Atomic oxygen and ozone cleaning apparatus having a temperature control device

Abstract

The disclosed embodiments relate to an oxygen cleaning chamber with temperature control of a UV radiation generating device and a method for cleaning a substrate with atomic oxygen. The atomic oxygen cleaning chamber includes a process chamber, a cooling chamber coupled to the process chamber, and a divider hermetically separating the process chamber from the cooling chamber. An ultraviolet (UV) radiation generating device is disposed in the cooling chamber and provides UV radiation into the process chamber through the divider. A gas distribution assembly distributes ozone onto a top surface of a pedestal of the process chamber, and a coolant distribution assembly distributes cooling gas into the cooling chamber to cool the UV radiation generating device. By actively cooling the UV radiation generating device, higher intensity UV radiation is generated at a stable wavelength, i.e., without the wavelength drift typically associated with the output of high power UV radiation generating devices.

Description

Technical Field

[0001]

[0001] Embodiments of the present disclosure generally relate to an apparatus and method for cleaning a device. More specifically, embodiments of the present disclosure relate to an oxygen cleaning chamber with temperature control of a UV radiation generator, and a method for cleaning a substrate with atomic oxygen.

Background Art

[0002]

[0002] In the cleaning of semiconductor devices, it is often desirable to remove contaminants from the surface of the substrate to leave a clean surface. If cleaning is not performed, there may be contaminants that adversely affect the performance of the semiconductor device. The cleanliness of semiconductor devices and chamber components affects product yield, chamber operating time, and customer costs.

[0003]

[0003] Most substrate cleaning techniques utilize an oxygen-containing cleaning agent that is exposed to ultraviolet (UV) radiation to oxidize the surface of the substrate. Atomic oxygen has the highest reaction rate and oxidation ability compared to other oxygen-containing cleaning agents, so it can clean the surface of the substrate at a faster rate and increase throughput. However, atomic oxygen has a short lifespan and once formed, it binds to O2 and other molecules of the oxygen-containing cleaning agent. Furthermore, increasing the formation efficiency of atomic oxygen depends on the intensity of the UV radiation from the UV radiation generator. However, increasing the intensity increases the heat radiated from the UV radiation generator, leading to a shift in the radiation spectrum of the UV radiation.

[0004]

[0004] Therefore, there is a need for an improved oxygen cleaning chamber and a method for cleaning a substrate with atomic oxygen.

Summary of the Invention

[0005]

[0005] In one embodiment, an atomic oxygen cleaning chamber is provided. The atomic oxygen cleaning chamber includes a process chamber. The atomic oxygen cleaning chamber further includes a cooling chamber coupled to the process chamber and a divider that hermetically separates the process chamber from the cooling chamber. The atomic oxygen cleaning chamber further includes an ultraviolet (UV) radiation generator disposed in the cooling chamber and operable to supply UV radiation into the process chamber through the divider, and a pedestal disposed in the process chamber. The atomic oxygen cleaning chamber further includes a gas distribution assembly operable to distribute ozone onto the upper surface of the pedestal, and a coolant distribution assembly operable to distribute a cooling gas within the cooling chamber to cool the UV radiation generator.

[0006]

[0006] In another embodiment, an atomic oxygen cleaning chamber is provided. The atomic oxygen cleaning chamber includes a process chamber. The atomic oxygen cleaning chamber further includes a cooling chamber coupled to the process chamber and a divider that hermetically separates the process chamber from the cooling chamber. The atomic oxygen cleaning chamber further includes an ultraviolet (UV) radiation generator disposed in the cooling chamber and operable to supply UV radiation into the process chamber through the divider, and a pedestal disposed in the process chamber. The atomic oxygen cleaning chamber further includes a gas distribution assembly operable to distribute ozone onto the upper surface of the pedestal, and a coolant distribution assembly. The coolant distribution assembly includes a coolant gas inlet, a coolant gas outlet, a coolant gas source operable to distribute the cooling gas throughout the cooling chamber, and a coolant pump operable to send the cooling gas to the coolant gas outlet throughout the cooling chamber.

[0007]

[0007] In yet another embodiment, a method for cleaning a substrate with atomic oxygen is provided. The method for cleaning a substrate with atomic oxygen includes positioning the substrate on an upper surface of a pedestal disposed in a process chamber. The method for cleaning a substrate with atomic oxygen further includes flowing ozone into the process chamber to dispense ozone onto the substrate. The method for cleaning a substrate with atomic oxygen further includes flowing a cooling gas into a cooling chamber to maintain the temperature of a UV radiation generator below a predetermined temperature. The method for cleaning a substrate with atomic oxygen further includes supplying radiation having a wavelength from about 240 nanometers (nm) to about 310 nm from a UV radiation generator disposed in the cooling chamber to ozone disposed in the process chamber.

[0008]

[0008] To enable a more detailed understanding of the features of the present disclosure described above, the present disclosure summarized above will be described more specifically with reference to embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings merely illustrate exemplary embodiments and should not be regarded as limiting the scope of the present disclosure, and other equally effective embodiments may also be acceptable.

Brief Description of the Drawings

[0009]

Figure 1A

Figure 1B

Figure 2

Modes for Carrying Out the Invention

[0010]

[0011] For ease of understanding, wherever possible, the same reference numerals have been used to denote the same elements common to the drawings. It is contemplated that elements and features of one embodiment may be beneficially incorporated into other embodiments without further elaboration.

[0011]

[0012] Embodiments of the present disclosure generally relate to an apparatus and method for cleaning a device. More specifically, embodiments of the present disclosure relate to an oxygen cleaning chamber with temperature control of a UV radiation generator and a method for cleaning a substrate with atomic oxygen. The atomic oxygen cleaning chamber includes a process chamber. The atomic oxygen cleaning chamber further includes a cooling chamber coupled to the process chamber and a divider that hermetically separates the process chamber from the cooling chamber. The atomic oxygen cleaning chamber further includes an ultraviolet (UV) radiation generator disposed in the cooling chamber and operable to supply UV radiation into the process chamber through the divider, and a pedestal disposed in the process chamber. The atomic oxygen cleaning chamber further includes a gas distribution assembly operable to distribute ozone onto the upper surface of the pedestal, and a coolant distribution assembly operable to distribute a coolant gas within the cooling chamber to cool the UV radiation generator.

[0012]

[0013] Figures 1A and 1B are schematic cross-sectional views of an atomic oxygen cleaning chamber 100. The atomic oxygen cleaning chamber 100 is suitable for cleaning a substrate using atomic oxygen. The atomic oxygen cleaning chamber 100 of FIG. 1B includes a coolant recirculation assembly 168. The atomic oxygen cleaning chamber 100 of FIG. 1B includes all the elements of the atomic oxygen cleaning chamber 100 of FIG. 1A, with the coolant recirculation assembly 168 added. The atomic oxygen cleaning chamber 100 includes a cooling chamber 102 and a process chamber 103. The cooling chamber 102 is coupled to the process chamber 103. The cooling chamber 102 and the process chamber 103 are separated by a divider 104. The cooling chamber 102 is stacked adjacent to the process chamber 103. The divider 104 provides a seal that separates and isolates the process chamber 103 from the cooling chamber 102. The cooling chamber 102 and the process chamber 103 may be two separate bodies stacked adjacent to each other. Also, the cooling chamber 102 and the process chamber 103 may be integral. The cooling chamber 102 includes a cooling region 106. The cooling region 106 is a space defined by the cooling chamber 102 and the divider 104. The process chamber 103 includes a processing region 108. The processing region 108 is a space defined by the process chamber 103 and the divider 104.

[0013]

[0014] The processing region 108 includes a pedestal 110 for supporting a substrate 101 within the process chamber 103. The pedestal 110 is supported by a stem 112. The pedestal 110 is movably disposed within the processing region 108 by a stem 112 that extends through the process chamber 103. The stem 112 is connected to a lift system (not shown) that moves the pedestal 110 between a processing position (as shown) and a transfer position that facilitates transfer of the substrate in and out of the processing region 108 through a slit valve 114 formed through the process chamber 103. The processing position corresponds to a distance 116 from an ultraviolet (UV) radiation generating device 118 to the upper surface 120 of the pedestal 110.

[0014]

[0015] The process chamber 103 includes a gas distribution assembly 122. The gas distribution assembly 122 includes a gas inlet 124, an oxygen-containing gas source 126, an ozone (O3) generator 128, and a flow controller 130. The gas inlet 124 is disposed in the process chamber 103. The ozone generator 128 is fluidly connected to the oxygen-containing gas source 126 via a first conduit 132. The ozone generator 128 can generate ozone from the oxygen-containing gas and maintain the ozone at a desired pressure and concentration. A flow controller 130, such as a mass flow control (MFC) device, which is fluidly connected to the ozone generator 128 via a second conduit 134, controls the flow rate of ozone from the ozone generator 128. The atomic oxygen cleaning chamber 100 includes a controller 138. The controller 138 includes a central processing unit (CPU), a memory, and support circuits for the CPU. The controller 138 communicates with the flow controller 130 to control the flow rate of ozone entering the processing region 108. The controller 138 enables control of the operating parameters of the atomic oxygen cleaning chamber 100 and processes such as a method 200 for cleaning the substrate 101 with atomic oxygen.

[0015]

[0016] Ozone is flowed into the process chamber 103 from the ozone generator 128 via the gas inlet 124 and the flow controller 130. The gas inlet 124 is connected to the flow controller 130 via a third conduit 136. The ozone flow is distributed over the upper surface 120 of the pedestal 110. A gas outlet 140 is disposed in the process chamber 103. A pump 143 is coupled to the gas outlet 140 to control the pressure within the processing region 108 and exhaust by-products from the processing region 108 through the gas outlet 140 via a fourth conduit 141. The processing region 108 includes a UV intensity sensor 148 disposed therein. The UV intensity sensor 148 is operable to measure the UV intensity of the UV radiation emitted by the UV radiation generator 118.

[0016]

[0017] UV radiation from the UV radiation generator 118 can pass from the cooling region 106 through the divider 104 to the processing region 108. The divider 104 holds the heat dissipated by the UV radiation generator 118 in the cooling chamber 102 so that the temperature of the process chamber 103 can be more effectively controlled. The divider 104 is a transparent material operable to allow UV radiation to pass through. For example, the divider 104 is fused quartz, fused silica, a combination thereof, or other suitable materials.

[0017]

[0018] The UV radiation generator 118 is disposed in the cooling region 106. The UV radiation generator 118 may include one or more UV radiation sources. Each UV radiation source may be a low-pressure mercury lamp. The UV radiation generator 118 generates UV radiation. The UV radiation generator 118 may include a lamp, an LED emitter, or other UV emitter configured to emit radiation having a wavelength from about 240 nm to about 310 nm. For example, the UV radiation generator 118 emits radiation having a wavelength of about 253 nm.

[0018]

[0019] Ozone from the ozone generator 128 distributed on the surface of the substrate 101 is exposed to UV radiation from the UV radiation generator 118 and converted into oxygen gas (O2) and atomic oxygen (O). The oxygen gas and atomic oxygen oxidize inorganic materials such as hydrocarbons on the surface of the substrate 101, generating carbon dioxide (CO2) and water (H2O) as by-products. The pump 143 evacuates the by-products from the processing region 108. Atomic oxygen has the highest reaction rate and oxidation ability compared to other oxygen-containing cleaning agents, so it cleans the surface of the substrate 101 at a faster rate and improves throughput. For example, atomic oxygen can instantaneously oxidize SO2 to SO3 on the surface of the substrate 101. SO3 can be easily removed from the substrate 101 by a water-based cleaning step. SO3 can be removed by the pump 143 or in a subsequent cleaning process. When SO2 is removed by cleaning the substrate 101 with atomic oxygen, the accumulation of haze defects is slowed down. As described above, atomic oxygen has a short lifespan and once formed, it binds to O2 and other molecules. The ozone generator 128 can continuously supply ozone to the processing region 108, and the UV radiation generated by the UV radiation generator 118 converts the ozone into atomic oxygen in situ (in that place). The in-situ generation of atomic oxygen in the processing region 108 supplies a high concentration of atomic oxygen to the surface of the substrate 101. The coolant recirculation assembly 168 maintains the UV radiation generator 118 at a constant temperature to prevent drift of the emission spectrum that causes a decrease in the intensity of the UV radiation. The coolant recirculation assembly 168 improves the intensity of the UV radiation from the UV radiation generator 118 to enhance the efficiency of the atomic oxygen cleaning process. The concentration of atomic oxygen supplied to the surface of the substrate 101 is controlled by the distance 116 from the UV radiation generator 118 to the upper surface 120 of the pedestal 110.

[0019]

[0020] The cooling chamber 102 includes a reflector 150. The reflector 150 is disposed in the cooling region 106 and coupled to the cooling chamber 102. The reflector 150 is operable to reflect the UV radiation emitted by the UV radiation generator 118, whereby the UV radiation is more efficiently guided into the processing region 108 through the divider 104. In one embodiment, the reflector 150 is disposed above the UV radiation generator 118.

[0020]

[0021] The cooling chamber 102 includes a coolant distribution assembly 152. The coolant distribution assembly 152 includes a coolant gas inlet 154, a coolant source 156, and a coolant flow controller 158. The coolant gas inlet 154 is disposed in the cooling chamber 102. The coolant flow controller 158, such as a mass flow control (MFC) device, is in fluid connection with the coolant source 156 via a first coolant conduit 160. The coolant flow controller 158 controls the flow rate of the cooling gas from the coolant source 156. The coolant source 156 includes a cooling gas such as air, nitrogen gas (N2), or other suitable gas. The divider 104 prevents the cooling gas from mixing with the ozone disposed in the processing region 108. The cooling gas from the coolant source 156 passes through the coolant flow controller 158 and moves to the coolant gas inlet 154 via a second coolant conduit 162. The cooling gas exiting the coolant gas inlet 154 flows over the UV radiation generator 118 to the coolant gas outlet 164, removing the heat generated by the UV radiation generator 118.

[0021]

[0022] The coolant distribution assembly 152 is utilized to control the temperature of the UV radiation generator 118. To enhance the formation efficiency of atomic oxygen, it is desirable that the intensity of the UV radiation from the UV radiation generator 118 at a wavelength of approximately 254 nm entering the processing region 108 be high. To increase the intensity of the UV radiation emitted by the UV radiation generator 118, the power supplied to the UV radiation generator 118 is increased. The increase in power causes the release of heat from the UV radiation generator 118. The heat dissipation causes a drift in the emission spectrum of the UV radiation. The drift in the emission spectrum reduces the intensity of the UV radiation at 254 nm. The coolant distribution assembly 152 flows a cooling gas within the cooling region 106 to maintain the cooling region 106 at approximately 30°C to approximately 40°C. The cooling gas from the coolant source 156 flows over the UV radiation generator 118 to maintain the UV radiation generator 118 at a constant temperature.

[0022]

[0023] The temperature sensor 166 provides information used to determine the effectiveness of the cooling of the UV radiation generator 118. In one embodiment, the temperature sensor 166 determines the temperature of the cooling gas exiting the cooling region 106 and acquires information that it can be used to determine the temperature of the cooling region 106 and / or the UV radiation generator 118. The temperature sensor 166 communicates with the coolant flow controller 158 and the controller 138. The flow rate can be adjusted by the coolant flow controller 158 to either increase or decrease the temperature of the UV radiation generator 118 based on the measured value. Further, the UV intensity sensor 148 communicates with the coolant flow controller 158 and the controller 138. Based on the measured value of the UV intensity of the UV intensity sensor 148, the flow rate of the coolant entering the cooling region 106 can be adjusted by the coolant flow controller 158 to either increase or decrease the temperature based on the operating state of the UV radiation generator 118 or the amount of UV radiation sensed by the UV intensity sensor 148. One or both of the temperature sensor 166 and the UV intensity sensor 148 can be disposed in the atomic oxygen cleaning chamber 100.

[0023]

[0024] As shown in FIG. 1A, which can be combined with other embodiments described herein, the atomic oxygen cleaning chamber 100 includes a coolant pump 153. The coolant pump 153 is coupled to a coolant gas outlet 164, controls the coolant gas pressure within the cooling region 106, and vents excess coolant gas from the cooling region 106 through the coolant gas outlet 164 via a third coolant conduit 155.

[0024]

[0025] As shown in FIG. 1B, which can be combined with other embodiments described herein, the atomic oxygen cleaning chamber 100 includes a coolant recirculation assembly 168. The coolant recirculation assembly 168 is coupled between a coolant gas inlet 154 and a coolant gas outlet 164. The coolant recirculation assembly 168 includes a coolant flow line 170 and a heat exchanger 172. The coolant flow line 170 is in fluid communication with the coolant gas outlet 164 via a third coolant conduit 155. Coolant gas exits the cooling region 106 and enters the coolant recirculation assembly 168 by a pump (not shown). The coolant gas flows through the coolant flow line 170 to the heat exchanger 172. The heat exchanger 172 removes heat from the coolant gas to the external environment or another coolant fluid. The coolant gas flows from the heat exchanger 172 through the coolant flow line 170 to a coolant flow controller 158, where the recirculated coolant gas is reintroduced into the cooling region 106. Coolant gas is supplied from a coolant source 156 to the coolant flow line 170 via a first coolant conduit 160. The coolant gas passes through the coolant flow controller 158 and moves to the coolant gas inlet 154 via a second coolant conduit 162.

[0025]

[0026] FIG. 2 is a flowchart of a method 200 for cleaning a substrate 101 with atomic oxygen. For ease of explanation, FIG. 2 will be described with reference to FIGS. 1A and 1B. However, it should be noted that method 200 can be performed using an atomic oxygen cleaning chamber other than atomic oxygen cleaning chamber 100.

[0026]

[0027] In process 201, substrate 101 is transferred to atomic oxygen cleaning chamber 100. Atomic oxygen cleaning chamber 100 includes process chamber 103 and cooling chamber 102. Substrate 101 enters the processing area 108 of process chamber 103 through slit valve 114. Substrate 101 is positioned on pedestal 110 disposed in processing area 108. The first surface of substrate 101 is oriented toward ultraviolet (UV) radiation generator 118 disposed in cooling area 106 of cooling chamber 102. The distance 116 from UV radiation generator 118 to the upper surface 120 of pedestal 110 is from about 7 millimeters (mm) to about 30 mm.

[0027]

[0028] In process 202, a flow of ozone is supplied to processing area 108. The ozone gas is flowed into processing area 108 at a rate of from about 50 sccm to about 20000 sccm. The pressure in processing area 108 is maintained from about 0 psi to about 15 psi. The flow of ozone is distributed over the first surface of substrate 101 in processing area 108. The flow rate of ozone entering processing area 108 is controlled by flow controller 130 in communication with controller 138.

[0028]

[0029] In process 203, UV radiation generator 118 emits radiation. The radiation passes through divider 104 from cooling area 106 of cooling chamber 102 to processing area 108. UV radiation generator 118 is configured to emit radiation having a wavelength from about 240 nm to about 310 nm. The flow of ozone distributed over the first surface of substrate 101 in processing area 108 is exposed to the radiation and converted to oxygen gas (O2) and atomic oxygen (O). The oxygen gas and atomic oxygen oxidize organic materials such as hydrocarbons on the first surface of substrate 101, generating carbon dioxide (CO2) and water (H2O) as by-products.

[0029]

[0030] In operation 204, cooling gas enters cooling region 106. The cooling gas can be supplied from coolant source 156 and / or can be recycled through heat exchanger 172 into cooling region 106. The cooling gas is discharged from coolant source 156 through coolant gas inlet 154 into cooling region 106. The cooling gas flows over UV radiation generator 118 and maintains cooling region 106 and / or UV radiation generator 118 below a predetermined temperature. The predetermined temperature is from about 30°C to about 40°C. The flow rate of the cooling gas into cooling region 106 is from about 1 lpm to about 10 lpm. The pressure in cooling region 106 is from about 0 psi to about 15 psi. If atomic oxygen cleaning chamber 100 includes coolant pump 153, the cooling gas is removed from cooling region 106 using coolant pump 153. If atomic oxygen cleaning chamber 100 includes coolant recirculation assembly 168, the cooling gas moves through coolant flow line 170 to heat exchanger 172. Heat exchanger 172 removes heat from the cooling gas before it re-enters cooling region 106 through coolant gas inlet 154.

[0030]

[0031] The temperature of UV radiation generator 118 and / or cooling region 106 is controlled using one or both of controller 138, coolant flow controller 158, and temperature sensor 166 and UV intensity sensor 148. Temperature sensor 166 and / or UV intensity sensor 148 communicate with controller 138. Temperature sensor 166 and UV intensity sensor 148 are operable to obtain measurements that can respectively determine the temperature of the cooling gas or the UV intensity of the radiation. Temperature sensor 166 and UV intensity sensor 148 send a signal relaying temperature and intensity information to controller 138. The temperature of the cooling gas or the UV intensity of the radiation can be used to confirm the temperature of UV radiation generator 118. Controller 138, which communicates with coolant flow controller 158, is operable to control the flow rate of the cooling gas flowing into cooling chamber 102 based on the measurements of temperature sensor 166 and UV intensity sensor 148 to maintain UV radiation generator 118 at a desired temperature.

[0031]

[0032] In operation 205, the by-product is removed from the processing region 108. A pump 143 is coupled to the gas outlet 140 to exhaust the by-product from the processing region 108 through the gas outlet 140. In an optional operation 206, operations 202, 203, 204, and 205 are repeated for subsequent surfaces of the substrate 101. For example, the substrate 101 can be inverted so that the opposite side of the substrate 101 is exposed within the process chamber 103. At the end of method 200, the substrate 101 can be removed from the atomic oxygen cleaning chamber 100 for further processing.

[0032]

[0033] In summary, this specification describes an atomic oxygen cleaning chamber with temperature control of a UV radiation generator and a method for cleaning a substrate with atomic oxygen. By actively cooling the UV radiation generator, the UV radiation generator can be operated to generate higher-intensity UV radiation at a stable wavelength, i.e., without the wavelength drift typically associated with the output of a high-power UV radiation generator. The high-intensity output enables more atomic oxygen to achieve a fast reaction rate and oxidation ability compared to other oxygen-containing cleaning agents, and the substrate surface is cleaned quickly and efficiently. The atomic oxygen cleaning chamber includes an ozone generator that continuously supplies ozone to the processing region such that the radiation generated by the UV radiation generator converts the ozone to atomic oxygen in situ.

[0033]

[0034] While the foregoing is directed to embodiments of the present disclosure, it is possible to devise additional embodiments of the present disclosure without departing from its basic scope as determined by the following claims.

Claims

1. An atomic oxygen cleaning chamber, comprising: a process chamber; a cooling chamber coupled to the process chamber; a divider that hermetically separates the process chamber from the cooling chamber; an ultraviolet (UV) radiation generator disposed in the cooling chamber and operable to supply UV radiation into the process chamber through the divider; a pedestal disposed in the process chamber; a gas distribution assembly operable to distribute ozone onto the upper surface of the pedestal; a coolant distribution assembly operable to distribute a coolant gas within the cooling chamber to cool the UV radiation generator; at least one of a temperature sensor configured to provide a measurement indicative of the temperature of the UV radiation generator within the cooling chamber and a UV intensity sensor operable to provide a measurement indicative of the UV intensity of the UV radiation emitted from the UV radiation generator into the process chamber; and a controller; wherein the controller is operable to control the flow rate of the coolant gas entering the cooling chamber based on the measurement of at least one of the temperature sensor and the UV intensity sensor. An atomic oxygen cleaning chamber.

2. The atomic oxygen cleaning chamber according to claim 1, further comprising a coolant flow line operable to couple a coolant gas inlet of the cooling chamber to a coolant gas outlet of the cooling chamber to recirculate the coolant gas through the cooling chamber.

3. The atomic oxygen cleaning chamber according to claim 2, further comprising a heat exchanger coupled between the coolant gas inlet and the coolant gas outlet of the cooling chamber. An atomic oxygen cleaning chamber.

4. The gas distribution assembly comprises: a gas inlet disposed in the process chamber and coupled to the gas distribution assembly; and a gas outlet disposed in the process chamber and coupled to a pump. The atomic oxygen cleaning chamber according to claim 1.

5. The gas distribution assembly further comprises: an oxygen-containing gas source; an ozone generator in communication with the oxygen-containing gas source; and a flow controller operable to control the flow rate of ozone entering the process chamber and in communication with the ozone generator. The atomic oxygen cleaning chamber according to claim 4.

6. The atomic oxygen cleaning chamber according to claim 1, further comprising a coolant pump coupled to an outlet formed in the cooling chamber.

7. The atomic oxygen cleaning chamber according to claim 1, wherein a reflector is disposed in the cooling chamber and above the UV radiation generator.

8. The atomic oxygen cleaning chamber according to claim 1, wherein the divider is made of a fused silica material.

9. The atomic oxygen cleaning chamber according to claim 1, wherein the pedestal includes a processing position corresponding to a distance from the UV radiation generator to the upper surface of the pedestal.

10. The atomic oxygen cleaning chamber according to claim 9, wherein the distance from the UV radiation generator to the upper surface of the pedestal is from 7 mm to 30 mm.

11. An atomic oxygen cleaning chamber, a process chamber, a cooling chamber coupled to the process chamber, a divider that hermetically separates the process chamber from the cooling chamber, an ultraviolet (UV) radiation generator disposed in the cooling chamber and operable to supply UV radiation into the process chamber through the divider, a pedestal disposed in the process chamber, a gas distribution assembly operable to distribute ozone onto the upper surface of the pedestal, a coolant distribution assembly having a coolant gas inlet, a coolant gas outlet, a coolant gas source operable to distribute cooling gas throughout the cooling chamber, and a coolant pump operable to send the cooling gas to the coolant gas outlet throughout the cooling chamber, at least one of a temperature sensor configured to provide a measured value indicating the temperature of the UV radiation generator in the cooling chamber and a UV intensity sensor operable to provide a measured value indicating the UV intensity of the UV radiation emitted from the UV radiation generator into the process chamber, a controller, and comprising, The controller is operable to control the flow rate of the cooling gas entering the cooling chamber based on a measured value of at least one of the temperature sensor and the UV intensity sensor. The atomic oxygen cleaning chamber.

12. The atomic oxygen cleaning chamber according to claim 11, further comprising a coolant flow line operable to couple the coolant gas inlet of the cooling chamber to the coolant gas outlet of the cooling chamber and recirculate the cooling gas through the cooling chamber.

13. A heat exchanger coupled between the coolant gas inlet and the coolant gas outlet of the cooling chamber The atomic oxygen cleaning chamber according to claim 12, further comprising.

14. A method of cleaning a substrate with atomic oxygen, comprising: Positioning the substrate on the upper surface of a pedestal disposed in a process chamber; Flowing ozone into the process chamber and distributing the ozone over the substrate; Flowing a cooling gas into a cooling chamber to maintain the temperature of a UV radiation generator below a predetermined temperature; Supplying radiation having a wavelength from about 240 nanometers (nm) to about 310 nm from a UV radiation generator disposed in the cooling chamber to the ozone disposed in the process chamber; Measuring at least one of the temperature of the UV radiation generator in the cooling chamber and the UV intensity of the radiation in the process chamber; Controlling the flow rate of the cooling gas entering the cooling chamber based on at least one of the measured temperature and the measured UV intensity A method comprising.

15. The method according to claim 14, further comprising recirculating the cooling gas through the cooling chamber.

16. The method according to claim 15, further comprising flowing the cooling gas exiting the cooling chamber through a heat exchanger before recirculating the cooling gas.

17. The method according to claim 14, wherein supplying the radiation further comprises passing the radiation through a divider that hermetically separates the cooling chamber from the process chamber.

18. The method according to claim 14, wherein the predetermined temperature is from about 30 °C to about 40 °C.

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