KR100693248B1 - Drying apparatus used in manufacturing semiconductor devices - Google Patents

Abstract

The present invention is a device for drying a wafer, the device having a dryer and a steam supply for supplying alcohol vapor therein. The steam supply part has a first steam generator for generating alcohol vapor by a bubbling method and a second steam generator for generating alcohol vapor by heating of the alcohol liquid. Alcohol vapor is supplied from the first steam generator to the dryer when the drying process is performed by the Marangoni drying method in the dryer, and alcohol vapor is supplied from the second steam generator to the dryer when the drying process is performed by the spray drying method.

Alcohol vapor, IPA, dry, marangoni, spray

Description

DRYING APPARATUS USED IN MANUFACTURING SEMICONDUCTOR DEVICES

1 shows an example of a drying apparatus of the present invention;

2 is a view schematically showing a preferred example of the steam supply of FIG.

3 is a view illustrating a process in which a low concentration of alcohol vapor is supplied to a dryer in the steam supply unit of FIG. 2; And

4 is a view showing a process in which a high concentration of alcohol vapor is supplied to the dryer in the steam supply of FIG.

Explanation of symbols on the main parts of the drawings

120: dryer 200: steam supply

220: first steam generator 222: first body

224; First Gas Supply Pipe 226: First Steam Supply Pipe

240: second steam generator 242: second body

244: alcohol liquid supply pipe 246: second steam supply pipe

248: carrier gas supply pipe 260: second gas supply pipe

280: controller

The present invention relates to an apparatus for manufacturing a semiconductor device, and more particularly to an apparatus for drying a semiconductor substrate.

When fabricating a semiconductor substrate such as a wafer into an integrated circuit, a process of cleaning the semiconductor wafer is required to remove residual chemicals, small particles, contaminants, and the like, which occur during the manufacturing process. The cleaning process of a semiconductor wafer can be divided into a chemical processing process, a rinsing process, and a drying process. The chemical liquid treatment process is a process of etching or peeling contaminants on a wafer by a chemical reaction using a chemical liquid such as hydrofluoric acid. The rinsing process is a process of washing the chemically processed semiconductor wafer with deionized water. It is a process of drying a wafer.

As a device for performing a drying process, a spin dryer has been conventionally used. However, as a spin dryer using a centrifugal force has a complicated integrated circuit, it is difficult to completely remove water droplets remaining on the wafer, and the wafer is contaminated by vortices generated by high-speed rotation of the wafer. Recently, a method of drying a semiconductor substrate using alcohol vapor such as isopropyl alcohol (IPA) has been used. One of these is the Marangoni drying method which dries the substrate by the Marangoni effect using the low surface tension of the IPA vapor. The other is the IPA vapor after supplying the IPA vapor after exposing the wafer to air. It is spray drying method to substitute.

The drying apparatus using the IPA described above has a dryer in which a process is performed, and a guide is provided in the dryer for accommodating about 50 wafers simultaneously. The dryer is connected to an alcohol steam generator which supplies IPA steam. In the Marangoni drying method, since the alcohol vapor generator generates IPA vapor by bubbling, a relatively low concentration (about 0.1%) of alcohol vapor is supplied to the dryer. In the case of the spray drying method, the alcohol vapor generator generates IPA vapor by heating the IPA liquid supplied into the tank, thereby supplying a relatively high concentration (about 20%) of the alcohol vapor to the dryer.

In general, the drying apparatus is connected to an alcohol vapor generator that generates IPA steam only by either bubbling or pumping. However, the semiconductor process does not generate a drying defect only when the drying process is performed using a specific drying method according to the process step. Therefore, when a problem occurs in the drying apparatus, it is not possible to use a drying apparatus that performs the drying process using another drying method installed in close proximity, and moves to a place where the apparatus that performs the drying process is performed by the same drying method. It must be done.

In the case of the spray drying method, the IPA liquid is supplied to the tank by the pump. Therefore, it is impossible to precisely control the milliliter (ml), and the supply range of the alcohol liquid when the pump is used is narrow, so that the supply range of the IPA concentration that can be supplied to the dryer is narrow.

It is an object of the present invention to provide a drying apparatus capable of supplying alcohol vapor of various concentration ranges into a dryer when performing a drying process using alcohol vapor.

In addition, an object of the present invention is to provide a drying apparatus capable of precisely controlling the concentration of alcohol vapor supplied to the dryer, and capable of supplying a wide range of alcohol vapor to the dryer.

In order to achieve the above object, the present invention drying apparatus includes a dryer for drying a substrate and a steam supply unit for supplying alcohol vapor to the dryer. The steam supply unit has a first steam generator for generating low concentration alcohol vapor and supplying it to the dryer and a second steam generator for generating high concentration alcohol vapor and supplying it to the dryer.

The first steam generator has a first body in which alcohol liquid is stored, and is generated in the first body by the first gas and the first gas supply pipe for supplying the first gas into the alcohol liquid filled in the first body. A first steam supply line is provided for supplying alcohol vapor to the dryer.

The second steam generator is heated by a heater and has a second body for providing a space for supplying alcohol liquid, wherein the second body is an alcohol liquid supply pipe for supplying alcohol liquid into the second body and the second body. A second steam supply pipe is provided for supplying the alcohol vapor generated therein to the dryer. A transport gas supply pipe for supplying a transport gas for transporting alcohol vapor generated in the second body to the dryer may be connected to the second body.

Preferably, a dispensing nozzle is attached to the tip of the alcohol liquid supply pipe connected to the second body, and the alcohol liquid is supplied into the second body in a mist state through the spray nozzle.

In one embodiment, the alcohol liquid supply pipe is connected to the first body of the first steam generator, a second gas supply pipe for supplying a second gas to the upper portion of the alcohol liquid in the first body is provided, the second The alcohol liquid filled in the first body by the pressurization of the gas is introduced into the second body through the first alcohol liquid supply pipe.

In addition, when the process of drying the substrate using the Marangoni effect in the dryer is performed, the alcohol vapor generated in the first body is supplied to the dryer, and the alcohol vapor is directly injected onto the substrate in the dryer. When the process of drying the substrate is performed by replacing the liquid attached on the substrate with alcohol vapor, alcohol vapor generated in the second body may be supplied to the dryer.

Hereinafter, an embodiment of the present invention will be described in more detail with reference to FIGS. 1 to 4. The embodiments of the present invention may be modified in various forms, and the scope of the present invention should not be construed as being limited by the embodiments described below. This embodiment is provided to more completely explain the present invention to those skilled in the art. Therefore, the shape of the elements in the drawings are exaggerated to emphasize a clearer description.

In this embodiment, a batch drying apparatus that performs a drying process on a plurality of wafers at the same time will be described as an example. However, the technical idea of the present invention is also applicable to a sheet type drying apparatus that performs a drying process for one wafer as disclosed in Korean Patent Laid-Open Publication No. 2004-028385.

1 shows schematically a drying apparatus 1 according to a preferred embodiment of the invention. Referring to FIG. 1, the drying apparatus 1 has a dryer 120 that performs a drying process on wafers (not shown) and provides a closed space from the outside. The dryer 120 has a body 120a which provides a space in which the wafer is accommodated and a cover 120b that opens and closes the open upper portion of the body 120a during wafer transfer. Body 120a has inner tub 122 and outer tub 124. A support 140 for supporting wafers is installed in the lower portion of the inner tank 122. The support 140 has a plurality of slots to accommodate approximately 50 wafers simultaneously. A cleaning solution supply nozzle 160 for supplying a cleaning solution to the inner tank 122 is disposed below the support 140 in the inner tank 122. The cleaning solution may be a chemical solution containing hydrofluoric acid or ammonia in the chemical solution treatment process, and may be deionized water in the rinsing process. An outlet 127, which is a passage through which deionized water flows, is formed at an upper end of the side wall of the inner tank 122, and an outer tank 124 is coupled to an outer wall of the inner tank 122. Deionized water overflowing from the inner tank 122 through the outlet 127 during the rinsing process is accommodated in the outer tank 124 and is discharged to the outside through the discharge pipe 125 connected to the bottom surface of the outer tank 124. The discharge pipe 125 is provided with an on-off valve 125a for opening and closing the passage. The bottom surface of the inner tank 122 is formed in the shape of a Paul (bowl), the discharge pipe 123 for discharging the cleaning liquid filled in the inner tank 122 is connected to the bottom center. The discharge pipe 123 may be provided with an on-off valve for opening and closing the inner passage or a flow control valve 123a for adjusting the flow rate. Emission may be natural by gravity or may be forced out by a pump or the like.

A gas injection nozzle 180 for injecting alcohol vapor into the inner tank 122 is disposed above the inner tank 122. The gas injection nozzle 180 receives the alcohol vapor from the steam supply unit 200 and injects it into the dryer 120. The steam supply unit 200 will be described later. In addition, although not shown, the dryer 120 is connected to a drying gas supply pipe which supplies heated nitrogen gas into the dryer 120 to remove deionized water and alcohol vapor remaining on the wafer after drying by the alcohol vapor is completed. do.

As alcohol, isopropyl alcohol (hereinafter referred to as IPA) is preferably used, and optionally ethylglycol, monopropanol, 2-propanol, tetrahydrofurane ), 4-hydroxy-4-methyl-2-pentanol, 4-butanol, 2-butanol, 2-methanol, methanol, ethanol, Acetone or dimethylether can be used. The alcohol vapor is carried into the dryer 120 by a carrier gas such as nitrogen gas. When the deionized water attached to the wafer is replaced with IPA vapor, heated nitrogen gas is supplied into the dryer 120 to remove the IPA vapor on the wafer.

The drying process is performed by forming a layer of IPA liquid on the surface of the wafer and the deionized water, using a marangoni drying method of drying the wafers using the Marangoni effect, or exposing the wafer to air and isopropyl alcohol inside the dryer 120. It is formed by a spray drying method in which a wafer is dried by forming a vapor atmosphere so that the moisture remaining on the wafer surface is replaced with isopropyl alcohol vapor.

2 is a view schematically showing a preferred example of the steam supply unit 200 in the apparatus of FIG. 2, the steam supply unit 200 has a first steam generator 220, a second steam generator 240, and a controller 280. The first steam generator 220 supplies a relatively low concentration (molar concentration of 5% or less) alcohol vapor to the dryer 120, the second steam generator 240 is a relatively high concentration (molar concentration 10-30%) of the alcohol vapor It is supplied to the dryer (120). When the drying process is performed in the dryer 120 by the Marangoni drying method, alcohol vapor is supplied to the dryer 120 by the first steam generator 220, and the drying process is performed by the spray drying method in the dryer 120. When performed, alcohol vapor is supplied to the dryer 120 by a second steam generator 240.

The first steam generator 220 has a tubular first body 222 in which a space sealed from the outside is formed. The isopropyl alcohol liquid is filled in the first body 222 at a predetermined height. The first gas supply pipe 224 is coupled to the bottom surface of the first body 222. The tip of the first gas supply pipe 224 is located in the alcohol liquid. The first gas supply pipe 224 supplies the first gas into the alcohol liquid to generate bubbles in the alcohol liquid. As the first gas, nitrogen gas or inert gas is used. Isopropyl alcohol around the nitrogen bubble evaporates due to its high volatility, mixes with nitrogen and evaporates above the alcoholic liquid. The first steam supply pipe 226 is connected to the upper surface of the first body 222. Isopropyl alcohol vapor in the first body 222 is supplied to the dryer 120 through the first steam supply pipe 226 along with the nitrogen gas. The first gas supply pipe 224 and the first steam supply pipe 226 are provided with valves 224a and 226a for opening and closing the inner passage and adjusting the flow rate. As the valves 224a and 226a, valves which can be electrically controlled by the controller 280 are used. The concentration of the alcohol vapor supplied to the dryer 120 by the first steam generator 220 is controlled within a predetermined range by the amount of the first gas supplied into the alcohol liquid filled in the first body 222.

The second steam generator 240 has a tubular second body 242 in which a space sealed from the outside is formed. A heater 242a for heating the inside of the second body 242 is installed around the outer wall of the second body 242. The heater 242a may have a coil shape or a plate shape. The side surface of the second body 242 and the bottom surface of the first body 222 are connected by the alcohol liquid supply pipe 244. An injection nozzle 250 for spraying the alcohol liquid flowing through the alcohol liquid supply pipe 244 into the second body 242 is installed at the end of the alcohol liquid supply pipe 244. The alcohol liquid is supplied to the second body 242 in a mist state. The alcohol liquid in the mist state in the second body 242 is changed into alcohol vapor by the heater 242a. The bottom surface of the second body 242 is connected to the carrier gas supply pipe 248 for supplying a carrier gas, such as nitrogen gas or inert gas, into the second body 242, the first surface of the second body 242 Two steam supply pipes 246 are combined. The alcohol vapor generated in the second body 242 is supplied into the dryer 120 through the second steam supply pipe 246 by the carrier gas.

The alcohol liquid supply pipe 244 is connected to the first body 222, and the alcohol liquid is supplied from the first body 222 to the second body 242. The second gas supply pipe 260 for supplying a second gas to the upper portion of the alcohol liquid in the first body 222 is coupled to the upper surface of the first body 222. The second gas pressurizes the alcohol liquid filled in the first body 222, whereby the alcohol liquid flows into the second body 242 through the alcohol liquid supply pipe 244. Each of the second gas supply pipe 260, the alcohol liquid supply pipe 244, and the second steam supply pipe 246 is provided with valves 260a, 244a, and 246a for opening and closing the internal passage and adjusting the flow rate. The valves 260a, 244a, and 246a are preferably valves electrically controllable by the controller 280. The concentration of the alcohol vapor supplied to the dryer 120 by the second steam generator 240 is controlled within a predetermined range by the amount of the second gas supplied through the second gas supply pipe 260.

Unlike the above, the alcohol liquid supplied to the second body 242 may be supplied using a pump. However, it is preferable to use a method of pressurizing the alcohol liquid with nitrogen gas as described above so that the alcohol liquid supplied to the second body 242 can be supplied in a wide range and precisely.

Next, a method of supplying the alcohol vapor to the dryer 120 will be described with reference to FIGS. 3 and 4. In FIG. 2 and FIG. 3, the internally filled valve indicates a state in which the internal passage is closed to block the flow of the fluid, and the internally filled valve indicates the state in which the internal passage is opened for the fluid to flow. First, the drying method performed in the dryer 120 is determined. When the drying process is performed by the Marangoni drying method, as shown in FIG. 3, the controller 280 opens the valves 224a and 226a installed in the first gas supply pipe 224 and the first steam supply pipe 226. It opens and closes the valves 260a, 244a, 246a provided in the 2nd gas supply pipe 260, the alcohol liquid supply pipe 244, and the 2nd vapor supply pipe 246. As shown in FIG. Alcohol vapor evaporated together with the bubbles in the first body 222 is supplied to the dryer 120 to perform a drying process. When the drying process is performed by the spray drying method, as shown in FIG. 4, the controller 280 is a valve installed in the second gas supply pipe 260, the alcohol liquid supply pipe 244, and the second steam supply pipe 246. 260a, 244a and 246a are opened, and the valves 224a and 226a provided in the first gas supply pipe 224 and the first steam supply pipe 226 are closed. The alcohol liquid flows through the alcohol liquid supply pipe 244 by the pressure of the second gas introduced into the first body 222, and is sprayed into the second body 242 in the mist state by the nozzle 250. The alcohol vapor evaporated by the heater 242a in the second body 242 is supplied to the dryer 120 to perform a drying process.

In the present invention, since the steam generator for supplying the alcohol vapor at low concentration and the steam generator for supplying the alcohol vapor at high concentration are respectively connected to the dryer, it is possible to perform the drying process by spraying as well as marangoni drying in one dryer. .

In addition, the present invention is because the supply of the alcohol liquid in the steam generator for supplying the alcohol vapor at a high concentration is made by pressurizing the alcohol liquid with nitrogen gas, it is possible to supply a precisely adjusted alcohol liquid, a wide range of alcohol from the steam generator Steam can be supplied.

Claims (10)

A dryer for drying the substrate; Including a steam supply for supplying alcohol vapor to the dryer, The steam supply unit, A first steam generator for generating a low concentration of alcohol vapor and supplying it to the dryer; And And a second steam generator for generating a high concentration of alcohol vapor and supplying it to the dryer. The method of claim 1, The first steam generator, A first body in which alcoholic liquid is stored; A first gas supply pipe for supplying a first gas into the alcohol liquid filled in the first body; And a first steam supply pipe for supplying the alcohol vapor generated in the first body by the first gas to the dryer. The method of claim 2, The second steam generator, A second body heated by the heater and providing a space to which the alcohol liquid is supplied; An alcohol liquid supply pipe for supplying alcohol liquid into the second body; And a second steam supply pipe for supplying the alcohol vapor generated in the second body to the dryer. The method of claim 3, The second steam generator further comprises an injection nozzle coupled to the front end of the alcohol liquid supply pipe connected to the second body, And the alcohol liquid is supplied into the second body in a mist state through the injection nozzle. The method of claim 4, wherein The alcohol liquid supply pipe is connected to the first body of the first steam generator, The steam supply unit further includes a second gas supply pipe for supplying a second gas to the upper portion of the alcohol liquid in the first body, And the alcohol liquid filled in the first body by the pressurization of the second gas flows into the second body through the alcohol liquid supply pipe. The method of claim 4, wherein And a carrier gas supply pipe for supplying a carrier gas for transporting the alcohol vapor generated in the second body to the dryer. The method according to any one of claims 3 to 6, When the process of drying the substrate using the Marangoni effect in the dryer is performed, the alcohol vapor generated in the first body is supplied to the dryer, The alcohol vapor generated in the second body is supplied to the dryer when the process of drying the substrate is performed by directly injecting alcohol vapor onto the substrate and replacing the liquid attached on the substrate with alcohol vapor. Drying apparatus, characterized in that. A dryer for providing a space in which the substrate is accommodated and drying the wafer; A first steam generator for supplying a low concentration of alcohol vapor to the dryer; Including a second steam generator for supplying a high concentration of alcohol vapor to the dryer, And the first steam generator generates alcohol vapor by supplying gas into the alcohol liquid, and the second steam generator generates alcohol vapor by heating the alcohol liquid in a mist state. The method of claim 8, The apparatus controls the first steam generator and the second steam generator to supply alcohol vapor to the dryer by any one selected from the first steam generator and the second steam generator according to the process conditions in the dryer. Include more, The controller, When the process of drying the substrate using the Marangoni effect in the dryer is performed, the alcohol vapor generated in the first steam generator is supplied to the dryer, and the alcohol vapor is directly sprayed onto the substrate in the dryer to And the alcohol vapor generated in the second steam generator is supplied to the dryer when the process of drying the substrate is performed by substituting the liquid vapor deposited on the substrate with alcohol vapor. The method of claim 9, The first steam generator, A first body filled with alcohol liquid; A first gas supply pipe for supplying a first gas into the alcohol liquid filled in the first body; A first steam supply pipe for supplying the alcohol vapor generated in the first body to the dryer, The second steam generator, A second body heated by a heater; An alcohol liquid supply pipe configured to supply an alcohol liquid filled in the first body to the second body, and an end injection nozzle coupled to supply the alcohol liquid to the second body in a mist state; A second gas supply pipe for supplying a second gas into the first body so as to pressurize the alcohol liquid in the first body; And a second steam supply pipe for supplying the alcohol vapor generated in the second body to the dryer.

Images