WO1998037575A1

WO1998037575A1 - Surface treatment method and apparatus therefor

Info

Publication number: WO1998037575A1
Application number: PCT/JP1998/000629
Authority: WO
Inventors: Shoichi Terada; Yoshiaki Mori; Takuya Miyakawa
Original assignee: Seiko Epson Corporation
Priority date: 1997-02-24
Filing date: 1998-02-16
Publication date: 1998-08-27
Also published as: JP3653735B2

Abstract

A processing liquid (6) in a vessel (7) is heated by a heater (8) to evaporate, and the resulting vapor is controlled by a valve (9) and introduced into a treatment chamber (1) through a pipeline (10). In the treatment chamber (1), articles (5) being treated are placed on a heating plate (4) set on a conveying table (3). The articles being treated are heated by the heating plate so that a surface temperature of the articles being treated rises above, for example, a boiling point of the processing liquid. Surfaces of the articles being treated are exposed to vapor of the processing liquid introduced into the treatment chamber, so that surface refining such as improving of wettability and surface treatments such as ashing, etching and dry cleaning are performed depending upon a kind of the processing liquid used. Effects of the surface treatment can be enhanced by mixing an auxiliary gas into the vapor of the processing liquid and exposing the surfaces of the articles being treated to the mixed gas. The articles being treated, having been subjected to treatment are removed from the treatment chamber by driving the conveying table (3), subsequently introducing new articles being treated and repeating the surface treatment procedure.

Description

Itoda β surface treatment method and its equipment

The present invention relates to a surface treatment technique for removing inorganic or organic substances by etching and removing the surface of a material to be treated or improving the wettability by modifying the surface. Background art

Conventionally, with the development of semiconductor technology, various technologies developed for this kind of surface treatment are known. For example, as a method for removing organic substances from the surface of a material to be treated such as a substrate, an inkjet cleaning method using an organic solvent, or a dry cleaning method for removing organic substances by irradiating them with ozone, ultraviolet rays, or the like to cause a chemical reaction. is there. The above-mentioned jet cleaning method requires not only a step of performing a desired treatment, but also a rinsing step of removing a processing solvent and a step of drying a substrate, and also requires these additional steps. There was a problem that fixed equipment was required to execute the process, and the manufacturing cost was high.

In addition, in the conventional dry cleaning method, a sufficient cleaning effect cannot be expected because the ability to remove organic substances having a high molecular weight is low. In order to solve this problem, a method has been developed in which organic or inorganic substances are removed, and etching or asshing is performed using plasma generated in a vacuum. Special equipment such as vacuum chambers and vacuum pumps are required, complicating the entire equipment and increasing its cost due to its high cost. In addition, it takes a long time to reduce the pressure for discharging, so the processing capacity is low. For this reason, there was a problem that single-wafer processing was difficult and in-line processing was not possible.

On the other hand, for example, Japanese Patent Application Laid-Open Nos. Hei 2-2-271834, Hei 3-2-36475, Japanese Patent Laid-open Hei 5-23979, Hei 5-2795 As disclosed in, for example, Japanese Patent Publication No. 190, a plasma is generated by performing glow discharge under a pressure near the atmospheric pressure to uniformly or locally treat a large area of a material to be treated. Methods for performing surface modification such as etching, asshing, thin film formation, and hydrophilization are known. This In this case, although a vacuum device is not required, there is a problem in that discharge control for generating stable plasma and an electrode device are complicated.

Therefore, the present invention has been made to solve the above-described conventional problems, and the object thereof is to eliminate the need for an additional step for rinsing and drying the wet method, Also, it does not require expensive and large-scale equipment for vacuum and decompression, allows simple configuration and miniaturization of the equipment, and makes surface modification such as wettability improvement, asshing and etching relatively easy. Another object of the present invention is to provide a novel surface treatment method that can be performed at low cost.

Another object of the present invention is to provide a novel apparatus for realizing such a surface treatment method. Disclosure of the invention

According to one aspect of the present invention, there is provided a surface treatment method characterized in that a treatment liquid is heated to generate steam, and the surface of the heated object is exposed to the steam. The surface of the object to be treated is dry treated with the vapor of the treatment liquid, so that the wettability is improved by appropriately selecting the liquid to be used, without being limited by the shape or material of the object to be treated. Various types of surface modification, etching, asshing, and dry cleaning can be performed effectively in a wide range of fields. Also, it does not require any additional steps after processing such as rinsing and drying, which are necessary for ordinary wet processing, and does not require large vacuum equipment in conventional dry processing. The handling and processing operations are relatively simple, and the equipment and facilities for this can be simply configured, miniaturized, and processing costs can be significantly reduced. In addition, in-line processing can be performed easily.

If the object to be treated is heated so that its surface temperature is equal to or higher than the boiling point of the treatment liquid, there is no possibility that the treatment liquid will be cooled and liquefied on the surface of the object to be treated, so that the surface treatment can be performed effectively. It is convenient.

By heating the entire surface of the object to be treated, the entire surface can be treated, or only a desired portion can be selectively treated by heating only a part of the surface. . In addition, by arranging the object to be treated in an atmosphere containing the vapor of the treatment liquid, the surface can be easily exposed to the vapor and a desired surface treatment can be performed.

According to one embodiment, pure water, acidic water or alkaline water is used as the treatment liquid, and by exposing the treatment liquid to the vapor, the surface of the treatment object is modified to improve its wettability, or The surface can be ashed.

According to another embodiment, the surface of the workpiece can be etched by using an acid for the treatment liquid and exposing the treatment liquid to the vapor. In another embodiment, the wettability of the surface of the object to be treated can be improved by using an organic solvent for the treatment liquid. In still another embodiment, an oxidizing liquid may be used as the processing liquid to ashes the surface of the workpiece.

Further, according to the present invention, the auxiliary gas can be mixed with the vapor of the processing liquid, and the surface of the heated object can be exposed to the mixed gas, whereby the desired surface treatment can be performed more effectively. be able to.

According to an embodiment, pure water, acidic water, or alkaline water is used as the processing liquid, and an oxidizing gas is used as the auxiliary gas, and the processing liquid is exposed to a mixed gas of the vapor of the processing liquid and the oxidizing gas. By doing so, the wettability of the surface of the object to be treated can be improved.

According to another embodiment, by using an oxidizing liquid as the processing liquid and using an oxidizing gas as the auxiliary gas, the surface of the processing object is oxidized, or the wettability of the processing object surface is improved. Can be done.

In still another embodiment, the wettability of the surface of the object to be processed can be improved by using an organic solvent as the processing liquid and using a non-oxidizing gas as the auxiliary gas. Further, according to the present invention, in order to ashes the surface of the object to be treated, the method comprises at least two asshing steps, at least the last of which is a step of heating the treatment liquid to generate steam, A step of exposing the surface of the object to be treated to the vapor provides a surface treatment method. As a result, the surface of the non-processed material is first treated using a method having a high absorption rate, and then the organic residue remaining on the surface is subjected to a dry treatment using the vapor of a treatment liquid appropriately selected. Complete asshing can be performed relatively easily and efficiently, and as a result, the processing efficiency of asshing can be improved as a whole. According to another aspect of the present invention, the apparatus comprises: a steam generator that heats a processing liquid to generate steam; and a heating device that heats an object to be processed, wherein the surface of the object to be heated is converted to the steam. There is provided a surface treatment apparatus characterized by being exposed. Thereby, the surface treatment method of the present invention can be easily realized.

It is preferable that the surface treatment device further includes a housing that defines an atmosphere containing the vapor of the treatment liquid, and that the surface of the object is easily exposed to the vapor when the object is disposed in the housing. .

As the heating device, a heating plate on which the object is placed can be used to directly heat the object. In another embodiment, a hot air blower for sending hot air to the surface of the object to be processed can be used as a heating device, whereby a large number of objects to be processed are heated substantially uniformly and the surface is simultaneously treated. be able to.

In another embodiment, the heating device can be provided with a device K for irradiating infrared rays or ultraviolet rays, and further, by providing a mask for partially irradiating infrared rays or ultraviolet rays on the surface of the workpiece, A desired portion can be selectively and locally surface-treated.

Further, according to the present invention, in order to more effectively perform a desired surface treatment, it is advantageous to further include a gas supply device for supplying an auxiliary gas mixed with the vapor of the treatment liquid. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic sectional view showing a configuration of a first embodiment of a surface treatment apparatus to which the present invention is applied.

FIG. 2 is a sectional view showing a modification of the first embodiment.

FIG. 3 is a sectional view showing another modification of the first embodiment.

FIG. 4 is a schematic sectional view showing the configuration of a second embodiment of the surface treatment apparatus to which the present invention is applied.

FIG. 5 is a schematic sectional view showing the configuration of a third embodiment of the surface treatment apparatus to which the present invention is applied. BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 schematically shows the structure of a first embodiment of a preferred apparatus for performing the surface treatment method according to the present invention. The surface treatment apparatus includes a housing 2 defining a processing chamber 1 therein, in which a heating plate 4 set on a transfer table 3 is disposed, and a workpiece 5 is placed thereon. To be placed. The housing 2 is connected to a steam generator comprising a container 7 containing a processing liquid 6 and a heater 8 for heating the container. The upper part in the container 7 communicates with the inside of the processing chamber 1 via a pipe 10 provided with an introduction valve 9. Further, the housing communicates with the outside via an exhaust valve 11.

Various liquid types such as water (including pure water and tap water), acidic water, alkaline water, oxidizing liquid, organic solvent, and acid can be used for the treatment liquid 6 according to the desired surface treatment. it can. Specifically, considering the ease of handling and the impact on the environment, water is most preferred as the treatment liquid, but other than that, hydrogen peroxide, ethyl alcohol, hydrogen fluoride, etc. are used .

The processing liquid 6 inside the container 7 is heated and evaporated by the heater 8, and the vapor is fed into the processing chamber 1 via the pipe 10. The object 5 in the processing chamber 1 is heated to an appropriate temperature by the heating plate 4. The object to be treated is subjected to a desired surface treatment by exposing the exposed surface to the vapor of the treatment liquid 6 introduced into the treatment chamber 1. The processed object 5 is taken out of the processing chamber 1 by driving the transfer table 3, and then a new object is carried in, and the above-mentioned surface treatment step is repeated.

The amount of steam inside the processing chamber 1 is determined by the volume of the processing chamber, the method of setting the workpiece, the type and speed of surface treatment, and the amount of supply by the introduction valve 9 and the amount of discharge by the exhaust valve 11 And is controlled by adjusting

The temperature of the heating plate is adjusted so that the vapor of the processing liquid 6 does not liquefy on the surface of the workpiece 5. For example, when the surface temperature of the object to be treated is heated to a temperature equal to or higher than the boiling point of the treatment liquid, the liquefaction can be reliably prevented. In order to perform good surface treatment, it is preferable that the vapor in the processing chamber 1 maintain a vapor phase at least during the surface treatment, and that the inside of the housing 2 be cooled so as not to be liquefied. Therefore, separate heating means is provided, or the heating plate or heater is used to If the ring 2 itself is also configured to be heated, the efficiency of the surface treatment increases, which is advantageous.

Further, in order to efficiently perform the surface treatment of the present invention, it is effective to make the housing 2 as small as possible to reduce the volume of the processing chamber 1 or to increase the arrangement of objects to be processed in the processing chamber.

Experiments were performed using the surface treatment apparatus shown in Fig. 1 and various liquid types as the treatment liquid 6, and the following results were obtained.

(Example 1)

Pure water was used as the processing liquid 6, and steam was generated and introduced into the processing chamber 1. A thin plate of aluminum oxide was placed on the heating plate 4 as the treatment object 5, and the thin plate was treated for 5 minutes at a surface temperature of about 200 ^. As a result of measuring the contact angle of the aluminum oxide thin plate with a contact angle meter, the contact angle was 64 ° before the treatment, but was 6 ° after the treatment, and the wettability to water could be improved.

Further, the same experiment was performed by changing the treatment liquid 6 to ethyl alcohol. Similarly, the surface modification for improving the wettability of the surface of the aluminum oxide thin plate could be performed.

(Example 2)

In the same manner as in Example 1, pure water was used as the processing liquid 6, and steam was generated and introduced into the processing chamber 1. A silicon plate coated with an organic resist was placed on the heating plate 4 as the object 5 to be treated, and the resist plate was treated at a surface temperature of about 200 ° for 10 minutes. As a result, the resist could be removed from the silicon plate surface.

Further, a similar experiment was conducted by changing the treatment liquid 6 to an aqueous hydrogen peroxide solution, and it was also possible to perform the ashes for removing the resist on the silicon plate.

(Example 3)

Hydrogen fluoride was used as the processing liquid 6, and its vapor was generated and introduced into the processing chamber 1. A quartz plate was placed on the heating table 4 as the object 5 to be treated, and the surface temperature was set to 100 ° C. and the treatment was performed for 60 minutes. As a result, the surface of the quartz plate could be etched.

FIG. 2 schematically shows the structure of a modification of the surface treatment apparatus of FIG. In this modification, as a means for heating the object 5, a warm air blower 12 is provided in place of a heating plate so as to blow warm air downward to an upper portion of the chamber 1 to be processed. A plurality of plate-like workpieces 5 are vertically arranged on the mounting table 13 on the transfer table 3 so that the hot air can be easily hit. By using the warm air blower 12 in this manner, the plurality of workpieces 5 and the entire inside of the processing chamber 1 can be substantially uniformly heated, which is advantageous for batch processing.

Experiments were conducted on the surface treatment for improving the resilience, assembling and etching in the same manner as in Examples 1 to 3 above using the surface treatment apparatus shown in FIG. 2, and similarly good results were obtained. I was able to.

FIG. 3 schematically shows the structure of another modification of the surface treatment apparatus of FIG. In this modification, as a means for heating the object 5, an infrared irradiation device such as an infrared lamp with a reflecting plate is provided instead of a heating plate and provided downward on the upper part of the processing chamber 1. Immediately above the plate-shaped workpiece 5 placed horizontally on the transfer table 3, a mask 15 provided with an opening corresponding to a desired processing portion of the workpiece is arranged.

In this way, the steam of the processing liquid 6 is introduced into the processing chamber 1 from the steam generator while irradiating infrared rays so that only the desired processing portion is heated. The entire surface of the object 5 to be exposed is exposed to the vapor, but a desired surface treatment is locally performed only on the heated processing portion.

Instead of the infrared irradiation device 14, another heat radiation device such as an ultraviolet irradiation device can be used. The UV irradiation device has a feature that the temperature difference between the irradiated portion and the non-irradiated portion is larger than that of the infrared irradiation device, so that the local surface treatment can be performed more precisely.

Using the surface treatment apparatus shown in FIG. 3, experiments similar to those of Examples 1 to 3 were performed. As a result, each of the surface treatments for improving wettability, asshing, and etching was selected using a mask 15 of an object to be treated. Similarly good results could be obtained only in the part. FIG. 4 schematically shows the structure of a second embodiment of the surface treatment apparatus according to the present invention. This surface treatment device is provided with a gas inlet port 16 that branches off into a pipeline 10. By adjusting a valve 17, an auxiliary gas supplied from outside can be supplied. However, it differs from the apparatus of the first embodiment shown in FIG. 1 in that it can be mixed with the vapor of the processing liquid 6 and introduced into the processing chamber 1.

According to the present embodiment, a desired surface treatment can be more effectively performed by appropriately combining the treatment liquid 6 and the auxiliary gas and exposing the heated object to the mixed gas. . Various kinds of liquids described in the first embodiment can be used as the treatment liquid. An oxidizing gas or a non-oxidizing gas can be selected as the auxiliary gas depending on the purpose of the treatment.

For example, wettability can be improved by a combination of water or hydrogen peroxide and oxygen gas, or a combination of hydrogen peroxide or ethyl alcohol and nitrogen gas. Further, asshing can be performed by a combination of a hydrogen peroxide solution and an oxygen gas or a nitrogen gas. Furthermore, by using ozone as an auxiliary gas, the effect of assuring can be enhanced.

Experiments were performed using the surface treatment apparatus shown in Fig. 4 and combining some treatment liquids 6 and auxiliary gases. The following results were obtained.

(Example 4)

Pure water was used as the processing liquid 6, and oxygen gas was used as the auxiliary gas, and the mixed gas was introduced into the processing chamber 1. A thin plate of aluminum oxide was placed on the heating plate 4 as the object to be treated 5 and exposed to the mixed gas to perform a surface treatment. Thereby, the wettability of the aluminum oxide thin plate surface could be improved.

Further, when the same experiment was performed by changing the treatment liquid 6 to a hydrogen peroxide solution and using an oxygen gas in the same manner, the surface modification for improving the wettability was similarly performed. Also, when a similar experiment was performed with the treatment liquid 6 changed to ethyl alcohol and the auxiliary gas changed to nitrogen gas, the wettability was similarly improved.

(Example 5)

Hydrogen peroxide solution was used as the treatment liquid 6, and oxygen gas was used as the auxiliary gas, and a mixed gas thereof was introduced into the treatment chamber 1. A silicon plate coated with a resist, which is an organic substance, was placed on the heating plate 4 as the object 5 to be subjected to surface treatment. As a result, the resist was removed from the surface of the silicon plate, and asshing could be performed. FIG. 5 schematically shows the structure of a third embodiment of the surface treatment apparatus according to the present invention. In this surface treatment apparatus, a container 7 containing a treatment liquid 6 is arranged on a heating plate 4 in a treatment chamber 1 and a gas inlet 16 for supplementarily supplying a gas selected from the outside is provided. It differs from the devices of the first and second embodiments in that it is directly connected to the housing 2. According to the present embodiment, the vapor of the processing liquid 6 is generated directly in the processing chamber 1 with the above configuration, so that the vapor flows through the pipeline 10 as in the first and second embodiments. Since there is no danger of cooling during the passage, more efficient surface treatment is possible.

Although the present invention has been described in detail with reference to the preferred embodiments, the present invention provides a relatively simple process and apparatus by evaporating a treatment liquid and exposing the vapor to a heated object. The purpose of the present invention is to perform the intended surface treatment by using the method described above. In addition to the above-described embodiments, various changes and modifications can be made thereto.

For example, by jetting the vapor of the processing liquid using a nozzle equipped with a heater so as not to liquefy, a desired portion of the processing target can be locally surface-treated. Further, the heating apparatus shown in FIG. 2 or FIG. 3 can be used in place of the heating plate 5 in the surface treatment apparatus of the second or third embodiment.

In addition, particularly when a large amount of the organic substance to be removed adheres to the surface of the object to be treated, it is preferable to perform the at least two asshing steps. At this time, most of the organic substances are removed in a short time by using a method with a high association in the first assuring step, and at least the surface treatment method of the present invention described above in the last asssing step is used. By employing this method, the organic residues that could not be completely removed can be completely removed from the surface of the workpiece. As a result, it is possible to relatively and efficiently completely flush the surface of the object to be treated.

Further, by changing the treatment liquid in the course of the surface treatment according to the present invention, different surface treatments can be successively performed on the same treated material. Further, by changing the mask in the apparatus shown in FIG. 2, the same or different surface treatment can be continuously performed on different portions of the same workpiece.

Claims

The Range of Languages I 求

1. A surface treatment method comprising heating a treatment liquid to generate steam, and exposing the surface of the heated object to be exposed to the steam.

2. The surface treatment method according to claim 1, wherein the object to be treated is heated so that a surface temperature thereof is equal to or higher than a boiling point of the treatment liquid.

3. The surface treatment method according to claim 2, wherein the entire surface of the object is heated.

4. The surface treatment method according to claim 23, wherein the surface of the object is heated only partially.

5. The surface treatment method according to any one of claims 1 to 4, wherein the object is disposed in an atmosphere containing a vapor of the treatment liquid.

6. The surface treatment according to any one of claims 1 to 5, wherein the treatment liquid is pure water, acidic water or alkaline water, and improves the wettability of the object to be treated ^. Method.

7. The surface treatment method according to claim 1, wherein the treatment liquid is pure water, acidic water, or alkaline water, and the surface of the object to be treated is ashesed.

8. The surface treatment method according to claim 1, wherein the treatment liquid is an acid, and the surface of the object is etched.

9. The surface treatment method according to claim 1, wherein the treatment liquid is an organic solvent, and the wettability of the surface of the object is improved.

10. The surface treatment method according to any one of claims 1 to 5, wherein the treatment liquid is an oxidizing liquid, and the surface of the object to be treated is ashed.

11. The surface treatment according to any one of claims 1 to 4, wherein an auxiliary gas is mixed with the vapor of the treatment liquid, and the surface of the heated pretreatment is exposed to the mixed gas. Method.

12. The treatment liquid is pure water, acidic water or alkaline water, and the auxiliary gas is an oxidizing gas, and improves the wettability of the surface of the object to be treated. Item 11. The surface treatment method according to item 1.

13. The surface treatment method c according to claim 11, wherein the treatment liquid is an oxidizing liquid, and the auxiliary gas is an oxidizing gas, and the surface of the object to be treated is oxidized.

14. The surface treatment according to claim 11, wherein the treatment liquid is an oxidizing liquid, and the auxiliary gas is an oxidizing gas, and improves the wettability of the surface of the object to be treated. Method.

15. The surface treatment method according to item 11, wherein the treatment liquid is an organic solvent, and the auxiliary gas is a non-oxidizing gas, and the wettability of the surface of the workpiece is improved. .

16. A surface treatment characterized by comprising 2 [π · 1 or more ashing steps for ashing the surface of the object to be treated, wherein at least the last asshing step is the method according to claim 11. Method.

17. A steam generating device that heats the processing liquid to generate steam, and a heating device that heats the object to be processed, wherein the surface of the heated object to be processed is exposed to the steam. Characteristic surface treatment equipment.

18. The surface treatment according to claim 17, further comprising a housing that defines an atmosphere containing the vapor of the treatment liquid, wherein the object is disposed in the chamber.

19. The surface treatment device according to claim 17, wherein the heating device is a heating plate on which the object is placed.

20. The surface treatment device according to claim 17, wherein the heating device is a hot air blower for sending warm air to the surface of the workpiece.

21. The surface treatment device according to claim 17, wherein the heating device is a device that irradiates infrared rays or ultraviolet rays.

22. The surface treatment apparatus according to claim 21, further comprising a mask for partially irradiating infrared rays or ultraviolet rays to the surface of the workpiece.

23. The surface treatment according to any one of claims 17 to 22, further comprising a gas supply device for supplying an auxiliary gas mixed with the vapor of the treatment liquid.