WO2009096380A1

WO2009096380A1 - Substrate cleaning apparatus, substrate cleaning method and computer storage medium

Info

Publication number: WO2009096380A1
Application number: PCT/JP2009/051251
Authority: WO
Inventors: Hisanori Sugimachi; Yoshitaka Matsuda
Original assignee: Tokyo Electron Limited
Priority date: 2008-01-31
Filing date: 2009-01-27
Publication date: 2009-08-06
Also published as: JP5002471B2; JP2009182222A

Abstract

Provided is a substrate cleaning apparatus for cleaning a rear surface of a substrate prior to exposing the substrate. The substrate cleaning apparatus is provided with a processing container having a carry in/out port for carrying in and out the substrate; a transfer mechanism, which holds an outer circumference section of the substrate and carries in and out the substrate to and from the processing container; a gas jetting nozzle which jets a gas to the rear surface of the substrate held by the transfer mechanism in the processing container; an electrostatically chargeable member which can be electrostatically charged for capturing, in theprocessing container by static electricity, adhered materials on the rear surface of the substrate held by the transfer mechanism; and an exhaust mechanism for exhausting atmosphere in the processing container. Thus, the rear surface of the substrate can be entirely cleaned efficiently prior to exposure.

Description

Substrate cleaning apparatus, substrate cleaning method, and computer storage medium

The present invention relates to a substrate cleaning apparatus, a substrate cleaning method, and a computer storage medium for cleaning the back surface of a substrate such as a semiconductor wafer before exposure.

For example, in a photolithography process in the manufacture of a semiconductor device, for example, a resist coating process in which a resist solution is applied on a semiconductor wafer (hereinafter referred to as “wafer”) to form a resist film, and a predetermined pattern is exposed on the resist film. An exposure process, a heating process for promoting a chemical reaction in the resist film after the exposure, a developing process for developing the exposed resist film, and the like are sequentially performed to form a predetermined resist pattern on the wafer.

In the exposure processing described above, the resist film is normally exposed to a predetermined pattern by placing the wafer on a mounting table and irradiating the resist film on the wafer with light. In the heat treatment after exposure, the wafer is usually placed on a hot plate and the wafer is heated by the hot plate.

Here, since various processes such as a resist coating process are performed before the wafer exposure process, deposits such as dust may adhere to the back surface of the wafer during the process or transfer of the wafer. If the above-described exposure process or heat treatment is performed with the adherent attached to the back surface of the wafer in this way, a focus error may occur due to the wafer not being properly placed on the mounting table during the exposure process, or heating may occur. During processing, the wafer may not be properly placed on the hot plate, so that the heat treatment may not be uniformly performed on the wafer surface.

Therefore, conventionally, the back surface of the wafer is cleaned before the exposure process. In this cleaning process, the spin chuck is rotated while the back surface of the wafer is adsorbed and held on the spin chuck, the cleaning liquid is sprayed on the back surface of the wafer, and the cleaning liquid is diffused on the back surface of the wafer by rotating centrifugal force to clean the back surface. (Patent Document 1).
JP 2007-134671 A

However, when the back surface of the wafer is adsorbed and held by the spin chuck and the back surface is cleaned as described above, the cleaning liquid cannot be sprayed on the portion of the back surface of the wafer held by the spin chuck, and the portion is cleaned. I couldn't. Further, when the cleaning liquid is sprayed on the back surface of the wafer, it takes time to dry the cleaning liquid on the back surface of the wafer after the cleaning process.

The present invention has been made in view of such a point, and an object thereof is to efficiently clean the entire back surface of a wafer before exposure.

In order to achieve the above object, the present invention provides a substrate cleaning apparatus for cleaning the back surface of a substrate before exposure of the substrate, comprising a processing container having a loading / unloading port for loading / unloading a substrate, and an outer peripheral portion of the substrate. A holding mechanism for carrying the substrate in and out of the processing container; a gas injection nozzle for injecting gas to the back surface of the substrate held by the conveying mechanism in the processing container; and the conveying mechanism in the processing container. And a charging member that can be charged to collect deposits on the rear surface of the held substrate by static electricity, and an exhaust mechanism that exhausts the atmosphere in the processing container.

According to the present invention, since only the outer peripheral portion of the substrate is held by the transport mechanism and the back surface of the substrate is cleaned, the entire back surface of the substrate can be cleaned. Further, since the gas can be ejected from the gas ejection nozzle to the back surface of the substrate, deposits on the back surface of the substrate can be removed from the back surface by physical force due to the gas ejection. Since the charging member can be charged at the same time as the gas injection, the adhering material on the back surface of the substrate held by the transport mechanism is sucked and collected on the surface of the charging member by the static electricity of the charged charging member. be able to. That is, since the deposit on the back surface of the substrate can be removed by both the gas injection from the gas injection nozzle and the static electricity of the charging member, the back surface of the substrate can be cleaned with a high cleaning effect. In addition, since it is not necessary to dry the cleaning liquid as in the prior art, the cleaning processing time can be shortened and the cleaning processing can be performed efficiently. Furthermore, since the atmosphere in the processing container can be exhausted by the exhaust mechanism, even if the deposit on the back surface of the substrate floats in the processing container, the deposit can be prevented from reattaching to the substrate. .

According to another aspect of the present invention, there is provided a substrate cleaning method for cleaning the back surface of a substrate before exposure of the substrate, wherein the substrate is moved into a processing container by a transport mechanism that holds the outer periphery of the substrate and transports the substrate. A carry-in step for carrying in the gas, a gas injection step for injecting gas to the back surface of the substrate held by the transfer mechanism in the processing container by a gas injection nozzle, and a substrate held by the transfer mechanism in the processing vessel During the process of collecting the deposit on the back surface of the charging member due to static electricity of the charged charging member, the gas jetting step, and the deposit collecting step, the atmosphere in the processing container And an unloading step of unloading the substrate out of the processing container by the transport mechanism.

According to another aspect of the present invention, a readable computer storage medium storing a program that operates on a computer of a control unit that controls the substrate cleaning apparatus so that the substrate cleaning method is executed by the substrate cleaning apparatus. Is provided.

According to the present invention, the entire back surface of the substrate can be efficiently cleaned in a short time with a high cleaning ability.

It is a top view which shows the outline of a structure of the coating and developing treatment system carrying the washing | cleaning apparatus concerning this Embodiment. It is a front view of a coating and developing treatment system. It is a rear view of a coating and developing treatment system. It is a longitudinal cross-sectional view which shows the outline of a structure of a washing | cleaning apparatus. It is a cross-sectional view which shows the outline of a structure of a washing | cleaning apparatus. It is explanatory drawing which shows the cleaning process of the back surface of a wafer, (a) shows a mode that a wafer is carried in in a processing container, (b) shows a mode that the back surface of a wafer is cleaned, (c) processes a wafer. The state of carrying out the container is shown, and (d) shows the state of exhausting the atmosphere in the processing container. It is a cross-sectional view which shows the outline of a structure of the washing | cleaning apparatus concerning other embodiment. It is explanatory drawing which shows the cleaning process of the back surface of a wafer, (a) shows a mode that the back surface of the wafer which is conveying the wafer in the carrying-in direction is shown, (b) is the back surface of the wafer which is conveying the wafer in the carrying-out direction It shows how to wash. It is a cross-sectional view which shows the outline of a structure of the washing | cleaning apparatus concerning other embodiment. It is explanatory drawing which shows the cleaning process of the back surface of a wafer, (a) shows a mode that the back surface of a wafer is cleaned, (b) shows a mode that a wafer is carried out of a processing container, (c) is in a processing container. It shows how the atmosphere is exhausted. It is a cross-sectional view which shows the outline of a structure of the washing | cleaning apparatus concerning other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coating | development processing system 101 Conveyance mechanism 103 Cleaning apparatus 110 Processing container 111 Carry-in / out port 120 Conveyance arm 130 Charging member 131 Temperature adjustment mechanism 132 Charging mechanism 140 Gas injection nozzle 142 Gas supply source 143 Ionizer 144 Pressure adjustment mechanism 145 Temperature adjustment mechanism 150 Exhaust Port 151 Exhaust path 152 Pump 160 Inspection mechanism 200 Control unit 210 Transport mechanism control unit 211 Height control unit 212 Transport speed control unit 220 Charging member control unit 221 Temperature control unit 222 Polarity setting unit 223 Charge amount control unit 230 Gas injection nozzle control Unit 240 exhaust mechanism control unit 300 charging member 310 collection substrate 320 through-hole S deposit W wafer

Hereinafter, preferred embodiments of the present invention will be described. FIG. 1 is a plan view showing an outline of the configuration of a coating and developing treatment system 1 equipped with a wafer back surface cleaning device according to the present embodiment, and FIG. 2 is a front view of the coating and developing treatment system 1. FIG. 3 is a rear view of the coating and developing treatment system 1.

As shown in FIG. 1, the coating and developing treatment system 1 is a cassette that carries, for example, 25 wafers W from the outside to the coating and developing treatment system 1 in a cassette unit, and carries a wafer W into and out of the cassette C. A station 2, a processing station 3 in which a plurality of various processing apparatuses for performing predetermined processing in a single wafer type in a photolithography process are arranged in multiple stages, and an exposure apparatus provided adjacent to the processing station 3 4 and the interface station 5 that transfers the wafer W to and from the unit 4.

The cassette station 2 is provided with a cassette mounting table 6. The cassette mounting table 6 can mount a plurality of cassettes C in a row in the X direction (vertical direction in FIG. 1). The cassette station 2 is provided with a transfer arm 8 that can move in the X direction on the transfer path 7. The transfer arm 8 is also movable in the wafer arrangement direction (Z direction; vertical direction) of the wafers W accommodated in the cassette C, and selectively with respect to the wafers W in each cassette C arranged in the X direction. Accessible.

The transfer arm 8 is rotatable in the θ direction around the Z axis, and is connected to a temperature adjusting device 60 belonging to a third processing device group G3 on the processing station 3 side, which will be described later, and a transition device 61 for transferring the wafer W. Also accessible.

The processing station 3 adjacent to the cassette station 2 includes, for example, five processing device groups G1 to G5 in which a plurality of processing devices are arranged in multiple stages. A first processing device group G1 and a second processing device group G2 are arranged in this order from the cassette station 2 side on the X direction negative direction (downward direction in FIG. 1) side of the processing station 3. A third processing device group G3, a fourth processing device group G4, and a fifth processing device group G5 are sequentially arranged from the cassette station 2 side on the X direction positive direction (upward direction in FIG. 1) side of the processing station 3. Has been placed. A first transfer device A1 is provided between the third processing device group G3 and the fourth processing device group G4, and the wafer W is supported and transferred inside the first transfer device A1. A first transfer arm 10 is provided. The first transfer arm 10 can selectively access each processing apparatus in the first processing apparatus group G1, the third processing apparatus group G3, and the fourth processing apparatus group G4 to transfer the wafer W. A second transfer device A2 is provided between the fourth processing device group G4 and the fifth processing device group G5, and the wafer W is supported and transferred inside the second transfer device A2. A second transfer arm 11 is provided. The second transfer arm 11 can selectively access each processing apparatus in the second processing apparatus group G2, the fourth processing apparatus group G4, and the fifth processing apparatus group G5 to transfer the wafer W.

As shown in FIG. 2, in the first processing apparatus group G1, a liquid processing apparatus that supplies a predetermined liquid to the wafer W and performs processing, for example, a resist coating apparatus 20 that applies a resist solution as a coating liquid to the wafer W. , 21, 22,

bottom coating devices

23, 24 for forming an antireflection film for preventing reflection of light during the exposure process are stacked in five stages in order from the bottom. In the second processing unit group G2, liquid processing units, for example, development processing units 30 to 34 for supplying a developing solution to the wafer W and performing development processing are stacked in five stages in order from the bottom. In addition,

chemical chambers

40 and 41 for supplying various processing liquids to the liquid processing apparatuses in the processing apparatus groups G1 and G2 are provided at the bottom of the first processing apparatus group G1 and the second processing apparatus group G2. Each is provided.

As shown in FIG. 3, the third processing unit group G3 includes a temperature control unit 60, a transition unit 61, high-precision temperature control units 62 to 64 that control the temperature of the wafer W under high-precision temperature control, and the wafer W. High temperature heat treatment apparatuses 65 to 68 for heat treatment at a high temperature are stacked in nine stages in order from the bottom.

The fourth processing unit group G4 includes, for example, a high-accuracy temperature control unit 70, pre-baking units 71 to 74 that heat-treat the resist-coated wafer W, and a post-baking unit 75 that heat-processes the developed wafer W. 79 are stacked in 10 steps from the bottom.

In the fifth processing apparatus group G5, a plurality of heat processing apparatuses for heat-treating the wafer W, for example, high-accuracy temperature control apparatuses 80 to 83 and post-exposure baking apparatuses 84 to 89 are stacked in 10 stages in order from the bottom.

As shown in FIG. 1, a plurality of processing devices are arranged on the positive side in the X direction of the first transfer device A1, and for example, an adhesion device 90 for hydrophobizing the wafer W as shown in FIG. 91, and

heating devices

92 and 93 for heating the wafer W are stacked in four stages in order from the bottom. As shown in FIG. 1, a peripheral exposure device 94 that selectively exposes only the edge portion of the wafer W, for example, is disposed on the positive side in the X direction of the second transfer device A2.

In the interface station 5, for example, as shown in FIG. 1, a transfer mechanism 101 that moves on a transfer path 100 extending in the X direction, a buffer cassette 102, and a cleaning apparatus for the back surface of the wafer W according to the present embodiment 103 is provided. The transport mechanism 101 can move in the Z direction and can also rotate in the θ direction, and with respect to the exposure apparatus 4 adjacent to the interface station 5, the buffer cassette 102, the cleaning apparatus 103, and the fifth processing apparatus group G5. The wafer W can be transferred by accessing.

Next, the configuration of the above-described cleaning apparatus 103 will be described. FIG. 4 is a longitudinal sectional view showing an outline of the configuration of the cleaning apparatus 103, and FIG. 5 is a transverse sectional view showing an outline of the configuration of the cleaning apparatus 103.

The cleaning apparatus 103 has a processing container 110 as shown in FIG. A loading / unloading port 111 for loading / unloading the wafer W held by the transfer mechanism 101 is formed on one side surface of the processing container 110, and an opening / closing shutter 112 is provided at the loading / unloading port 111.

The transfer mechanism 101 has a transfer arm 120 that holds the outer periphery of the wafer W as shown in FIG. The transfer arm 120 includes a frame portion 121 configured in a 3/4 annular shape to support the outer peripheral portion of the wafer W, and an arm portion that is formed integrally with the frame portion 121 and supports the frame portion 121. 122. The frame portion 121 is provided with, for example, three support portions 123 that directly support the outer peripheral portion of the wafer W. The support portions 123 are provided at equal intervals on the inner circumference of the frame portion 121 and project inside the frame portion 121.

As shown in FIG. 4, a base 124 that supports the transfer arm 120 is provided on the lower surface side of the transfer arm 120. The base 124 has a built-in motor (not shown), for example, and can move the transfer arm 120 in the horizontal direction. A shaft 125 that supports the base 124 is provided on the lower surface side of the base 124. A drive mechanism 126 incorporating a motor (not shown), for example, is further provided on the lower surface side of the shaft 125, and the transport arm 120 can be moved up and down in the vertical direction (Z direction in FIG. 4) by this drive mechanism 126. Yes and can rotate.

The transport mechanism 101 is connected to a transport mechanism control unit 210 of the control unit 200 as shown in FIG. A height control unit 211 is provided in the transport mechanism control unit 210, and the height control unit 211 controls the drive mechanism 126 so that the height of the transport arm 120 is controlled to an appropriate height. In addition, a transport speed control unit 212 is provided in the transport mechanism control unit 210, and the transport arm 120 is controlled to an appropriate transport speed by controlling the base 124 by the transport speed control unit 212. Then, the wafer W held by the transfer arm 120 is transferred by the transfer mechanism 101 in the horizontal direction (X direction in FIG. 4) in the processing container 110.

A charging member 130 that can be charged to a predetermined polarity is provided near the center of the processing container 110 as shown in FIG. The charging member 130 has, for example, a flat plate shape, and the width in the direction perpendicular to the conveyance direction of the wafer W (the Y direction in FIG. 5) is longer than the diameter of the wafer W. Further, as shown in FIG. 4, the charging member 130 is provided below the back surface of the wafer W held by the transfer arm 120 in the processing container 110. For example, an aluminum material is used for the charging member 130.

On the lower surface side of the charging member 130, a temperature adjusting mechanism 131 for adjusting the temperature of the charging member 130 is provided as shown in FIG. The charging member 130 is connected to a charging mechanism 132 that charges the charging member 130 to a predetermined polarity. For the charging mechanism 132, for example, a DC power source is used.

The temperature adjustment mechanism 131 and the charging mechanism 132 are connected to the charging member control unit 220 of the control unit 200 as shown in FIG. A temperature controller 221 is provided in the charging member controller 220, and the temperature of the charging member 130 is controlled by the temperature controller 221. The charging member 130 is controlled to be lower than the temperature of the atmosphere in the processing container 110, for example. In addition, a polarity setting unit 222 is provided in the charging member control unit 220, and the polarity of the charge charged on the charging member 130 by the polarity setting unit 222 is set to a predetermined polarity. Further, a charging amount control unit 223 is provided in the charging member control unit 220, and the charge charged to the charging member 130 by the charging amount control unit 223 is controlled to an appropriate charge amount. Then, static electricity is generated when the charging member 130 is charged, and deposits on the back surface of the wafer W held on the transfer arm 120 are collected on the surface of the charging member 130 by the static electricity.

As shown in FIG. 5, a gas injection nozzle 140 capable of injecting gas is provided in the processing container 110 on the wafer W loading direction side from the charging member 130 (X direction negative direction side from the charging member 130). It has been. The gas injection nozzle 140 extends in a direction perpendicular to the transfer direction of the wafer W (Y direction in FIG. 5). Further, as shown in FIG. 4, the gas injection nozzle 140 is provided below the back surface of the wafer W held by the transfer arm 120 in the processing container 110, and is oblique to the charging member 130 side (X direction in FIG. 4). Gas can be injected upward.

The gas injection nozzle 140 is connected to a gas supply source 142 that stores a predetermined gas, such as nitrogen gas or air, through a pipe 141 as shown in FIG. The pipe 141 is provided with an ionizer 143 for mixing the gas supplied from the gas supply source 142 with ion molecules having a polarity different from that of the charging member 130. The pipe 141 is provided with a temperature adjustment mechanism 144 for controlling the gas supplied from the gas supply source 142 to a predetermined temperature. Further, the pipe 141 is provided with a pressure adjusting mechanism 145 that pumps the gas at a predetermined pressure in order to set the gas injected from the gas injection nozzle 140 to a predetermined pressure. The ionizer 143, the temperature adjustment mechanism 144, and the pressure adjustment mechanism 145 are provided in this order from the gas supply source 142.

The ionizer 143, the temperature adjustment mechanism 144, and the pressure adjustment mechanism 145 are connected to the gas injection nozzle controller 230 of the controller 200 as shown in FIG. The gas injection nozzle control unit 230 performs control so that ion molecules mixed with the gas by the ionizer 143 are charged to a polarity different from that of the charging member 130. Further, the gas injection nozzle control unit 230 controls the gas to an appropriate temperature by the temperature adjustment mechanism 144, for example, to control the temperature higher than the temperature of the charging member 130. Further, the gas injection nozzle control unit 230 controls the gas so as to have an appropriate pressure by the pressure adjusting mechanism 145. Then, a predetermined gas is injected from the gas injection nozzle 140 onto the back surface of the wafer W held on the air transfer arm 120.

As shown in FIG. 4, an exhaust port 150 for exhausting the atmosphere in the processing container 110 is formed on the bottom surface of the processing container 110. The exhaust port 150 is formed around the charging member 130. An exhaust path 151 is connected to the exhaust port 150, and a pump 152 that evacuates the atmosphere in the processing container 110 is connected to the exhaust path 151. The exhaust port 150, the exhaust path 151, and the pump 152 constitute an exhaust mechanism.

The pump 152 is connected to the exhaust mechanism control unit 240 of the control unit 200 as shown in FIG. The exhaust mechanism control unit 240 controls timing for operating the pump 152 and the like. For example, the pump 152 is controlled to operate while the back surface of the wafer W is being cleaned by the charging member 130 and the gas injection nozzle 140.

In the processing container 110, an inspection mechanism 160 for inspecting the deposit on the back surface of the wafer W is provided on the inner surface on the loading / unloading exit 111 side as shown in FIG. The gas inspection mechanism 160 extends in a direction perpendicular to the transfer direction of the wafer W (Y direction in FIG. 5). Further, the inspection mechanism 160 is provided below the back surface of the wafer W held by the transfer arm 120 in the processing container 110 as shown in FIG. The inspection mechanism 160 is a line sensor, for example, and can inspect the deposits remaining on the back surface of the wafer W after cleaning the back surface of the wafer W.

The inspection result in the inspection mechanism 160 is transmitted to the control unit 200 as shown in FIG. In the control unit 200, based on the inspection result, for example, in the cleaning condition of the wafer W to be loaded next, that is, in the transfer mechanism control unit 210, the charging member control unit 220, the gas injection nozzle control unit 230, and the exhaust mechanism control unit 240. Each control condition is determined.

The control unit 200 described above is configured by, for example, a computer having a CPU, a memory, and the like. For example, by executing a program stored in the memory, the cleaning of the back surface of the wafer W in the cleaning apparatus 103 can be realized. Various programs for realizing the cleaning of the back surface of the wafer W in the cleaning apparatus 103 are, for example, a computer-readable hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnet optical desk (MO), What is stored in a storage medium such as a memory card and installed in the control unit 200 from the storage medium is used.

Next, cleaning of the back surface of the wafer W performed by the cleaning apparatus 103 configured as described above will be described together with a wafer processing process performed by the entire coating and developing processing system 1.

First, one wafer W is taken out from the cassette C on the cassette mounting table 6 by the transfer arm 8 and transferred to the temperature control device 60 of the third processing unit group G3. The wafer W transferred to the temperature adjusting device 60 is adjusted to a predetermined temperature, and then transferred to the bottom coating device 23 by the first transfer arm 10 to form an antireflection film. The wafer W on which the antireflection film is formed is sequentially transferred by the first transfer arm 10 to the heating device 92, the high temperature heat treatment device 65, and the high precision temperature adjustment device 70, and is subjected to predetermined processing in each device. Thereafter, the wafer W is transferred to the resist coating apparatus 20.

When a resist film is formed on the wafer W in the resist coating apparatus 20, the wafer W is transferred to the pre-baking apparatus 71 by the first transfer arm 10, and then the peripheral exposure apparatus 94 and the high exposure apparatus 94 are moved by the second transfer arm 11. It is sequentially conveyed to the precision temperature control device 83, and predetermined processing is performed in each device. Thus, deposits such as dust adhere to the back surface of the wafer W that has been subjected to various processes such as resist coating and heat treatment when the wafer W is held or while the wafer W is being transferred. In order to clean the back surface of the wafer W, the wafer W is transferred to the cleaning device 103 by the transfer mechanism 101 of the interface station 5, and a cleaning process described later is performed.

Thereafter, the wafer is transferred to the exposure apparatus 4 by the transfer mechanism 101 of the interface station 5, and a predetermined pattern is exposed on the resist film on the wafer W. The wafer W that has been subjected to the exposure process is transferred to the post-exposure baking apparatus 84 by the transfer mechanism 101 and subjected to a predetermined process.

When the heat treatment in the post-exposure baking apparatus 84 is completed, the wafer W is transferred to the high-accuracy temperature adjustment apparatus 81 by the second transfer arm 11 and the temperature is adjusted, and then transferred to the development processing apparatus 30 and developed on the wafer W. Is applied to form a pattern on the resist film. Thereafter, the wafer W is transferred to the post-baking device 75 by the second transfer arm 11 and subjected to heat treatment, and then transferred to the high-accuracy temperature adjusting device 63 to adjust the temperature. Then, the wafer W is transferred to the transition device 61 by the first transfer arm 10 and returned to the cassette C by the transfer arm 8 to complete a series of photolithography steps.

Next, the cleaning process for the back surface of the wafer W in the cleaning apparatus 103 will be described.

First, the opening / closing shutter 112 is opened, and the wafer W is loaded into the processing container 110 from the loading / unloading port 111 while being held by the transfer arm 120 (FIG. 6A). Then, the wafer W is transported in the carry-in direction (X direction negative direction in FIG. 6).

When the wafer W is conveyed above the charging member 130, the charging member 130 is charged to a predetermined polarity, for example, an anode, and gas is injected from the gas injection nozzle 140 toward the back surface of the wafer W being transferred. Then, the deposit S that has adhered to the back surface of the wafer W is physically peeled off from the back surface of the wafer W by gas injection from the gas injection nozzle 140 and is attracted by the static electricity of the charging member 130. Collected on the surface. At this time, since the gas ejected from the gas ejection nozzle 140 includes a polarity different from the polarity of the charging member 130, for example, ionic molecules of the cathode, the ionic molecules adhere around the deposit S, and the deposit S Charges the cathode. Then, the deposit S is easily collected by the charging member 130. While the back surface of the wafer W is being cleaned by the charging member 130 and the gas injection nozzle 140 in this way, the pump 152 of the exhaust mechanism is operated. Then, even when the deposit S is peeled off from the back surface of the wafer W and floated in the processing container 110, the atmosphere in the processing container 110 containing the deposit S can be exhausted, and the deposit S is re-applied to the wafer W. Adhesion can be prevented (FIG. 6B).

When the entire back surface of the wafer W is cleaned by the static electricity of the charging member 130 and the gas jet from the gas jet nozzle 140, the wafer W is transported in the unloading direction (X direction positive direction in FIG. 6). During the transfer of the wafer W, the pump 152 of the exhaust mechanism is kept operating. Then, when the wafer W passes above the inspection apparatus 160, the inspection apparatus 160 is operated to inspect whether there is a deposit S remaining on the back surface of the wafer W. Thereafter, the wafer W is carried out of the processing container 110 (FIG. 6C). The inspection result of the inspection apparatus 160 is transmitted to the control unit 200 and the control unit 200, and the control unit 200 determines, for example, a cleaning condition for the next wafer W to be loaded based on the inspection result. This series of cleaning processes is performed during the transfer of the wafer W while the wafer W is held by the transfer arm 120.

Such a cleaning process is repeatedly performed on a predetermined number of wafers W. If it does so, since the collected matter S collected on the surface of the charging member 130 will need to be removed periodically. When removing the deposit S, first, the open / close shutter 112 is closed to seal the inside of the processing container 110. After the charging of the charging member 130 is stopped and the adsorbing force on the deposit S is weakened, the pump 152 is operated to exhaust the atmosphere in the processing container 110 together with the deposit S (FIG. 6D).

According to the above embodiment, since only the outer peripheral portion of the wafer W is held by the transfer arm 102 and the back surface of the wafer W is cleaned, the entire back surface of the wafer W can be cleaned. Further, since the gas can be ejected from the gas ejection nozzle 140 to the back surface of the wafer W, the deposit S on the back surface of the wafer W can be removed from the back surface by a physical force due to the gas ejection. Since the charging member 130 can be charged at the same time as the gas injection, the charging member 130 sucks the deposit S on the back surface of the transfer arm 102 held by the transfer arm 102 by the static electricity of the charged charging member 130. 130 can be collected on the surface. That is, since the deposit S on the back surface of the wafer W can be removed by both the gas injection from the gas injection nozzle 140 and the static electricity of the charging member 130, the back surface of the wafer W can be cleaned with a high cleaning effect. In addition, since it is not necessary to dry the cleaning liquid as in the prior art, the cleaning processing time can be shortened and the cleaning processing can be performed efficiently.

Further, since the atmosphere in the processing container 110 can be exhausted from the exhaust port 150 of the exhaust mechanism, even if the deposit S on the back surface of the wafer W floats in the processing chamber 110, the deposit S is attached to the wafer W. Reattachment can be prevented.

Further, since the gas ejected from the gas ejection nozzle 140 contains ions having a polarity different from that of the charging member 130, the deposit S is charged to a polarity different from that of the charging member 130. Then, the deposit S is easily collected by the charging member 130.

Further, the cleaning apparatus 103 can efficiently perform the cleaning process on the back surface of the wafer W and reduce the deposits S on the back surface of the wafer W before the exposure process. A focus error at the time of exposing the resist film of W can be reduced. Furthermore, in the post-exposure baking apparatus 84, the heat treatment of the wafer W after the exposure processing can be performed uniformly. Then, the line width of the resist pattern on the wafer W can be made uniform.

Further, since the spin chuck and the cleaning liquid supply system conventionally used for cleaning the wafer W are not required, the manufacturing cost of the cleaning apparatus 103 can be reduced.

Further, the temperature of the charging member 130 is controlled to be lower than the temperature of the atmosphere in the processing container 110. According to the inventors, it has been found that when the temperature of the charging member 130 is controlled in this way, the deposit S on the back surface of the wafer W is likely to adhere to the charging member 130. Moreover, since the temperature of the gas injected from the gas injection nozzle 140 is controlled to be higher than the temperature of the charging member 130, the above-described deposit S collecting effect can be further promoted.

In the above embodiment, the charging member 130 is charged with one polarity. However, as shown in FIG. 7, the charging member 300 may be divided and charged with different polarities. The charging member 300 includes divided

members

301 and 302 that are divided into two in the conveyance direction of the wafer W (X direction in FIG. 7). The dividing member 301 is charged to, for example, an anode, and the dividing member 302 is charged to, for example, a cathode. Then, the wafer W is carried into the processing container 110, and during the transfer of the wafer W, gas is injected from the gas injection nozzle 140, and for example, the divided member 301 is charged to the anode to divide the deposit S on the back surface of the wafer W. Collected on the surface of the member 301. At this time, the gas ejected from the gas ejection nozzle 140 includes negative ion molecules that are different in polarity from the split member 301 (FIG. 8A). Next, while the wafer W is transported in the unloading direction (the positive direction of the X direction in FIG. 8), gas is injected from the gas injection nozzle 140 and the split member 302 is charged to the cathode so that the back surface of the wafer W is charged. The deposit S is collected on the surface of the dividing member 302. At this time, the gas ejected from the gas ejection nozzle 140 contains ionic molecules of the anode having a polarity different from that of the dividing member 302 (FIG. 8B). In such a case, due to the nature of the deposit S, even if the deposit S cannot be collected on the charging member 300 with either polarity, the deposit S can be collected in the bipolar state during the cleaning process. The back surface of the wafer W can be cleaned efficiently.

On the charging member 130 of the above embodiment, a collection substrate 310 for collecting the deposit S may be further provided as shown in FIG. The collection substrate 310 is supported by a conductive support member 311 provided on the charging member 130. When the charging member 130 is charged, the collection substrate 310 can be charged to the same polarity. For the collection substrate 310, for example, the same material and shape as the wafer W are used. Then, the wafer W is carried into the processing container 110 and gas is injected from the gas injection nozzle 140 and the collection substrate 310 is charged via the charging member 130 to collect the deposit S on the back surface of the wafer W. It collects on the surface of the substrate 310 (FIG. 10A). After cleaning the back surface of the wafer W in this way, the wafer W is carried out of the processing container 110 (FIG. 10B). After the cleaning process is performed on a predetermined number of wafers W, when the deposit S collected on the collection substrate 310 is removed, the collection substrate 310 is moved to the processing container by the transfer arm 102. 110 is carried out (FIG. 10C). Then, the collection substrate 310 is washed outside the processing container 110. In this case, since the collection substrate 310 can be cleaned outside the processing container 100, the exhaust processing in the processing container 110 performed when cleaning the charging member 130 in the above embodiment can be omitted. it can. Therefore, since the maintenance time of the cleaning apparatus 103 can be shortened, the throughput of wafer processing can be improved.

In the above embodiment, the gas injection nozzle 140 is provided separately from the charging member 130. However, as shown in FIG. 11, the gas injection nozzle 140 is omitted, and a plurality of through holes 320 are provided in the charging member 130. Gas may be injected from the through hole 320 to the back surface of the wafer W. A gas supply source 142 is connected to the plurality of through holes 320 via the pipe 141 described above, and the pipe 141 is provided with an ionizer 143, a temperature adjustment mechanism 144, and a pressure adjustment mechanism 145. Even in such a case, the back surface of the wafer W can be cleaned by gas injection from the through hole 320 and static electricity of the charging member 130. Moreover, since the gas injection nozzle 140 becomes unnecessary, the manufacturing cost of the cleaning device 103 can be reduced, and the cleaning device 103 can be downsized.

In the above embodiment, the cleaning device 103 and the buffer cassette 102 are provided at different positions, but the cleaning device 103 may be provided below the buffer cassette 102. As a result, the area occupied by the coating and developing treatment system 1 can be reduced.

The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the idea described in the claims, and these naturally belong to the technical scope of the present invention. It is understood. The present invention is not limited to this example and can take various forms. The present invention can also be applied to a case where the substrate is another substrate such as an FPD (flat panel display) other than a wafer or a mask reticle for a photomask.

The present invention is useful when cleaning the back surface of a substrate such as a semiconductor wafer before exposure.

Claims

A substrate cleaning apparatus for cleaning the back surface of the substrate before exposure of the substrate,
A processing container having a loading / unloading port for loading and unloading a substrate;
A transport mechanism that holds the outer periphery of the substrate and carries the substrate into and out of the processing container;
A gas injection nozzle for injecting gas to the back surface of the substrate held by the transport mechanism in the processing container;
A charging member that can be charged to collect deposits on the back surface of the substrate held by the transport mechanism in the processing container by static electricity; and
And an exhaust mechanism for exhausting the atmosphere in the processing container.
The substrate processing apparatus according to claim 1,
The gas ejected from the gas ejection nozzle includes ion molecules having a polarity different from that of the charging member.
The substrate cleaning apparatus according to claim 1,
The gas injection nozzle is provided with a pressure adjustment mechanism that adjusts the injection pressure of the gas injected from the gas injection nozzle.
The substrate cleaning apparatus according to claim 1,
The gas injection nozzle is provided with a temperature adjustment mechanism that adjusts the temperature of the gas injected from the gas injection nozzle.
The substrate cleaning apparatus according to claim 1,
The charging member is provided with a temperature adjusting mechanism for adjusting the temperature of the charging member.
The substrate cleaning apparatus according to claim 1,
The charging member is provided with a charging mechanism for charging the charging member,
The charging mechanism is provided with a charge amount control unit for controlling the charge amount of the charging member.
The substrate cleaning apparatus according to claim 1,
The charging member is provided with a charging mechanism for charging the charging member,
The charging mechanism is provided with a polarity setting unit that sets the polarity of the charging member.
The substrate cleaning apparatus according to claim 1,
The charging members are divided, and each charging member can be charged to a different polarity.
A substrate cleaning method for cleaning the back surface of the substrate before exposure of the substrate,
A carrying-in process of carrying the substrate into the processing container by a transport mechanism that transports the substrate while holding the outer periphery of the substrate;
A gas injection step of injecting gas by a gas injection nozzle on the back surface of the substrate held by the transport mechanism in the processing container;
An adhering matter collecting step for collecting adhering matter on the back surface of the substrate held by the transport mechanism in the processing container by static electricity of a charged charging member;
An exhaust process for exhausting the atmosphere in the processing container by an exhaust mechanism while the gas injection process and the deposit collection process are performed;
An unloading step of unloading the substrate out of the processing container by the transfer mechanism;
Have
The substrate processing method according to claim 9,
The gas ejected from the gas ejection nozzle in the gas ejection step includes ion molecules having a polarity different from that of the charging member.
The substrate processing method according to claim 9,
In the unloading step, the deposit on the back surface of the substrate is inspected.
The substrate processing method according to claim 9,
After the unloading step, the atmosphere in the processing container is exhausted.
The substrate processing method according to claim 9,
On the charging member, a collection substrate for collecting deposits on the back surface of the substrate held by the transport mechanism is provided,
After the unloading step, the collection substrate is unloaded from the processing container.
A readable computer storage medium storing a program that operates on a computer of a control unit that controls the substrate cleaning apparatus in order to execute the substrate cleaning method by the substrate cleaning apparatus,
The substrate processing method is a substrate cleaning method for cleaning the back surface of the substrate before exposure of the substrate,
A carrying-in process of carrying the substrate into the processing container by a transport mechanism that transports the substrate while holding the outer periphery of the substrate;
A gas injection step of injecting gas by a gas injection nozzle on the back surface of the substrate held by the transport mechanism in the processing container;
An adhering matter collecting step for collecting adhering matter on the back surface of the substrate held by the transport mechanism in the processing container by static electricity of a charged charging member;
An exhaust process for exhausting the atmosphere in the processing container by an exhaust mechanism while the gas injection process and the deposit collection process are performed;
An unloading step of unloading the substrate out of the processing container by the transfer mechanism.