COOLING SYSTEM WITH ANTIFREEZE FOR COOLING MAGNETRON FOR PROCESS CHAMBER OF PROCESSING SYSTEM

Abstract: A vacuum processing system has a process chamber with a rotating member, such as a magnetron in a PVD chamber, disposed in a cooling chamber containing a free oxygen deficient cooling fluid that circulates into and out of the cooling chamber. The free oxygen deficient cooling fluid may be an ethylene-glycol based coolant or antifreeze. Conduits connect an inlet and an outlet of the cooling chamber to a heat exchanger to cool and re-circulate the free oxygen deficient cooling fluid.

Description: COOLING SYSTEM WITH ANTIFREEZE FOR COOLING MAGNETRON FOR PROCESS CHAMBER OF PROCESSING SYSTEM BACKGROUND OF THE INVENTION Field of the Invention The present invention generally relates to methods and apparatuses used to fabricate integrated circuits and flat panel displays. Specifically, the present invention relates to methods and apparatuses for cooling a rotating element in or about a process chamber of a vacuum processing system. Background of the Related Art Vacuum processing systems for processing 150mm, 200mm, 300mm or other size wafers, or substrates, are generally known. A vacuum processing system typically has a central transfer chamber mounted on a monolith platform. The transfer chamber is the center of activity for the movement of wafers being processed in the system. Some transfer chambers have multiple facets for mounting chambers of various different types, including process chambers. The process chambers include, among others, rapid thermal processing (RTP) chambers, physical vapor deposition (PVD) chambers, chemical vapor deposition (CVD) chambers, and etch chambers. The process chambers perform various processes on the substrates to form integrated circuits or other structures thereon. The processes for fabricating IC's or other structures on a substrate, or wafer, typically involve operating in a vacuum environment in a process chamber. Additionally, many of these processes involve generating an ionized plasma discharge in a region of the chamber near the substrate either to strike the substrate with the ions to remove material therefrom or to strike a target with the ions to sputter the target material onto the substrate. For example, a physical vapor deposition process typically generates a plasma discharge between a substrate and a target in a very high vacuum. The positive ions in the plasma discharge are accelerated toward the target to dislodge the target material, which then deposits onto the substrate. For instance, in order to sputter copper or aluminum onto a substrate, a target made of copper or aluminum is mounted in the PVD chamber. A substrate is positioned near the target and a plasma of ions, typically of argon, is generated in the space between the substrate and the target, 2 and the ions are accelerated toward the target. The target material is knocked loose from the target and travels onto the surface of the substrate, thereby depositing a thin film of the target material on the substrate. Electrons in the plasma material, along with secondary electrons dislodged from the target material, are attracted to a grounded surface in the chamber, but before these electrons are captured by the grounded surface, they typically undergo a sufficient number of ionizing collisions in the plasma to maintain the plasma discharge. Among other methods, plasma discharges are typically formed in the process chamber by RF voltages, microwaves, planar magnetrons or a combination of techniques. A planar magnetron system, for example, uses a rotating magnetron disposed above a target, and either a DC bias between the target and the substrate or an RF source, coupled into the space between the target and substrate, for powering the discharge to form the plasma. The magnetron is a magnet structure which provides magnetic field lines parallel to, and spaced to the plasma side, of the sputter surface of the target. A negative DC bias voltage between the target and the plasma region accelerates the ions toward the target to dislodge the target material therefrom. The magnetic field from the magnetron confines the free electrons, including the secondary electrons from the target material, near the target to maximize the ionizing collisions by the free electrons with the plasma material before the free electrons are lost to a grounded surface. Where the magnetron is one or more fixed magnets, they typically rotate around the backside of the target to evenly spread the magnetic field around the surface of target to result in an even sputtering of the target material. A simplified example of a PVD chamber 100 is shown in Figure 1. Generally, the PVD chamber 100 comprises a substrate support member 102, a target 104 and a magnetron 108. The magnetron is disposed within a cooling chamber 116 which is defined by a top 117, sides 119 and the target 104. A cooling fluid, such as water, flows through the cooling chamber 116 to cool the magnetron 108 and the target 104. Figure 2 is a cross sectional view of the magnetron 108. The magnetron 108 has a magnet assembly including several magnets 110 typically made of an iridium- boron-iron (NdBFe) compound disposed between two stainless steel poles 109, 111. The stainless steel poles 109, 111 cover the top and the bottom of the magnets 110 to 3 effectively create a more uniform magnetic field across the surface area of the magnetron 108. A substrate (not shown) is placed on the substrate support member 102 and raised to a position near the target 104 inside the chamber section 106. The pump section 122, typically including a cryopump or other high vacuum pump, evacuates the chamber 100 down to a very high vacuum. A motor assembly 112 provides rotational motion to the magnetron 108 through a shaft 114 to rotate the magnetron 108 at about 100 rpm behind the target. The plasma is struck in the space between the wafer and the target 104, and ions in the plasma strike the target 104. The process may heat up the target 104 and the magnetron 108 to about 110°C- 120°C and about 130°C-140°C, respectively. If the magnetron 108 and/or the target 104 are heated above acceptable temperatures, then the high temperature may alter the performance of the process giving undesirable results and lessening the useful lives of the magnetron 108 and the target 104. In the performance of the process, the rate of sputtering depends on, among other parameters, the number and energy level of the ions in the plasma and the energy level of the molecules of the target material. Fewer ions in the plasma means fewer target molecules will be struck and freed from the target resulting in a lower sputtering rate. Whereas, a higher energy level in the ions means there is more energy available to sputter more target molecules, and a higher energy level in the target material means more target material can be sputtered free with the same ion energy, both resulting in a higher sputtering rate. As the target heats up, heat will radiate to the plasma, and since gases tend to expand as temperatures increase, the density of the plasma will decrease (assuming that the pump section 122 can maintain the same pressure level), so the number of ions will decrease, but the energy level of the ions will increase along with the energy level of the target material. These offsetting effects of increased temperature cause unpredictable results in the process. Additionally, the excessive heat may cause the mechanical features of the magnetron 108 and target 104 to wear out prematurely. The target 104 is under water pressure on the top side and under a vacuum on the other side, for example, so these forces may cause the target to bow as it's mechanical strength lessens due to an increase in temperature. Additionally, the magnets may become permanently demagnetized if their temperature exceeds their Curie point, thereby losing the magnetic field from the 4 magnetron. Therefore, water in the cooling chamber 116 is used to cool the magnetron 108 and the back side of the target 104. The water enters the cooling chamber 116 at an inlet 118, circulates around the magnetron 108 and exits at an outlet 120. The arrows A-F show generalized water flow paths around the magnetron 108. The magnets 110 are susceptible to corrosion, or oxidation, due to the presence of dissolved oxygen in the water circulating around the magnetron 108. Thus, the performance of the magnetron 108 may degrade over time due to the corrosion of the magnets 110. Corrosion of the magnets, for example, may reduce the mass of the magnetic material, thereby reducing the magnetic strength of the magnets. Additionally, as the magnets corrode, ions of the magnetic material may dissolve into the water, reducing the water resistivity, which must be maintained above a certain level for insulation. One solution to the magnets corrosion issue is to encapsulate the magnets 110 in a stainless steel shell (not shown). The stainless steel shell does not interfere with the performance of the magnets 110 or magnetron 108, and prevents the corrosive water from reaching the magnets 110. However, this solution is costly and complex requiring additional parts and assembly cost. Therefore, a need exists for a process chamber with a cooling fluid that flows between a rotating member, such as a magnetron in a PVD chamber, and a surface, such as the top side of a sputtering target. Summary of the Invention A vacuum processing system has a process chamber with a rotating member, such as a magnetron in a PVD chamber, disposed in a cooling chamber containing a free oxygen deficient cooling fluid that circulates into and out of the cooling chamber. The free oxygen deficient cooling fluid may be any suitable fluid that does not react with the exposed parts of the magnetron assembly. One such fluid is commonly known as antifreeze, such as an ethylene-glycol based coolant. Conduits connect an inlet and an outlet of the cooling chamber to a heat exchanger to cool and re-circulate the free oxygen deficient cooling fluid. Brief Description of the Drawings So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, a more particular 5 description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. Figure 1 is a side view of a process chamber. Figure 2 is a side view of a magnetron. Figure 3 is a schematic representation of a cooling system. Figure 4 is a side view of an alternative process chamber. Figure 5 is a top schematic view of a vacuum processing system. Detailed Description of the Preferred Embodiment Figure 1 shows a simplified example of a PVD chamber 100. The PVD chamber 100 generally includes a chamber section 106 and a pump section 122. The chamber section 106 generally includes a substrate support member 102 for supporting a substrate (not shown) to be processed, a target 104 for providing a material to be deposited on the substrate and a process environment 103 wherein a plasma of ions is generated to sputter the target 104. Although the below described magnetron and cooling system will be described with reference to a process chamber having the configuration of the PVD chamber 100, it is understood that the invention is not so limited. Rather, the process chamber may be any type of process chamber and may be configured with the substrate support member and process environment above or to the side of, as well as below, the target. Thus, any indications of up, down or other directions are only references and not meant to limit the invention. The pump section 122 typically includes a cryopump, or other high vacuum pump, for pumping the chamber section 106 to a very high vacuum, so the chamber section 106 may process a substrate (not shown). A gate valve 105 is disposed between the chamber section 106 and the cryopump 122 to provide access therebetween so the cryopump 122 can reduce the pressure in the chamber section 106 and to provide isolation therebetween so the chamber section 106 may be vented. The PVD chamber 100 generally includes the substrate support member 102, also known as a susceptor or heater, disposed within the chamber section 106 for receiving the substrate from a transfer chamber 202 (Figure 5). The substrate support 6 member 102 may heat the substrate if required by the process being performed. A target 104 is disposed in the top of the chamber section 106 to provide material, such as aluminum, copper, titanium, tungsten or other deposition material, to be sputtered onto the substrate during processing by the PVD chamber 100. A lift mechanism, including a guide rod 126, a bellows 128 and a lift actuator 130 mounted to the bottom of the chamber section 106, raises the substrate support member 102 to the target 104 for the PVD chamber 100 to perform the process and lowers the substrate support member 102 to exchange substrates. A shield 132, disposed within the chamber section 106, surrounds the substrate support member 102 and the substrate during processing in order to prevent the target material from depositing on the edge of the substrate and on other surfaces inside the chamber section 106. Situated above the chamber section 106 and sealed from the processing region of the chamber 100 is a magnetron assembly, which includes a cooling chamber 116 and magnetron 108. The cooling chamber 116 is generally defined by a bottom plate (not shown), a top 117 and sides 119. A free oxygen deficient cooling fluid flows into the cooling chamber 116 through inlet 118 and out of the cooling chamber 116 through outlet 120, at a rate of about three gallons per minute. The magnetron 108 is rotatably disposed in the cooling chamber 116 on the non-process environment side of the target 104 and surrounded by the free oxygen deficient cooling fluid. Unlike water containing dissolved oxygen, the free oxygen deficient cooling fluid is chemically formulated to prevent reaction with the materials of the magnetron 108, described below. For example, the free oxygen deficient cooling fluid may be the type of coolant commonly known as antifreeze or an alcohol, such as an ethylene-glycol based coolant. Other suitable coolant fluids may be apparent to a person skilled in the art. The magnetron 108 is isolated from the vacuum in the chamber section 106 by seals (not shown) between the cooling chamber 116 and target 104 and between the target 104 and the processing region. The magnetron 108 (shown by itself in Figure 2) has a set of iridium/boron/iron (NdBFe) magnets 110 arranged within the magnetron 108 so that they create magnetic field lines which are rotated across the sputtering surface of the target. Electrons are captured or trapped along these lines, where they collide with gas atoms, creating ions at the surface of the target 104. To create this effect about the circumference of the target, the magnetron 108 is rotated during 7 processing. A top pole 109 and a bottom pole 111 made of stainless steel contact the magnets 110 on the top and the bottom of the magnetron 108 and are magnetically polarized by the magnets 110. Thus, rather than presenting field lines from several discrete magnets, the poles 109, 111 of the magnetron 108 function to present a single magnet, albeit one with varying field lines between the individual magnets 110. The poles 109, 111 effectively smooth out the field lines between the magnets 110, so the magnetron 108 creates the field lines more evenly across the plasma-side surface of the target 104. The magnetron 108 is situated above the top side of the target 104 with about a one millimeter gap therebetween, so the magnetic field lines from the magnets 110 may penetrate through the target 104. A motor assembly 112 for rotating the magnetron 108 is mounted to the top 117 of the cooling chamber 116. A shaft 114, which mechanically couples the motor assembly 112 to the rotational center of the magnetron 108, extends through the top 117 to impart a rotational motion to the magnetron 108 to cause it to spin at about 100 rpm during performance of the wafer process. A negative dc bias voltage of about 200 V or more is typically applied to the target 104, and a ground is applied to an anode, the substrate support member 102, and the chamber surfaces. The combined action of the dc bias and the rotating magnetron 108 generate an ionized plasma discharge in a process gas, such as argon, between the target 104 and the substrate. The positively charged ions are attracted to the target 104 and strike the target 104 with sufficient energy to dislodge atoms of the target material, which sputters onto the substrate. The freed electrons from the process gas and secondary electrons from the target 104 undergo sufficient collisions to maintain the plasma discharge in the process gas because the magnetic fields of the magnetron 108 confine the electrons to a region close to the target 104 in order to maximize the opportunity for ionizing collisions near the target 104 before the electrons are lost to a grounded surface. In this manner, the magnetron 108 also "shapes" the plasma typically into a circular plasma ring in a containment field near the target. The action of the bias voltage and the magnetic fields causes a considerable amount of the energy of the process to be dissipated at the target 304 and magnetron 308. Thus, despite being cooled, the target 304 may heat up to about 130°C - 140°C during substrate processing, and the magnetron 308 may heat up to about 110°C - 8 120°C. Therefore, the free oxygen deficient cooling fluid must be circulated to cool the magnetron 308 and the target 304. Figure 3 schematically shows a cooling system 150 for circulating the free oxygen deficient cooling fluid through the cooling chamber 116 and around the magnetron 108. Unlike water, which was used as the cooling fluid in the prior art, a specialized free oxygen deficient cooling fluid, such as antifreeze, which contains minimal free oxygen to react with the magnets, does not have a constantly replenished supply, so the free oxygen deficient cooling fluid must be re-circulated into the cooling chamber 116. Thus, an outflow conduit 152 and an inflow conduit 156 connect the cooling chamber 116 to a heat exchanger 154 for cooling the free oxygen deficient cooling fluid and re-circulating it to the cooling chamber 116. Although the invention is described with reference to the magnetron 108 shown in Figures 1 and 2, it is understood that the invention is not limited to use with this particular magnetron, but may be used with any magnetron. Thus, Figure 4 is provided to show a simplified example of another PVD chamber 300 having an alternative magnetron 308 which may be used with the present invention. The chamber 300 has the same general structure and function as the chamber 100 shown in Figure 1 and generally includes a chamber section 306, a pump section 307 and a gate valve 305 therebetween. The chamber section 306 generally includes a substrate support member 302 for supporting a substrate (not shown) to be processed, a target 304 for providing a material to be deposited on the substrate, a process environment 303 wherein a plasma is created for ions to sputter the target 304, a lift assembly 328 for raising the substrate support member 302 to a processing positioning, a cooling chamber 316 above the target 304, a rotating magnetron 308 disposed in the cooling chamber 316 and a motor assembly 312 for rotating the magnetron 308. Generally, the rotational motion of the magnetron 308 is used to induce the free oxygen deficient cooling fluid surrounding the magnetron 308 to circulate through and around the magnetron 308, especially through the space between the magnetron 308 and the top surface of the target 304, in order to efficiently cool the magnetron 308 and the target 304. Near its rotational center, the magnetron 308 has two fluid passageways, or suction tubes, 338 extending from the bottom of the magnetron 308 to the top of the magnetron 308. At the bottom of the magnetron 308, the passageways 9 338 have inlets open to the space between the magnetron 308 and the target 304. At the top of the magnetron 308, the fluid passageways 338 open into two fluid channels 340. The fluid channels 340 extend from the fluid passageways 338 near the rotational center of the magnetron 308 to channel openings, or outlets, 345 at the outer edge of the magnetron 308. The fluid passageways 338 and the fluid channels 340 form fluid conduits through which the free oxygen deficient cooling fluid flows from the space between the magnetron 308 and the target 304 near the rotational center of the magnetron 308 to the top outer edge of the magnetron 308. The rotational motion of the magnetron 308 causes a centrifugal force which induces the free oxygen deficient cooling fluid in the fluid channels 340 to flow to the outer edge of the top surface of the magnetron 308. Thus, the free oxygen deficient cooling fluid is forced to move to the top outer edge of the magnetron 308. Under the centrifugal force in the fluid channel 340, the free oxygen deficient cooling fluid is drawn up from the space between the magnetron 308 and the target 304 through the passageway 338. The evacuation of the free oxygen deficient cooling fluid from the space near the rotational center of the magnetron 308 between the target 304 and the magnetron 308 causes the free oxygen deficient cooling fluid to flow inward from the outer edge of the bottom of the magnetron 308 and thereby through the space between the magnetron 308 and target 304. A space between the magnetron 308 and the sides 319 permits the free oxygen deficient cooling fluid to flow down beside the magnetron 308 to the bottom of the magnetron 308 in order to complete the circulation of the free oxygen deficient cooling fluid . The cool free oxygen deficient cooling fluid flowing in through inlet 318 mixes with the warm free oxygen deficient cooling fluid circulating around the magnetron 308, and the warm free oxygen deficient cooling fluid flows out through the outlet 320. In operation, the rotation of the magnetron 308 causes the free oxygen deficient cooling fluid to flow between the magnetron 308 .and the target 304. The heat from the bottom of the magnetron 308 and from the target 304 transfers into the free oxygen deficient cooling fluid as the free oxygen deficient cooling fluid circulates. The heated free oxygen deficient cooling fluid flows out through the fluid conduit 338, 340 where it is mixed with the cooler free oxygen deficient cooling fluid in the cooling chamber 316. The flow of free oxygen deficient cooling fluid through the inlet 318 and outlet 10 320 ports of the cooling chamber 316 keeps a steady supply of cool free oxygen deficient cooling fluid coming into the cooling chamber 316 while heated free oxygen deficient cooling fluid exits the cooling chamber 316. Thus, the magnetron 308 and the target 304 are efficiently cooled by rapidly circulating free oxygen deficient cooling fluid . The System: A vacuum processing system which may incorporate the above described invention will now be described. Figure 5 generally shows a schematic top view of an embodiment of a vacuum processing system 200. The system 200 shown in Figure 5 is an example of the Endura ™ system available from Applied Materials, Inc. Although the invention may be practiced with this system 200, it is understood that other types of vacuum processing systems may be used with the present invention, and the present invention is not limited to any particular type of vacuum processing system. The vacuum processing system 200 includes a transfer chamber 202 and a buffer chamber 203 typically mounted on a platform (not shown) and generally forming a system monolith. The system monolith has two load lock chambers 208 mounted at facets 212. A mini-environment 214 optionally attaches to the load lock chambers 208. The transfer chamber 202 has four process chambers 204, such as chambers 100, 300, mounted at facets 206. The process chambers 204 perform the primary wafer process on the wafers in the vacuum processing system 200. Process chambers 204 may be any type of process chamber, such as a rapid thermal processing chamber, a physical vapor deposition chamber (PVD), a chemical vapor deposition chamber, an etch chamber, etc. The process chambers 204 may have a cooling chamber with a rotating member, such as the magnetrons 108, 308 described above. The chambers 204 attach to the transfer chamber 202 at facets 206. A slit valve opening in the side of the chambers 204 provides access for the transfer chamber robot 220 to insert or remove a substrate 222 into or from the chamber section 306. The process chambers 204 may be supported by the transfer chamber 202 or may be supported on their own platforms depending on the configuration of the individual process chambers 204. Slit valves (not shown) in the facets 206 provide access and isolation between the transfer chamber 202 and the process chambers 204. 11 A pre-clean chamber 228 and a cool-down chamber 230 are disposed between the transfer chamber 202 and the buffer chamber 203. The pre-clean chamber 228 cleans the wafers before they enter the transfer chamber 202, and the cool-down chamber 230 cools the wafers after they have been processed in the process chambers 204. The pre-clean chamber 228 and the cool-down chamber 230 may also transition the wafers between the vacuum levels of the transfer chamber 202 and the buffer chamber 203. The buffer chamber 203 has two expansion chambers 232 for performing additional processes on the wafers. The buffer chamber 203 further has a cool-down chamber 234 for further cooling the wafers if necessary. A location for an additional chamber 236, such as a wafer aligner chamber or an additional pre-processing or postprocessing chamber, is provided on the buffer chamber 203. The load lock chambers 208 transition one wafer at a time between the ambient environment pressure to the buffer chamber vacuum pressure. Openings (not shown) in facets 212 provide access and valves provide isolation between the load lock chambers 208 and the buffer chamber 203. Correspondingly, the load lock chambers 208 have openings on their surfaces that align with the openings in facets 212. The load lock chambers 208 and the mini-environment 214 have corresponding openings (not shown) providing access therebetween, while doors (not shown) for the openings provide isolation. Prior to the introduction of 300-mm wafers in the semiconductor processing industry, cassettes of wafers were typically loaded by human operators directly into the load lock chambers 208. Thus, a mini-environment 214 was not present in the system 200. More recently, however, semiconductor fabrication facilities have been including a mini-environment 214 to enter the wafers into the processing system 200 from cassettes of wafers transported by a factory automation handling system. The present invention contemplates incorporation in both types of systems 200. The mini-environment 214 has four pod loaders 216 attached on its front side 238 for receiving wafer cassettes from the factory automation. Openings (not shown) with corresponding doors 226 provide access and isolation between the mini- environment 214 and the pod loaders 216. The pod loaders 216 are mounted on the side of the mini-environment 214 and are essentially shelves for supporting the wafer 12 cassettes, or pods, (not shown) used to transport the wafers to and from the vacuum processing system 200. A robot 220, or wafer handler, is disposed within the transfer chamber 202 for transferring a wafer 222 between the pre-clean chamber 228 and the cool-down chamber 230 and the process chambers 204. A similar robot 221 is disposed within the buffer chamber 203 for transferring a wafer 223 between the load lock chambers 208, the expansion chambers 232, the cool-down chamber 234, the additional chamber 236, the pre-clean chamber 228 and the cool-down chamber 230. Likewise, a robot 224 is disposed within the mini-environment 214 for transferring the wafers between the pod loaders 216 and the load lock chambers 208. The robot 224 is typically mounted on a track so the robot 224 can move back and forth in the mini-environment 214. While the foregoing is directed to the preferred embodiment of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims which follow.

Claims: 13 Claims: 1. A cooling system for cooling a heat generating element disposed adjacent a process chamber, comprising: a cooling chamber for housing the heat generating element; a free oxygen deficient cooling fluid flowing within the cooling chamber and for surrounding .and cooling the heat generating element; a coolant inlet to the cooling chamber permitting the free oxygen deficient cooling fluid to flow into the cooling chamber at a first temperature; and a coolant outlet from the cooling chamber permitting the free oxygen deficient cooling fluid to flow out of the cooling chamber at a second temperature higher than the first temperature. 2. The cooling system of claim 1 further comprising a heat exchanger connected to the coolant inlet and the coolant outlet, receiving the free oxygen deficient cooling fluid from the cooling chamber, cooling the free oxygen deficient cooling fluid and circulating the free oxygen deficient cooling fluid back to the cooling chamber. 3. The cooling system of claim 1 wherein the free oxygen deficient cooling fluid is an antifreeze. 4. The cooling system of claim 1 wherein the free oxygen deficient cooling fluid is an alcohol. 5. The cooling system of claim 1 wherein the free oxygen deficient cooling fluid is an ethylene-glycol based coolant. 6. The cooling system of claim 1 wherein the rotating member is a magnetron. 7. A chamber for use in a vacuum processing system for performing a process on a substrate, comprising: a cooling chamber containing a free oxygen deficient cooling fluid; 14 a rotating member disposed within the cooling chamber for performing a function for at least part of the process performed on the substrate, the free oxygen deficient cooling fluid surrounding and cooling the rotating member; a coolant inlet to the cooling chamber permitting the free oxygen deficient cooling fluid to flow into the cooling chamber at a first temperature; and a coolant outlet from the cooling chamber permitting the free oxygen deficient cooling fluid to flow out of the cooling chamber at a second temperature higher than the first temperature. 8. The process chamber of claim 7 wherein the free oxygen deficient cooling fluid is an ethylene-glycol based coolant. 9. The process chamber of claim 7 wherein the free oxygen deficient cooling fluid is an antifreeze. 10. The process chamber of claim 7 wherein the rotating member is a magnetron. 11. A vacuum processing system, comprising: a process chamber for processing a substrate; a cooling chamber disposed within the process chamber; a heat generating element disposed within the cooling chamber; a free oxygen deficient cooling fluid flowing within the cooling chamber and surrounding and cooling the heat generating element; a coolant inlet to the cooling chamber permitting the free oxygen deficient cooling fluid to flow into the cooling chamber at a first temperature; and a coolant outlet from the cooling chamber permitting the free oxygen deficient cooling fluid to flow out of the cooling chamber at a second temperature higher than the first temperature. 12. The vacuum processing system of claim 11 further comprising: a heat exchanger connected to the coolant inlet and the coolant outlet, receiving the free oxygen deficient cooling fluid from the cooling chamber, cooling the free oxygen deficient cooling fluid and circulating the free oxygen deficient cooling fluid back to the cooling chamber. 15 13. The vacuum processing system of claim 11 wherein the free oxygen deficient cooling fluid is an ethylene-glycol based coolant. 14. The vacuum processing system of claim 11 wherein the free oxygen deficient cooling fluid is an antifreeze. 15. The vacuum processing system of claim 11 wherein the rotating member is a magnetron.

Inventors: FU JIANMING, SINHA ASHOK K, FU, JIANMING, SINHA, ASHOK, K.
Applicants: APPLIED MATERIALS INC, APPLIED MATERIALS, INC.
Application year: 1999
Main classification: H01J37
IPC codes: C23C14, H01J37, H01L21, H05H1