configuration. When the object to be processed is transported into the ashing processing chamber by setting the first preliminary chamber to a high pressure state, and when the object to be processed is transported from the ashing processing chamber to the second preliminary chamber, the high pressure is applied to the second preliminary chamber. By performing the treatment in an atmosphere, the object to be processed can be processed in a state where the pressure in the ashing processing chamber is equalized. Therefore, the pressure in the ashing processing chamber does not need to be increased or decreased for each object to be processed, and the throughput can be improved.

【Example】

Hereinafter, an embodiment of the ashing processing apparatus of the present invention,
This will be described with reference to FIG. 1 and FIG. 2 for explaining the operation. In the ashing main chamber 1, a heating plate 3 on which a substrate such as a semiconductor wafer 2 is mounted as an object to be processed, and a gas diffusion plate 4 facing the heating plate 3.
Is provided. The heating plate 3 is made of a metal plate made of, for example, SUS or aluminum, and has, for example, a built-in resistance heating heater (not shown) as heating means, and is configured to be able to heat a substrate such as the semiconductor wafer 2 mounted on the upper surface thereof. ing. The heating plate 3 is provided with a plurality of pins, for example, three pins 15 connected to the substrate lifting / lowering device 14 so as to penetrate the heating plate 3, and when loading / unloading a substrate such as the semiconductor wafer 2. The pins 15 hold a substrate such as the semiconductor wafer 2. Further, a diffusion plate elevating device 5 is connected to the gas diffusion plate 4 so that a distance between the gas diffusion plate 4 and a substrate to be processed such as the semiconductor wafer 2 can be set to a desired distance. Although not shown, a processing gas (a gas containing ozone) is provided in the gas diffusion plate 4.
A large number of alternately provided ejection slits (not shown) as an example of an opening for ejecting exhaust gas, and a plurality of exhaust slits (not shown) as an example of an opening for exhausting exhaust gas. A pressure increasing device 7 is connected to the ejection slit via a flow rate adjusting device 6. This booster 7
For example, a booster pump such as a plunger pump, a bellows pump, and a diaphragm pump can be processed.
The booster 7 has an ozone generator 9 for generating ozone from oxygen supplied from the oxygen supply device 8.
And a secondary gas excitation device 11 that excites the secondary gas supplied from the secondary gas supply device 10. As the ozone generator 9, for example, a device that generates ozone by silent discharge, corona discharge, glow discharge, or the like can be used. On the other hand, the exhaust slit of the gas diffusion plate 4 is connected to, for example, a factory exhaust system or the like via a pressure adjusting device 12 and an exhaust gas abatement device 13. A preheating chamber 30 and a cooling unit are provided on both sides of the main chamber 1 for ashing.
40 are configured as a load lock chamber. The preheating chamber 30 is provided in front of the ashing main chamber 1 when viewed from the direction of transport of the substrate such as the semiconductor wafer 2 indicated by an arrow, and includes a cooling unit.
Numeral 40 is provided after the main chamber 1 for ashing. Load / unload opening / closing mechanisms 16 and 17 are provided between the ashing main chamber 1 and the preheating chamber 30 and between the ashing main chamber 1 and the cooling unit 40. A loading opening / closing mechanism 31 is provided on the side of the preheating chamber 30, and further includes a cooling unit.
An unloading opening / closing mechanism 41 is provided on the side of 40. Further, the pressure increasing devices 32 and 42 are connected to the preheating chamber 30 and the cooling unit 40, respectively, so that the pressures in the preheating chamber 30 and the cooling unit 40 can be adjusted to high pressures. In the preheating chamber 30, a heating plate 33 configured similarly to the above-described heating plate 3 is provided. Then, similarly to the inside of the ashing main chamber 1, a plurality of, for example, three pins 35 connected to the substrate lifting / lowering device 34.
This is provided so as to penetrate the heating plate 33, and is configured to hold the semiconductor wafer on these pins 35 when a substrate such as the semiconductor wafer 2 is loaded / unloaded. In the cooling unit 40, the cooling plate 43
And a plurality of, for example, three pins 45 connected to the substrate elevating device 44 are provided so as to penetrate the cooling plate, and load and load a substrate such as the semiconductor wafer 2.
At the time of unloading, the semiconductor wafer is held on these pins 45. In addition, a substrate transfer device, a sender, and the like (not shown) are provided beside the loading opening / closing mechanism 31 on the side of the preheating chamber 30. In the apparatus configured as described above, in this embodiment, ashing of a substrate such as the semiconductor wafer 2 is performed as follows. That is, first, a substrate such as the semiconductor wafer 2 is transferred from a sender (not shown) to a side of the loading opening / closing mechanism 31 of the preheating chamber 30 by a transfer device (not shown) (Step 101 in FIG. 2). Then, in advance, the heating plate in the preheating chamber 30
33 is heated to a predetermined temperature, for example, 50 to 150 ° C., and preheating conditions are adjusted (the same as 102). When the preheating conditions are adjusted, the load opening / closing mechanism 31 is opened and the semiconductor wafer 2 and the like are put into the preheating chamber 30. Is carried in and placed on the heating plate 33 (the same as 103). At this time, the pins 35 are previously projected above the heating plate 33 by the substrate lifting device 34. Then, the transfer arm of the transfer device is inserted, a substrate such as the semiconductor wafer 2 is placed on the pins 35, and after the transfer arm is retracted, the pins 35 are lowered to place the semiconductor wafer 2 or the like on the heating plate 33. Is placed. Then, the substrate such as the semiconductor wafer 2 is subjected to the above-described preheating process under a reduced pressure of about 10 Torr (same as 104). By this preheating process,
For example, the solvent in the photoresist applied to the surface of the substrate such as the semiconductor wafer 2 can be efficiently removed in a short time, and by heating the substrate in advance, the substrate heating time in the ashing process described below can be reduced. Can be shortened. This preheating process is performed, for example, for several minutes. Thereafter, the preheating chamber is operated by the pressure increasing device 32.
The inside of 30 is kept at the same pressure as the inside of the ashing main chamber 1 during the ashing process, for example, about 2 to 20 at. When the preheating process is completed (105 in the same example) and the preparation for receiving the next substrate such as the wafer 2 is completed in the ashing main chamber 1, that is, the ashing process for the previous substrate such as the semiconductor wafer 2. Is completed, the processed substrate is carried out to the cooling unit 40, and the ashing main chamber 1 is in a standby state (the internal pressure is the same as that in the preheating chamber 30: 2 to 20 at). In the case (Id., 106), load
The unloading opening / closing mechanism 16 is opened, and the substrate such as the semiconductor wafer 2 which has been subjected to the preheating process is carried into the ashing main chamber 1 (107 in the same). At the time of loading, in the ashing main chamber 1,
The gas diffusion plate 4 is raised by the diffusion plate lifting device 5 in advance, and a sufficient gap is provided between the heating plate 3 and the gas diffusion plate 4. Then, the pins 15 are made to protrude above the heating plate 3 by the substrate lifting device 14, and a substrate such as the semiconductor wafer 2 is transferred onto the pins 15 from a substrate transport device (not shown). Thereafter, the transfer arm of the substrate transfer device is retracted, the pins 15 are lowered by the substrate lift device 14, the substrate such as the semiconductor wafer 2 is placed on the heating plate 3, and the gas diffusion plate is moved by the diffusion plate lift device 5. An interval between the substrate 4 and a substrate such as the semiconductor wafer 2 is set to a predetermined interval. At this time, the pressure in the main chamber 1 is the same as that during the ashing process as described above, and the heating plate 3 is heated to a predetermined temperature, for example, 150 to 250 ° C. Therefore, the pressure in the preheating chamber 30 and the pressure in the ashing main chamber 1 are equal,
Since there is no change in the pressure in the main chamber 1, it is in a state where the process can immediately proceed to the ashing process. Thus, when the substrate such as the semiconductor wafer 2 is carried into the ashing main chamber 1, the load / unload opening / closing mechanism 16 is closed. In the preheating chamber 30, the gas under pressure is exhausted to the outside of the chamber, and the pressure is reduced to normal pressure. Then, the load opening / closing mechanism 31 is opened, and the next substrate such as the semiconductor wafer 2 is carried in. Then, the above-described preheating process is performed. On the other hand, in the ashing main chamber 1, the substrate such as the semiconductor wafer 2 is heated by the heating plate 3, the gas containing ozone supplied from the ozone generator 9, and the excitation supplied from the secondary gas excitation device 11. The increased secondary gas is pressurized to, for example, about 2 to 20 atm by the pressurizing device 7, and is adjusted to a flow rate of, for example, 3 to 30 / min by the flow control device 6, and the semiconductor wafer 2 is discharged from the ejection slit of the gas diffusion plate 4. While squirting toward the substrate, etc.
The air is exhausted from the exhaust slit and high-pressure ashing is performed (108 in the same). The ozone remaining in the exhaust gas is removed by the exhaust gas abatement system.
After being decomposed by 13, it is sent to the factory exhaust system. In addition, the pressure in the ashing main chamber 1 is reduced by the pressure adjusting device 12 to the predetermined pressure (for example, 2 to 20).
Ata) is performed while controlling so as to be maintained. When the end of the high-pressure ashing process is detected, for example, by detecting the end of the process, for example, by detecting the process in a predetermined time or the component in the exhaust gas (109, the same).
High-pressure ashing end processing is performed (same as 110). Then, when the cooling chamber 40 is in a state where preparation for receiving the next substrate such as the semiconductor wafer 2 is completed,
In other words, the substrate such as the previous semiconductor wafer 2 is carried out through the unloading opening / closing mechanism 41 after the cooling process is completed, and the pressure in the chamber 40 is adjusted by the pressure adjusting device 42 to the ashing main. If it is in the same state as in chamber 1 (11, 11
1), the load / unload opening / closing mechanism 17 is opened,
The substrate, such as the semiconductor wafer 2, on which the ashing process has been completed, is carried into the cooling chamber 40 (112 in the cooling chamber).
Also in this case, the pins 45 are protruded by the elevating device 44, and the loaded substrate is placed thereon. Thereafter, the pins 45 are lowered by the elevating device 44, and the substrate is placed on the cooling plate 43. Is placed. Then load
The unloading opening / closing mechanism 17 is closed, and the ashing main chamber 1 is in a state ready for receiving a next substrate such as a semiconductor wafer 2 from the preheating chamber 30. On the other hand, in the cooling unit 40, the substrate such as the semiconductor wafer 2 is subjected to a cooling process in the high-pressure state and cooled (113 in the same). Then, when the cooling process is completed (at 114),
The substrate such as the semiconductor wafer 2 is transferred to a receiver (not shown) by a transfer device (not shown) (115 in the same drawing), and the processing for one substrate such as the semiconductor wafer 2 is completed. In order to prevent contamination in the ashing main chamber 1, the pressure in the ashing main chamber 1 should be set higher than the pressure in the processing chamber of the preheating chamber 30 and the cooling unit 40. Is preferred. In the embodiment, the case where the photoresist film is used as the object to be ashed has been described. However, the present invention can be applied to various kinds of materials that can be removed by oxidation, such as ink removal and solvent removal. Further, the gas containing ozone as the gas for ashing treatment is not limited to oxygen, and a gas that does not react with ozone, particularly an inert gas such as N ₂ , Ar, or Ne, may be used by containing ozone. In addition, the object to be processed is not limited to a semiconductor wafer, and it goes without saying that various types of photomasks, printed substrates, and the like provided on glass substrates can be applied in addition to LCD substrates.

【The invention's effect】

As described above, in the ashing processing apparatus according to the present invention, since the processing is performed in the processing main chamber under the high-pressure processing gas atmosphere, the processing can be performed in a short time in the high-density processing gas atmosphere, and the processing can be performed in a short time. Before and after the main chamber, for example, the ashing main chamber, a pre-heating chamber as a pre-processing chamber and a cooling cooling unit as a post-processing chamber are configured as a load lock and connected, so the minimum substrate transfer time Can perform the ashing process, and the throughput can be improved.

[Brief description of the drawings]

FIG. 1 is a view showing the configuration of an embodiment of an ashing processing apparatus according to the present invention, and FIG. 2 is a view for explaining the processing procedure. 1; Ashing main chamber 2; Semiconductor wafer 3,33; Heat plate 4; Gas diffusion plate 7,32,42; Booster 15,35,45; Pins 16,17; Load / unload opening / closing mechanism 30; Preheat Chamber 31; loading mechanism 40; cooling unit 41; unloading mechanism 43; cooling plate

Claims (2)

(57) [Claims] An object is provided with a first opening / closing mechanism on a loading side of an object to be processed and a second opening / closing mechanism on an unloading side of the object to be processed to process the loaded object in a high-pressure atmosphere. An ashing processing chamber to be processed, and the processing target being provided on the loading side of the ashing processing chamber with the object to be processed being connected to the ashing processing chamber through the first opening / closing mechanism and being loaded through a third opening / closing mechanism. A first preparatory chamber for preheating the body, and an ashing processing chamber provided on the unloading side of the ashing processing chamber with the ashing processing chamber through the second opening / closing mechanism; And a second preparatory chamber for carrying out the cooled object through a fourth opening / closing mechanism, comprising: an ashing process in the ashing process chamber;
The pre-heating process in the pre-chamber and the cooling process in the second pre-chamber are performed in a state where the opening / closing mechanisms on the loading side and the unloading side are closed to make each processing chamber airtight. The transfer of the object to be processed, which has been pre-heated in the chamber, to the ashing processing chamber is performed by opening the first opening / closing mechanism after equalizing the pressure in the first pre-chamber and the ashing processing chamber, The transfer of the object to be processed, which has been subjected to the ashing process in the ashing processing chamber, to the second preliminary chamber is performed after equalizing the pressure in the ashing processing chamber and the pressure in the second preliminary chamber. An ashing processing device characterized in that it is opened and performed. 2. An ashing processing chamber, on the loading side of an object to be processed,
A first pre-chamber for pre-heating the object is provided as a load lock chamber, and a second pre-chamber for performing cooling as post-processing is load-locked on the unloading side of the object in the ashing processing chamber. An ashing method for heating the object to be processed and performing an ashing process by applying a processing gas under a high-pressure atmosphere, wherein the object to be processed is carried into the first preliminary chamber; A first step of preheating the object to be processed in an airtight state of the first preparatory chamber; and after the first step, waiting for completion of the preparation for receiving the ashing processing chamber. The gate between the first preparatory chamber and the ashing processing chamber is opened in a state where the pressure in the ashing processing chamber is the same as the pressure in the ashing processing chamber, and the preheated object is subjected to the first preparatory processing. From the room A second step of loading the object into the ashing processing chamber; after the second step, closing a gate between the first preliminary chamber and the ashing processing chamber; Ashing process chamber, and after the third process, the ashing process chamber and the first ashing process are performed in a state where the pressure in the second preparatory chamber and the pressure in the ashing process chamber are equalized. Opening a gate between the preparatory chamber and the ashing processing object, and carrying out the ashing-processed object from the ashing processing chamber to the second preparatory chamber, and setting the ashing processing chamber to the state ready for receiving. And after the fourth step, the ashing processing chamber and the second
The gate between the second preliminary chamber and the second preliminary chamber is closed, and the ashing-processed object is cooled in the second preliminary chamber, and then is carried out of the second preliminary chamber. A fifth step of bringing the apparatus into a state of completion of the preparation for acceptance, wherein the first to fifth steps are repeated, and the first step, the third step, and the fifth step are performed in time. An ashing processing method, which is performed in a time overlapping with the above.