Ultraviolet and ozone clean system and method thereof

Abstract

A cleaning apparatus for cleaning a substrate includes a lamp for emitting ultraviolet radiation in an irradiated area; a housing housing the lamp; a water conduit spaced below the housing, the water conduit having a water inlet for receiving a supply of ozonated water and a water outlet for discharging ozonated water irradiated by the lamp into a substrate processing area below the water conduit, and defining a water flow path between the water inlet and the water outlet extending in the irradiated area; an upper reflector extending along and above the lamp; and a lower reflector extending along and below the water conduit, wherein the upper and lower reflectors at least partially define the irradiated area and reflect ultraviolet radiation toward the water flow path, and wherein the lower reflector shields the substrate from ultraviolet radiation emitted by the lamp.

Description

Technical Field

[0001] The embodiments disclosed herein generally relate to cleaning systems, and more specifically, to ultraviolet and ozone cleaning systems. Prior Technology

[0002] Substrates used in the semiconductor manufacturing industry are often cleaned to remove unwanted materials, such as contaminants or other unwanted particles generated on them during processing. Substrates may include semiconductor wafers, chamber components, photomasks, or the like.

[0003] Contaminants can be removed by rinsing the substrate with ozonated water irradiated with ultraviolet light. This water can be irradiated by an ultraviolet radiation source emitting ultraviolet radiation. However, the inventors have observed that some ultraviolet ozonated water cleaning elements and methods expose the substrate to the emitted ultraviolet radiation, which may unintentionally cause the removal or alteration of additional material beyond the contaminants to be cleaned. The removal or alteration of additional material can cause defects in the substrate.

[0004] Therefore, the inventors have provided an improved cleaning apparatus and method for cleaning substrates. Summary of the Invention

[0005] Embodiments of apparatus and methods for cleaning a substrate are provided herein. In some embodiments, an apparatus for cleaning a substrate includes a lamp configured to emit ultraviolet radiation in an irradiation area; a housing housing the lamp, the housing defining a cooling chamber surrounding the lamp; a water diverter spaced below the housing, the water diverter having a water inlet for receiving a supply of ozonated water and a water outlet for discharging ozonated water irradiated by the lamp into a substrate processing area below the water diverter, and defining a water flow path between the water inlet and the water outlet extending in the irradiation area; an upper reflector extending along and above the lamp within the cooling chamber of the housing; and a lower reflector extending along and below the water diverter, wherein the upper reflector and the lower reflector are configured to at least partially define the irradiation area and reflect the ultraviolet radiation emitted by the lamp toward the water flow path, and wherein the lower reflector is configured to shield the substrate from the ultraviolet radiation emitted by the lamp.

[0006] In some embodiments, an apparatus for cleaning a substrate includes a lamp configured to emit ultraviolet radiation in an irradiation area; a housing housing the lamp and defining a cooling chamber surrounding the lamp; a water guide spaced below the housing, the water guide having a water inlet for receiving a supply of ozonated water and a water outlet for discharging ozonated water irradiated by the lamp into a substrate processing area below the water guide, and defining a water flow path between the water inlet and the water outlet extending in the irradiation area; and an upper reflector within the cooling chamber of the housing. The device includes an upper reflector extending above the lamp and a lower reflector extending along and below the water guide, wherein the upper and lower reflectors are configured to at least partially define the irradiation area and reflect ultraviolet radiation emitted by the lamp toward the water flow path, and wherein the lower reflector is configured to shield the substrate from ultraviolet radiation emitted by the lamp; and a substrate support for supporting the substrate below the lower reflector in the substrate processing area, the substrate support being configured to rotate the substrate, wherein the cleaning device is configured to translate horizontally while flowing ultraviolet-irradiated ozonated water into the substrate processing area.

[0007] In some embodiments, a method for cleaning a substrate includes flowing ultraviolet-irradiated ozonated water onto the substrate while shielding the substrate from ultraviolet radiation.

[0008] Other and further embodiments of this disclosure are described below. Simple Explanation of the Diagram

[0009] The embodiments of this disclosure, which have been briefly summarized above and discussed in more detail below, can be understood by referring to the illustrated embodiments of this disclosure depicted in the accompanying drawings. However, the accompanying drawings only illustrate general embodiments of this disclosure and should therefore not be considered as limiting the scope, as other embodiments with equivalent effects are permissible with respect to this disclosure.

[0010] Figure 1, according to at least some embodiments of the present disclosure, depicts a schematic view of a multi-chamber treatment tool having a cleaning chamber.

[0011] Figure 2 depicts a schematic view of the cleaning device in the cleaning chamber of the multi-chamber treatment tool depicted in Figure 1.

[0012] Figure 3 depicts a cleaning process utilizing the cleaning apparatus depicted in Figure 2, according to at least some embodiments of this disclosure.

[0013] To facilitate understanding, the same element symbols have been used as much as possible to represent the same elements in the common symbols. The symbols are not drawn to scale and have been simplified for clarity. Elements and features of one embodiment may be beneficially incorporated into other embodiments without further explanation. Implementation

[0014] This document provides an embodiment of a cleaning chamber for cleaning a substrate. The cleaning chamber is configured to clean the substrate to remove unwanted particles or residues after the substrate has undergone wet or dry cleaning. The substrate may be, for example, a semiconductor wafer, a photomask, or the like. In the example of a photomask, photoresist may be left on the substrate. Flowing ultraviolet-irradiated ozonated water over the photoresist causes the photoresist to separate from the photomask. The separated residues and water can then be removed from the interior space of the cleaning chamber.

[0015] Figure 1, according to at least some embodiments of this disclosure, depicts a schematic view of a multi-chamber processing tool (tool) 100 having one or more wet cleaning chambers 130 (three are shown in Figure 1). The tool 100 described below is shown in an exemplary configuration, but other configurations may also be used. The tool 100 generally includes a fab interface 102, a transfer chamber 106 coupled to the fab interface 102, and a plurality of processing chambers 105, including the wet cleaning chambers 130 coupled to the transfer chamber 106. The fab interface 102 includes a plurality of loading ports 104 for receiving one or more substrates 112. The one or more substrates 112 may be semiconductor wafers, carrier substrates, photomasks, or the like. In some embodiments, the plurality of loading ports 104 are arranged along a common side of the fab interface 102. The factory interface robotic arm 110 may be arranged in the internal space 108 of the factory interface 102 to shuttle or transfer one or more substrates 112 from a plurality of loading ports 104 to a transfer chamber 106. The factory interface robotic arm 110 may be configured to rotate within the internal space 108, move laterally within the internal space 108, or both.

[0016] A transfer chamber 106 is coupled to a factory interface 102 and, in some embodiments, is positioned on the side of the factory interface 102 relative to a plurality of loading ports 104. The transfer chamber 106 includes a transfer robotic arm 116 disposed therein for traversing one or more substrates 112 received from the factory interface robotic arm 110 to one or more processing chambers 105 coupled to the transfer chamber. The transfer robotic arm 116 may be configured for rotational motion, lateral motion, or both. For example, lateral motion may be accomplished via rails on the base plate of the transfer chamber 106 or via wheels or tracks beneath the transfer robotic arm 116. Arms 122 of the transfer robotic arm 116 may expand and retract to move one or more substrates 112 into and out of the respective chambers of the plurality of processing chambers 105.

[0017] In some embodiments, the transfer robot arm 116 is configured to directly receive one or more substrates 112 from the factory interface robot arm 110. In some embodiments, the transfer robot arm 116 is configured to indirectly receive one or more substrates 112 from the factory interface robot arm 110. For example, in some embodiments, one of the factory interface 102 or the transfer chamber 106 includes a buffer 120 configured to hold one or more substrates 112. The transfer robot arm 116 may be configured to transfer one or more substrates 112 to the buffer 120, and the transfer robot arm 116 may be configured to transfer one or more substrates 112 from the buffer 120 to a plurality of processing chambers 105 and back from the plurality of processing chambers 105 to the buffer 120.

[0018] The transfer chamber 106 may have one or more environmental controls. For example, the airflow opening in the transfer chamber 106 may include a filter to filter the airflow entering the transfer chamber 106. Other environmental controls may include one or more of the following: humidity control, static control, temperature control, or pressure control.

[0019] One or more processing chambers 105 may be orthogonally coupled to transfer chamber 106, or angularly coupled relative to transfer chamber 106. The plurality of processing chambers 105 may be hermetically engaged with transfer chamber 106. Transfer chamber 106 operates substantially at atmospheric pressure, but may be configured to operate under vacuum pressure. The plurality of processing chambers 105 are configured to perform one or more processing steps on one or more substrates 112 processed in tool 100. For example, the plurality of processing chambers 105 may include one or more wet cleaning chambers 130 (three shown in Figure 1) configured to clean one or more substrates 112 with a liquid (e.g., water). The plurality of processing chambers 105 may include one or more dry cleaning chambers 140 (two shown in Figure 1) configured to perform dry cleaning processes on one or more substrates 112, for example, through plasma etching or plasma ashing processes. One or more processing chambers 105 include at least one baking chamber, for example, baking chamber 150, configured to heat one or more substrates to remove residues or smog remaining after wet or dry cleaning processes. In some embodiments, one or more wet cleaning chambers 130 are arranged on the side of a transfer chamber 106, different from one or more dry cleaning chambers 140.

[0020] Figure 2 is a schematic view of a cleaning device 200 mounted in the wet cleaning chamber 130 of the multi-chamber processing tool 100 of Figure 1. In some embodiments, the wet cleaning chamber 130 may form part of the cleaning device 200. In Figure 2, the cleaning device 200 is shown for cleaning substrate 112. Although the above illustration is related to the connection of a specific wet cleaning chamber 130 in the multi-chamber processing tool 100, the cleaning device 200 may be mounted in wet cleaning chambers with other configurations, and may be used in processing tools with other configurations, including as a stand-alone tool not coupled to the multi-chamber processing tool.

[0021] The cleaning device 200 includes a lamp 202 configured to emit ultraviolet radiation above and below the lamp in an irradiation area 204. The lamp 202 may be a low-pressure mercury ultraviolet lamp. The lamp 202 may operate at approximately 30 to 150 watts and emits ultraviolet radiation with a spectrum defined by peak amplitude between 240 nanometers and 310 nanometers. In some embodiments, the lamp emits ultraviolet radiation with a primary ultraviolet emission at approximately 254 nanometers.

[0022] The cleaning device 200 also includes a housing 206 housing a lamp 202. The housing 206 defines a cooling chamber 208 surrounding the lamp 202. In the embodiment shown in Figure 2, the housing 206 may include an upper cover 206a and a lower cover 206b, for example, sealed together with an O-ring 206c. The upper cover 206a may be formed from polytetrafluoroethylene (PTFE), and the lower cover 206b may be formed from quartz, allowing transmission of ultraviolet radiation emitted by the lamp 202. The housing 206 may have an inlet 206d and an outlet 206e. As shown in the embodiment of Figure 2, the inlet 206d and outlet 206e may be formed in the upper cover 206a. The inlet 206d may be fluidly coupled to a supply of a cooling fluid, such as dry, cold air. The outlet 206e may be fluidly coupled to a cooling fluid outlet. Inlet 206d and outlet 206e are in fluid communication with a cooling chamber 208 configured to route cooling fluid between inlet 206d and outlet 206e on lamp 202. The flow of cooling fluid on lamp 202 cools lamp 202 to control the temperature of lamp 202.

[0023] The temperature of lamp 202 can affect the peak amplitude of the emission spectrum emitted by lamp 202. For example, a lower temperature can reduce the peak amplitude. In an embodiment, cleaning device 200 may include ultraviolet monitor 203 to monitor the peak amplitude of the emission spectrum of lamp 202, which can be used as feedback to adjust the temperature of lamp 202, i.e., by adjusting parameters of the cooling fluid passing through cooling chamber 208, such as cooling fluid flow rate and cooling fluid inlet temperature. As shown in Figure 2, ultraviolet monitor 203 may be connected to housing 206.

[0024] The cleaning device 200 also includes a water conduit 210 spaced below the housing 206. The water conduit 210 has a water inlet 212 for receiving a supply of ozonated water 214 and a water outlet 216 for discharging ozonated water irradiated by the lamp 202 into a substrate processing area 218 below the water conduit 210. The water conduit 210 defines a water flow path 220 between the water inlet 212 and the water outlet 216. The water flow path 220 extends in the irradiation area 204 such that the ozonated water can be irradiated by ultraviolet radiation emitted by the lamp 202 as it passes through the irradiation area 204 toward the water outlet 216. The water conduit 210 may be formed from quartz and allows for the transmission of ultraviolet radiation emitted by the lamp 202.

[0025] Furthermore, the cleaning device 200 includes an upper reflector 222, as shown in Figure 2, which can be disposed within the cooling chamber 208 of the housing 206. The upper reflector 222 extends along and above the lamp 202. The cleaning device 200 also includes a lower reflector 224, which extends along and below the lamp 202 and below the water guide 210. The upper reflector 222 and the lower reflector 224 are configured to at least partially define the irradiation area 204 and reflect the ultraviolet radiation emitted by the lamp 202 toward the water flow path 220. The lower reflector 224 is configured to shield the substrate processing area 218 (and the substrate 112 in the substrate processing area 218) from the ultraviolet radiation emitted by the lamp 202. The upper reflector 222 and the lower reflector 224 may be formed of aluminum or an aluminum alloy, or any other suitable material that can reflect ultraviolet radiation and provide shielding for the substrate processing area 218.

[0026] The cleaning apparatus 200 may also include a substrate support 228 located in the substrate processing area 218. The substrate support 228 has a plate 228a and a rod 228b extending from the plate 228a to the wet cleaning chamber 130. The substrate support 228 is rotatably connected to the wet cleaning chamber 130. The substrate support 228 is configured to rotate around a central axis 226 extending perpendicularly through the rod 228b. As shown in Figure 2, the plate 228a is configured to support the substrate 112 in the substrate processing area 218 while ultraviolet-irradiated ozonated water flows onto the substrate 112.

[0027] The water guide 210 extends horizontally from the housing 206 to horizontally space the water outlet 216 from the housing 206. The water guide 210 extends horizontally from the housing 206 by a distance between 0.5 inches and 4 inches. Furthermore, the water outlet 216 is vertically spaced approximately 2.5 inches from the upper surface of the substrate 112.

[0028] The cleaning device 200 may include a reflector protector 230 that supports at least one of the water guide 210 and the lower reflector 224. The reflector protector 230 may have a first end 230a and a second end 230b coupled to the water guide 210. The reflector protector 230 may be connected to the wet cleaning chamber 130 via an actuator 232 (e.g., a linear actuator), the actuator 232 being configured to translate the water guide 210 and the water outlet 216 relative to the substrate support 228 within the wet cleaning chamber 130. In an embodiment, the water guide 210 may be configured to translate while rotating the substrate support 228 around a central axis 226. Translation of the water guide 210 relative to the substrate support 228 may translate the horizontal position of the water outlet 216 of the water guide 210 on the substrate processing area 218. Therefore, when the substrate 112 is supported in the substrate processing area 218 by the substrate support 228, the ultraviolet-irradiated ozonated water can be advantageously guided to different locations on the substrate 112 to be cleaned, thereby providing a more controlled (e.g., more uniform) cleaning result.

[0029] The wet cleaning chamber 130 may have a slit valve 131 operable to open and close, for example by means of a transfer robotic arm 116 (Figure 1), to allow the substrate 112 to be introduced into or removed from the interior of the wet cleaning chamber 130.

[0030] Figure 3 depicts a cleaning workflow 300 according to at least some embodiments of the disclosed invention. At 302, substrate 112 is placed on plate 228a of substrate support 228. Substrate 112 is positioned in substrate processing area 218 and vertically below water outlet 216. At 304, ozonated water supplied from ozonated water 214 flows along water flow path 220 through irradiation area 204. At 306, ultraviolet-irradiated ozonated water is discharged from water outlet 216 and falls onto substrate 112 by gravity. During the cleaning workflow 300, rod 228b of substrate support 228 can rotate around central axis 226 to rotate substrate 112 relative to water guide 210. Moreover, during the cleaning workflow 300, water guide 210 can be translated horizontally. The rotation of rod 228b can be in series with or independent of the translation of water guide 210. The ozonated water irradiated by ultraviolet light can be applied to the surface of the substrate 112 for a predetermined time, or the process can be monitored to determine the end of the cleaning process, at which time the ultraviolet lamp 202 can be turned off and the flow of the ozonated water can be stopped. The cleaned substrate 112 can then be removed from the chamber 130, and if desired, a new substrate 112 can be introduced for the cleaning process to be repeated.

[0031] Although the above-described embodiments of this disclosure are intended to lead to other and further embodiments of this disclosure without departing from its basic scope.

[0032] 100: Tools 102: Factory Interface 104: Multiple loading ports 105: Multiple processing chambers 106: Transport Chamber 108: Interior Space 110: Factory Interface Robotic Arm 112:Substrate 116: Teleportation Robotic Arm 120: Buffer 122: Arm 130: Wet cleaning chamber 131: Slit valve 140: Dry Cleaning Chamber 150: Baking Chamber 200: Cleaning device 202: Light 203: Ultraviolet Monitor 204: Irradiation area 206: Outer shell 206a: Top cover 206b: Lower cover 206c: O-ring 206d: Entrance 206e: Exports 208: Cooling Chamber 210: Water diverter 212: Water Inlet 214: Supply of ozonated water 216: Water outlet 218: Substrate processing area 220: Water Flow Path 222: Upper reflector 224: Lower reflector 226: Central axis 228: Substrate support 228a: Board 228b: Rod 230: Reflector Protector 230a: First end 230b: Second end 232: Actuator 300: Cleaning Workflow 302: Steps 304: Steps 306: Steps

[0033] Domestic storage information (please note in order of storage institution, date, and number) none Overseas storage information (please note in the order of storage country, institution, date, and number) none

Claims

1. A cleaning apparatus for cleaning a substrate, comprising: a lamp configured to emit ultraviolet radiation in an irradiation area; and a water diverter spaced below the lamp, the water diverter having a water inlet for receiving a supply of ozonated water and a water outlet for discharging ozonated water irradiated by the lamp into a substrate processing area below the water diverter, and defining a water flow path between the water inlet and the water outlet extending in the irradiation area, wherein the water outlet is offset from the irradiation area.

2. The cleaning device as claimed in claim 1 further includes an upper reflector extending along and above the lamp, wherein the upper reflector is configured to at least partially define the irradiation area and reflect ultraviolet radiation emitted by the lamp toward the water flow path.

3. The cleaning device as claimed in claim 2, wherein the upper reflector has a length equal to or greater than a length of the lamp.

4. The cleaning apparatus as claimed in claim 1, further comprising a lower reflector extending along and below the water guide, wherein the lower reflector is configured to at least partially define the irradiation area and reflect ultraviolet radiation emitted by the lamp toward the water flow path, and wherein the lower reflector is configured to shield the substrate from ultraviolet radiation emitted by the lamp.

5. The cleaning device as claimed in claim 4, wherein the lower reflector has a length equal to or greater than a length of the lamp.

6. The cleaning apparatus as claimed in claim 4 further includes a substrate support for supporting the substrate below the water outlet in the substrate processing area, wherein the lower reflector is disposed between the water outlet and the substrate support.

7. The cleaning device as claimed in claim 1, wherein the lamp operates between 30 and 150 watts.

8. The cleaning apparatus as claimed in claim 1, further comprising a substrate support for supporting the substrate below the water outlet in the substrate processing area, wherein the substrate support is configured to rotate the substrate.

9. The cleaning apparatus as claimed in claim 1, further comprising a housing housing the lamp, the housing defining a cooling chamber surrounding the lamp, wherein the housing has an inlet and an outlet in fluid communication with the cooling chamber, the cooling chamber being configured to route a cooling fluid between the inlet and the outlet of the housing and on the lamp.

10. The cleaning apparatus as claimed in claim 9, wherein the cooling fluid comprises dry, cold air.

11. The cleaning device as claimed in claim 9, wherein the housing includes an upper cover and a lower cover sealed to the upper cover, wherein the inlet and the outlet of the housing are formed in the upper cover.

12. The cleaning device as claimed in claim 11, wherein the upper cover is formed of PTFE and the lower cover is formed of quartz.

13. The cleaning device as claimed in claim 9, wherein a horizontal distance between the water outlet of the water diverter and the housing is 0.5 inches to 4 inches.

14. The cleaning apparatus as claimed in claim 1, wherein the water outlet is configured to be horizontally translated relative to the substrate processing area.

15. A method for cleaning a substrate, comprising the steps of: emitting ultraviolet radiation from a lamp in an irradiation area; receiving a supply of ozonated water at an inlet of a water conduit spaced below the lamp; and discharging the ultraviolet-irradiated ozonated water irradiated by the lamp at an outlet of the water conduit into a substrate processing area below the water conduit, the water conduit defining a water flow path between the inlet and the outlet extending in the irradiation area, wherein the outlet is offset from the irradiation area.

16. The method as described in claim 15 further comprises the step of: simultaneously discharging the ultraviolet-irradiated ozonated water and horizontally translating the outlet relative to the substrate processing area.

17. The method as described in claim 15 further comprises the step of discharging the ultraviolet-irradiated ozonated water onto a substrate in the substrate processing area.

18. The method as described in claim 17 further comprises the step of rotating the substrate while discharging the ultraviolet-irradiated ozonated water onto the substrate.

19. The method as described in claim 17 further comprises the step of: shielding the substrate from ultraviolet radiation while discharging the ultraviolet-irradiated ozonated water onto the substrate.

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