Semiconductor process cooling system

Abstract

Described herein is a process cooling system comprising a heat exchanger comprising a first inlet, a first outlet, a second inlet and a second outlet. The process cooling system also comprises a process cooling water supply manifold coupled to the first inlet of the heat exchanger. A proportional valve is coupled to the first outlet of the heat exchanger. A conduit is in thermal contact with a wall of a process chamber. A first end of the conduit is coupled to the proportional valve and a second end of the conduit is coupled to the second inlet of the heat exchanger. A process cooling water return manifold is coupled to the second outlet of the heat exchanger.

Description

SEMICONDUCTOR PROCESS COOLING SYSTEMCLAIM OF PRIORITY

[0001] This application is a non-provisional of, and claims the benefit of priority to, U.S. Provisional Patent Application No. 63 / 578,958, filed August 25, 2023, titled “SEMICONDUCTOR PROCESS COOLING SYSTEM,” and which is incorporated by reference in its entirety.BACKGROUND

[0002] Process systems are used in the semiconductor industry to perform fabrication processes within a vacuum chamber, such as thin film deposition and etching on semiconductive and insulative wafer substrates. Such process systems may comprise one or more process modules in which chemical vapor deposition (CVD), including plasma- enhanced chemical vapor deposition (PECVD) and atomic layer deposition (ALD) processes can be performed. In many applications, such processes demand high substrate temperatures. For example, substrate temperatures can frequently exceed 500°C, and be as high as 700°C. At such temperatures, heat radiation is a principal mode of heat transfer to other parts of the process system that are not mechanically coupled to the substrate. In one example, chamber walls, showerheads, etc., may be heated to elevated temperatures due to heat radiation emanating from a heated wafer pedestal. Chamber walls may comprise aluminum or steel, and can become excessively hot. Cooling systems based on flowing cooling water through copper or steel tubing are frequently employed to mitigate chamber temperatures.Conventional process cooling systems may stress tubing by pulsing cooling water flow through the tubing, causing thermal shock of the tubing. Damage to the tubing may ensue.BRIEF DESCRIPTION OF THE DRAWINGS

[0003] Fig. 1 illustrates a block diagram of a first process cooling system, in accordance with at least one implementation.

[0004] Fig. 2 illustrates a block diagram of a second process cooling system, in accordance with at least one implementation.

[0005] Fig. 3 illustrates a block diagram of a third process cooling system, in accordance with at least one implementation.

[0006] Fig. 4 illustrates a block diagram of a fourth process cooling system, in accordance with at least one implementation.

[0007] Fig. 5 illustrates a block diagram of a fifth process cooling system, in accordance with at least one implementation.

[0008] Fig. 6 illustrates a flow chart of a method to operate a process cooling system, in accordance with at least one implementation.DETAILED DESCRIPTION

[0009] At least one implementation describes an apparatus and method for a process cooling system that can be employed for semiconductor manufacture. In at least one implementation, the process cooling system comprises a heat exchanger coupled to a proportional valve. In at least one implementation, a supply of cold process cooling water is coupled to a first inlet of the heat exchanger. In at least one implementation, a first end of a cooling conduit is coupled with (e.g., in thermal contact) a process chamber is coupled to an outlet of the proportional valve.

[0010] In at least one implementation, a second end of the conduit is coupled to a second inlet of the heat exchanger. In at least one implementation, process cooling water flowing through the cooling conduit is heated by thermal contact of the conduit with heated walls of the process chamber. In at least one implementation, heated process cooling water is circulated to the second inlet of the heat exchanger and flows through the heat exchanger to a second outlet. In at least one implementation, the cold process cooling water flows into the heat exchanger through the first inlet.

[0011] In at least one implementation, the cold stream and the hot stream flow in a cocurrent flow configuration. In at least one implementation, the cold stream and the hot stream flow in a countercurrent flow configuration through the heat exchanger. In at least one implementation, the cold process cooling water may be thermally preconditioned (e.g., heated) to a temperature that is between the temperature of the cold process cooling water and the heated process cooling water entering the heat exchanger.

[0012] In at least one implementation, preconditioned process cooling water enters the cooling conduit. In at least one implementation, preconditioned process cooling water may mitigate damage to conduit walls that can result from thermal shock of unconditioned cold water entering the conduit under pulsed flow that may be employed in conventional process cooling systems.

[0013] In at least one implementation, the proportional valve may be adjusted to regulate continuous flow of the preconditioned process cooling water. In at least one implementation, the regulation of flow of the preconditioned process cooling water may enable smoothregulation of the temperature of process chamber walls, whereby temperature excursions of the walls may be mitigated by employment of a proportional valve. Similarly, temperature excursions of conduit walls may be mitigated or eliminated. In at least one implementation, a proportional valve may replace a directional valve in a process cooling system, whereby the directional valve may operate by setting a binary on or off state. In at least one implementation, the proportional valve may be a two-way valve. In at least one implementation, the proportional valve may be a four-way valve. In at least one implementation, directional valves may be employed for pulsed flow of process cooling water. In a process cooling system that does not employ a heat exchanger, pulsed flow may lead to damage to the cooling conduit by thermally shocking tubing walls. The on and off nature of pulsed flow may permit temperature excursions of the conduit, whereby the walls of the conduit are heated to relatively high temperatures.

[0014] For example, tubing walls may be heated to 90°C. Periodic introduction of unconditioned cold cooling water at room temperature may thermally shock the tubing causing sudden contraction. Subjugation of the cooling conduit to periodic temperature cycling such as encountered in a process cooling systems may cause damage to the cooling conduit. The ensuing damage may be cracking and splitting of the tubing, as well as detachment from the process chamber itself.

[0015] The disclosed process cooling system enables mitigation of such damage by employment of a heat exchanger for preconditioning of cold process cooling water to more moderate temperatures, whereby thermal shock to tubing walls is mitigated, in accordance with at least one implementation. Thermal shock to cooling conduit is further mitigated by employment of a proportional valve to enable smooth regulation of process chamber wall temperatures, and thereby conduit wall temperatures, in accordance with at least one implementation.

[0016] In the following description, well-known methods and devices are shown in block diagram form, rather than in detail, to avoid obscuring the present disclosure. Reference throughout this specification to “an implementation” or “one implementation” “at least one implementation,” or “some implementations” means that a particular feature, structure, function, or characteristic described in connection with the implementation is included in at least one implementation of the disclosure. The appearances of the phrase “in an implementation,” “in at least one implementation,” “in one implementation,” or “some implementations” in various places throughout this specification are not necessarily referring to the same implementation of the disclosure. Furthermore, the particular features, structures,functions, or characteristics may be combined in any suitable manner in one or more implementations. For example, a first implementation may be combined with a second implementation anywhere the particular features, structures, functions, or characteristics associated with the two implementations are not mutually exclusive.

[0017] Here, terms “coupled” and “connected,” along with their derivatives, may be used to describe functional or structural relationships between components. These terms are not intended as synonyms for each other. Rather, in at least one implementation, “connected” may be used to indicate that two or more elements are in direct physical, optical, or electrical contact with each other. Here, “coupled” may be used to indicate that two or more elements are in either direct or indirect (with other intervening elements between them) physical, electrical or in magnetic contact with each other, and / or that the two or more elements cooperate or interact with each other (e.g., as in a cause an effect relationship). Here, “coupled” may also generally refer to direct attachment of one electronic component to another. An electric or magnetic field may couple one component to another, where the field is controlled by one component to influence the other in some manner.

[0018] Here, “over,” “under,” “between,” and “on” may generally refer to a relative position of one component or material with respect to other components or materials where such physical relationships are noteworthy. Unless these terms are modified with “direct” or “directly,” one or more intervening components or materials may be present. Similar distinctions are to be made in the context of component assemblies. As used throughout this description, and in the claims, a list of items joined by “at least one of’ or “one or more of’ can mean any combination of the listed terms.

[0019] Here, “substantially,” “close,” “approximately,” “near,” and “about,” generally refer to being within + / - 10% of a target value. For example, unless otherwise specified in explicit context of their use, terms “substantially equal,” “about equal” and “approximately equal” mean that there is no more than incidental variation between among things so described. In at least one implementation, such variation is typically no more than + / -10% of a target value.

[0020] Here, “semiconductor process tool” may generally refer to an apparatus comprising a process chamber. In at least one implementation, a semiconductor process tool may comprise antechambers such as load lock for transferring semiconductor wafer into the process chamber. In at least one implementation, a semiconductor process tool may comprise a process cooling system to cool the walls of the process chamber, for example.

[0021] Here, “process chamber” may generally refer to a high vacuum chamber (e.g., operable to hold a pressure of 20 torr or less), component of a semiconductor fabrication tool. In at least one implementation, process module may generally house the tools such as a showerhead assembly and a wafer pedestal for performing a semiconductor fabrication processes on a substrate. In at least one implementation, substrate may be a semiconductor wafer, for example, held within the process module. In at least one implementation, process performed on the substrate may be a thin film deposition performed as a physical deposition process such as a metal film evaporation process, a sputtering process, etc. In at least one implementation, other thin film fabrication processes include chemical vapor deposition (CVD) processes, atomic layer deposition (ALD) processes, PECVD deposition processes, etch processes, such as a reactive ion etch (RIE), or plasma cleaning processes. In at least one implementation, a process module may comprise at least one wafer processing station into which the substrate is transferred for processing.

[0022] Here, “wall” may generally refer to an outer partition or surface of an enclosure for a chamber such as a process module. In at least one implementation, a wall may be a planar portion of an enclosure, joined to edges of other similar walls at angles such as orthogonal angles.

[0023] Here, “process cooling system” may generally refer to a system comprising one or more conduits that are in mechanical and thermal contact with one or more surfaces (e.g., of a process chamber) and a means to flow a coolant through the one or more conduits. In at least one implementation, one or more conduits may remove heat from the surfaces by convection through the coolant flowing through the conduit(s).

[0024] Here, “heat exchanger” may generally refer to a device accepting two or more fluid streams, comprising at least a first stream and a second stream, whereby the first stream has a higher temperature than the second stream. In at least one implementation, heat flows from the higher temperature stream to the lower temperature stream, enabling the second stream to increase its temperature while the first stream decreases in temperature during the residence time within the heat exchanger.

[0025] Here, “co-current” may generally refer to a flow configuration within a heat exchanger, whereby two streams comprising a first stream having a higher temperature and a second stream having a lower temperature, flow in the same direction. Such a configuration may be compared to a countercurrent flow, whereby the two streams flow in opposite directions. In at least one implementation, in a co-current flow configuration, a hot stream and a cold stream may enter a heat exchanger on a first side and exit the heat exchanger on asecond side. In at least one implementation, both streams exit at temperatures that are between the temperature of the first stream and the temperature of the second stream.

[0026] Here, “countercurrent” may generally refer to a flow configuration within a heat exchanger, whereby two streams comprising a first stream having a higher temperature and a second stream having a lower temperature, flow in opposite directions. In at least one implementation, a first steam enters a first channel of a heat exchanger on a first side and a second stream enters a second channel of the heat exchanger in an opposing direction. As the two flows are opposed, each stream may exit the heat exchanger at temperatures close to the entrance temperatures of the opposing stream, in accordance with at least one implementation.

[0027] Here, “process cooling water” may generally refer to water employed as a coolant to circulate within a process cooling system. Process cooling water may be abbreviated as PCW.

[0028] Here, “cold process cooling water” may generally refer to a temperature of process cooling water prior to preconditioning the process cooling water by a heat exchanger. Cold is a relative term, distinguishing a cooler PCW temperature from a warmer or hotter temperature. Cold may refer to the temperature of process cooling water prior to preconditioning, for example, the temperature of the process cooling water upon entering the process cooling system. A “cold” PCW temperature may be a “room” temperature (e.g., 15°C - 25°C), whereas a “hot” PCW temperature may refer to temperatures above 60°C.

[0029] Here, “preconditioned process cooling water” may generally refer to changing the temperature of process cooling water entering a process cooling system. For example, cold process cooling water may be preconditioned by passing it through a heat exchanger, where process cooling water is warmed by flow through a heat exchanger. In at least one implementation, heat exchanger may act to precondition the process cooling water by altering its temperature from “cold” (e.g., 15°- 25°C) to “warm” and “hot” temperatures between 60°C and 90°C. Cold, warm and hot are relative terms.

[0030] Here, “process cooling water supply” may generally refer to a source of process cooling water. In at least one implementation, a process cooling water supply may comprise a manifold.

[0031] Here, “process cooling water return” may generally refer to a drain or return manifold to which spent process cooling water flows. In at least one implementation, return may direct spent process cooling water to a reservoir where the spent process cooling water may be renewed by chilling.

[0032] Here, “upstream” may generally refer to the relative positions of two or more components of the process cooling system relative to the direction of process cooling water flowing in the process cooling system, according to at least one implementation. “Upstream” may mean that a first component is closer to the process cooling water supply than a second component. For example, the proportional valve may be upstream of the heat exchanger, whereby the heat exchanger is closer to the return than the proportional valve.

[0033] Here, “downstream” may generally refer to the relative positions of two or more components of the process cooling system relative to the direction of process cooling water flowing in the process cooling system, according to at least one implementation.“Downstream” may mean that a first component is closer to the process cooling water return than a second component. For example, in at least one implementation, the proportional valve may be downstream of the heat exchanger, whereby the heat exchanger is closer to the supply than the proportional valve.

[0034] Here, “conduit” may generally refer to tubing that conveys flow of process cooling water. In at least one implementation, a conduit may comprise copper or steel tubing.

[0035] Here, “proportional valve” may generally refer to a valve that has a variable gate or passage. In at least one implementation, a proportional valve may be continuously adjusted between the states of open and closed to regulate flow.

[0036] Here, “regulating” may generally refer to adjustment of a proportional valve to control the flow rate of process cooling water flowing through the proportional valve.

[0037] Here, “directional valve” may generally refer to a valve that has a binary gate or passage. In at least one implementation, a directional valve may have two states, open or closed, with no intermediate state.

[0038] Here, “two-way proportional valve” may generally refer to a proportional valve that has two ports.

[0039] Here, “four-way proportional valve” may generally refer to a proportional valve that has four ports.

[0040] Here, “water return conduit” may generally refer to a conduit coupled to a process cooling water return.

[0041] Here, “water supply conduit” may generally refer to a conduit coupled to a process cooling water supply.

[0042] Fig. 1 illustrates a block diagram of process cooling system 100, in accordance with at least one implementation. In at least one implementation, process cooling system 100 comprises process chamber 102, process cooling water supply 104 and process cooling waterreturn 106. In at least one implementation, process cooling system 100 further comprises proportional valve 108 and heat exchanger 110. In at least one implementation, heat exchanger 110 is downstream of proportional valve 108. In at least one implementation, process cooling system 100 comprises a cooling circuit comprising conduit 112, conduit 114, and conduit 116. In at least one implementation, conduits 112-116 comprise copper or steel tubing (e.g., 6 mm diameter or larger).

[0043] In at least one implementation, conduit 112 couples process water supply 104 to proportional valve 108. In at least one implementation, proportional valve 108 and heat exchanger 110 may be interconnected by conduit 114. In at least one implementation, conduit 116 may be a loop that delivers process cooling water to chamber 102.

[0044] In at least one implementation, conduit 116 may be in mechanical and thermal contact with one or more portions, including outer and / or inner surfaces, of process chamber 102. In at least one implementation, conduit 116 comprises a segment of copper tubing formed in a loop that contacts surfaces of chamber 102, where cooling of those surfaces may remove excess heat more efficiently than natural air convective transfer and radiative transfer. In at least one implementation, conduit 116 may be embedded within vertical walls or bottom plate of chamber 102. In at least one implementation, conduit 116 may be partially embedded within a groove cut along one or more walls of process chamber 102. In at least one implementation, conduit 116 may be encapsulated within an epoxy sheath to protect conduit 116 and to increase thermal contact between conduit 116 and surfaces of process chamber 102. In at least one implementation, encapsulation may also adhere conduit 116 to walls of process chamber 102.

[0045] In at least one implementation, heat exchanger 110 comprises a first inlet 118 in communication with a first outlet 120, and a second inlet 122 in communication with a second outlet 124. In at least one implementation, heat exchanger 110 may be configured as a co-current heat exchanger as shown, whereby a cold fluid (e.g., 10°C -25 °C) and hot fluid flow (e.g., 60°C- 90°C) in the same direction. While heat exchanger 110 may be configured as a countercurrent heat exchanger in at least one implementation, a co-current configuration may be employed. In at least one implementation, conduit 116 comprises a first end and a second end coupled to a first inlet 118 and a first outlet 120, respectively, of heat exchanger 110. In at least one implementation, conduit 112 is coupled to a second inlet 122 of heat exchanger 110. In at least one implementation, conduit 112 delivers cold process cooling water from process cooling water supply 104 to inlet 122 of heat exchanger 110. In at least one implementation, conduit 116 may be operable to deliver heated process cooling water toinlet 118 of heat exchanger 110. In at least one implementation during operation, cold process heating water and heated process cooling water flow to outlets 120 and 124, respectively. During residency within heat exchanger 110, heated process cooling water flow transfers heat to cold process water cooling water flow. Heat exchange may raise temperature of cold process cooling water (PCW) at outlet 120 to a temperature intermediate between the inlet temperatures of the hot and cold flows. In at least one implementation, heat transfer within heat exchanger 110 may also lower temperature of heated process cooling water at outlet 124 to a similar intermediate temperature. For example, exit flow temperatures may be 30°C to 50°C.

[0046] In at least one implementation, conduit 112 may pass through process chamber components 126, collectively represented by the stippled box. In at least one implementation, process chamber components 126 may comprise pedestals, showerheads, and other process components within process chamber 102. In at least one implementation, cold process cooling water flowing within conduit 112 may be warmed to as it passes through process chamber components 126.

[0047] In at least one implementation, process cooling water flowing into conduit 116 may be conditioned by heat exchanger 110 to mitigate thermal shock to portions of conduit 116 in mechanical and thermal contact with surfaces of chamber 102. For example, hot walls of chamber 102 may raise temperatures of contacting portions of conduit 116 well above 100°C. Unconditioned cold process water flow entering these heated portions of conduit 116 may damage tubing walls of conduit 116 by thermal shock engendered by the cold water encountering the hot tubing wall.

[0048] Without preconditioning by heat exchanger 110, conduit 116 may be damaged by sudden contraction of hot tubing wall in sudden contact by cold process cooling water. Over time, tubing wall may fracture and split. In some cases, gaps may form between portions of conduit 116 and surfaces of process chamber 102. In at least one implementation, heat exchanger 110 may enable preconditioning of cold process cooling water to higher temperatures, mitigating thermal shock to tubing walls of conduit 116 that are in contact with surfaces of process chamber 102.

[0049] In at least one implementation, proportional valve 108 regulates flow of process cooling water flowing into heat exchanger 110. In at least one implementation, proportional valve 108 may be a two-way proportional valve. In at least one implementation, proportional valve 108 may enable variable adjustment of flow of cold process cooling water for optimization of heat extraction from heated surfaces of process chamber 102. Thus,temperatures of walls of process chamber 102 may be smoothly regulated by enabling continuously regulated flow of process cooling water into the cooling loop of conduit 116. In process cooling schemes, a directional valve may be employed to pulse process cooling water to surfaces of process chamber 102, resulting in less steady temperature regulation. In addition, pulsed flow enables large temperature excursions of tubing walls of conduit 116, permitting potential damage by cold process cooling water periodically contacting hot tubing walls. In addition to breakage of the tubing, detachment of conduit 116 from process chamber 102 may occur.

[0050] In at least one implementation, heated process cooling water in conduit 116 flows into heat exchanger 110 and is tempered by co-current flow heat exchange with cold process cooling water. In at least one implementation, tempered heated process cooling water may exit heat exchanger 110 through outlet 124, and flow through conduit 128 to process cooling water return 106. In at least one implementation, process cooling water return 106 delivers spent process cooling water to an external heat exchanger (not shown) to circulate back to process cooling water supply 104.

[0051] Fig. 2 illustrates a block diagram of process cooling system 200, in accordance with at least one implementation. In at least one implementation, process cooling system 200 comprises process chamber 202, process cooling water supply 204 and process cooling water return 206. In at least one implementation, process cooling system 200 further comprises proportional valve 208 in line with heat exchanger 210. In at least one implementation, heat exchanger 210 is upstream of proportional valve 208. In at least one implementation, proportional valve 208 may be a four-way proportional valve. In at least one implementation process cooling system 200 comprises a cooling circuit comprising conduit 212, conduit 214 and conduit 216. In at least one implementation, conduits 212-216 comprise copper or steel tubing (e.g., 6 mm diameter or larger). In at least one implementation, conduit 212 may be coupled to process cooling water supply 204 and may deliver cold process water to heat exchanger 210.

[0052] In at least one implementation, conduit 216 may be in mechanical and thermal contact with one or more portions of process chamber 202. In at least one implementation, conduit 216 comprises a segment of tubing (e.g., copper or steel) formed into a loop that is in mechanical and thermal contact with outer and / or inner surfaces of walls of process chamber 202. In at least one implementation, conduit 216 may be encapsulated by an epoxy sheath and adhered to walls of process chamber 202.

[0053] In at least one implementation, conduit 216 may be formed into a loop that has a first end coupled to port 218 of proportional valve 208 and a second end coupled to inlet 220 of heat exchanger 210. In at least one implementation, preconditioned (e.g., warm) process cooling water may be directed to flow from port 218 to process chamber 202. In at least one implementation, rate of flow or preconditioned process cooling water may be regulated by proportional valve 208. In at least one implementation, heated process cooling water flowing from process chamber 202 may enter heat exchanger 210 at inlet 220. In at least one implementation, cold process cooling water may enter heat exchanger 210 via conduit 212 and inlet 222. In at least one implementation, heat exchanger 210 may be configured as a cocurrent heat exchanger, whereby cold flow and hot flow are in the same direction. In at least one implementation, heat exchanged by the two flows enable warm process cooling water to exit heat exchanger 210 via outlets 224 and 226. In at least one implementation, preconditioned (e.g., warm) process cooling water flows into port 228 and port 230 of proportional valve 208 from outlets 224 and 226, respectively. In at least one implementation, within proportional valve 208, preconditioned process cooling water may be directed to flow out of port 218 and out of port 232, returning preconditioned cooling water to process chamber 202. This enables spent process cooling water to flow to process cooling water return 206 via conduit 234, respectively, in accordance with at least one implementation.

[0054] Fig. 3 illustrates a block diagram of process cooling system 300, in accordance with at least one implementation. In at least one implementation, process cooling system 300 comprises process chamber 302, process cooling water supply 304 and process cooling water return 306. In at least one implementation, process cooling system 300 further comprises proportional valve 308 in line with heat exchanger 310. In at least one implementation, proportional valve 308 may be upstream of heat exchanger 310. In at least one implementation, proportional valve 308 may be a four- way proportional valve. In at least one implementation, proportional valve 308 may be upstream of heat exchanger 310. In at least one implementation process cooling system 300 comprises a cooling circuit comprising conduit 312, conduit 314, conduit 316, and conduit 318. In at least one implementation, conduits 312-318 comprise copper or steel tubing (e.g., 6 mm diameter or larger). In at least one implementation, conduit 312 may be coupled to process cooling water supply 304 and may deliver cold process water to heat exchanger 310.

[0055] In at least one implementation, conduit 316 may be in mechanical and thermal contact with one or more portions of process chamber 302. In at least one implementation, conduit 316 comprises a segment of tubing (e.g., copper or steel) formed into a loop that maybe in mechanical and thermal contact with outer and / or inner surfaces of walls of process chamber 302. In at least one implementation, conduit 316 may be encapsulated by an epoxy sheath and adhered to walls of process chamber 302.

[0056] In at least one implementation, conduit 312 may be coupled to process cooling water supply 304 and may deliver cold process cooling water to inlet 319 of heat exchanger 310. In at least one implementation, cold process cooling water may be preconditioned (warmed) by heat exchanger 310 and flows into port 320 of proportional valve 308 via conduit 318. In at least one implementation, conduit 316 may be coupled to port 322 of proportional valve 308, delivering heated process cooling water to proportional valve 308 after having contacted heated surfaces of process chamber 302. In at least one implementation, heated process cooling water entering proportional valve 308 through port 322 may mix with warmed process cooling water entering proportional valve 308 through port 320 that may exit proportional valve 308 as heated process cooling water via port 324 and port 326 of proportional valve 308. In at least one implementation, heated process cooling water may be directed to reenter heat exchanger 310 via inlet 328. In at least one implementation, preconditioned (warm) process cooling water exits heat exchanger 310 via both outlets 332 and 334 after exchanging heat within heat exchanger 310. In at least one implementation, outlet 332 returns preconditioned (warm) process cooling water towards process chamber 302. In at least one implementation, outlet 334 directs warm process cooling water to mix with heated process cooling water in proportional valve 308 as described above. In at least one implementation, spent process cooling water may exit port 326 of proportional valve 308 to process cooling water return 306.

[0057] Fig. 4 illustrates a block diagram of process cooling system 400, in accordance with at least one implementation. In at least one implementation, process cooling system 400 comprises process chamber 402, process cooling water supply 404 and process cooling water return 406. In at least one implementation, process cooling system 400 further comprises proportional valve 408. In at least one implementation, proportional valve 408 may be a fourway proportional valve. In at least one implementation, a heat exchanger (e.g., heat exchanger 310) may be omitted. In at least one implementation process cooling system 400 comprises a cooling circuit comprising conduit 410, conduit 412, and conduit 414. In at least one implementation, conduits 410-414 comprise copper or steel tubing (e.g., 6 mm diameter or larger). In at least one implementation, conduit 410 is coupled to process cooling water supply 404 and may deliver cold process water to proportional valve 408.

[0058] In at least one implementation, conduit 412 may be in mechanical and thermal contact with one or more portions of process chamber 402. In at least one implementation, conduit 412 comprises a segment of tubing (e.g., copper or steel) formed into a loop that is in mechanical and thermal contact with outer and / or inner surfaces of walls of process chamber 402. In at least one implementation, conduit 412 may be encapsulated by an epoxy sheath and adhered to walls of process chamber 402.

[0059] In at least one implementation, conduit 412 may be formed into a loop that has a first end coupled to port 416 of proportional valve 408 and a second end coupled to port 418 of proportional valve 408. In at least one implementation, preconditioned (e.g., warm) process cooling water may be directed to flow from port 416 to process chamber 402. In at least one implementation, rate of flow or preconditioned process cooling water may be regulated by proportional valve 408.

[0060] In at least one implementation, proportional valve 408 may provide mixing of cold and hot streams to precondition cold process cooling water in lieu of a heat exchanger. In at least one implementation, conduit 410 delivers cold process cooling water to port 420 of proportional valve 408. In at least one implementation, heated process cooling water may enter port 418 of proportional valve 408 and mix with cold process cooling water. In at least one implementation, mixing process may precondition the process cooling water to more moderate temperatures. In at least one implementation, preconditioned process cooling water may be directed to flow out of port 416, returning preconditioned process cooling water to process chamber 402, and out of port 422. In at least one implementation, port 416 may deliver spent process cooling water to process cooling water return 406 via conduit 414.

[0061] Fig. 5 illustrates a block diagram of process cooling system 500, in accordance with at least one implementation. In at least one implementation, process cooling system 500 comprises process chamber 502, process cooling water supply 504, and process cooing water return 506. In at least one implementation, process cooling system 500 further comprises proportional valve 508 and heat exchanger 510. In at least one implementation, proportional valve 508 may be upstream of heat exchanger 510. In at least one implementation, proportional valve 508 may be a two-way proportional valve. In at least one implementation, heat exchanger 510 may be configured for co-current flow. In at least one implementation, process cooling system 500 comprises a cooling circuit comprising conduit 512, conduit 514 and conduit 516. In at least one implementation, conduits 512-516 comprise copper or steel tubing (e.g., 6 mm diameter or larger). In at least one implementation, conduit 512 may becoupled to process cooling water supply 504 and may deliver cold process water to heat exchanger 510.

[0062] In at least one implementation, conduit 516 may be in mechanical and thermal contact with one or more portions of process chamber 502. In at least one implementation, conduit 516 comprises a segment of tubing (e.g., copper or steel) formed into a loop that may be in mechanical and thermal contact with outer and / or inner surfaces of walls of process chamber 502. In at least one implementation, conduit 516 may be encapsulated by an epoxy sheath and adhered to walls of process chamber 502.

[0063] In at least one implementation, conduit 516 may be formed into a loop that has a first end coupled to an outlet of proportional valve 508 and a second end coupled to inlet 518 of heat exchanger 510. In at least one implementation, preconditioned (e.g., warm) process cooling water may be directed to flow from proportional valve 508 to process chamber 502. In at least one implementation, rate of flow or preconditioned process cooling water may be regulated by proportional valve 508. In at least one implementation, heated process cooling water flowing from process chamber 502 may enter heat exchanger 510 at inlet 518. In at least one implementation, cold process cooling water may enter heat exchanger 510 via conduit 512 and inlet 520. In at least one implementation, heat exchanger 510 may be configured as a co-current heat exchanger, whereby cold flow and hot flow are in the same direction. In at least one implementation, heat exchanged by the two flows enable warm process cooling water to exit heat exchanger 510 via outlets 522 and 524. In at least one implementation, preconditioned (e.g., warm) process cooling water flows into proportional valve 508 via conduit 514.

[0064] In at least one implementation, directional valve 526 may be in parallel with proportional valve 508. In at least one implementation, directional valve 526 may enable bypass of proportional valve 508. In at least one implementation, directional valve 526 may be configured to pulse process cooling water to conduit 516. In at least one implementation, spent process cooling water exits heat exchanger 510 through outlet 524, and is delivered to process cooling water return 506 via conduit 528.

[0065] Fig. 6 illustrates a flow chart 600 of a method to operate a process cooling system, in accordance with at least one implementation. In at least one implementation, various operations of flow chart 600 may be controlled or initiated by software, hardware, or a combination of them.

[0066] In at least one implementation, at operation 602, a process cooling system is activated, and cold process cooling water is flowed into a first inlet of a heat exchanger (e.g.,inlet 520 of heat exchanger 510) from a process cooling water (PCW) supply (e.g., PCW supply 504). In at least one implementation, at operation 604, heated process cooling water is flowed into a second inlet of the heat exchanger (e.g., inlet 518 of heat exchanger 510).

[0067] In at least one implementation, at operation 606, cold process cooling water may be preconditioned by co-current heat transfer from heated process cooling water to cold process cooling water within the heat exchanger. In at least one implementation, cold process cooling water may have a temperature of 15°C to 25°C. In at least one implementation, heated process cooling water may have a temperature of 60°C to 90°C. In at least one implementation, heated process cooling water has a temperate greater than the temperature of cold process cooling water. In at least implementation, preconditioned process cooling water may have a temperature of 30°C to 50°C.

[0068] In at least one implementation, at operation 608, preconditioned process cooling water may exit via an outlet of heat exchanger (e.g., outlet 522) to a process chamber (e.g., process chamber 502). In at least one implementation, preconditioned process cooling water passes through a proportional valve (e.g., proportional valve 508). In at least one implementation, preconditioned process cooling water may mitigate damage to conduit conveying process cooling water along surfaces of the process chamber by reducing thermal shock that may be present in pulsed delivery systems.

[0069] In at least one implementation, at operation 610, the proportional valve may be adjusted to regulate flow of preconditioned process cooling water. In at least one implementation, regulation of flow may enable temperature regulation of surfaces of process chamber 502 without temperature excursions that may be encountered by pulsed flow.

[0070] The following examples are provided that illustrate at least one implementation. An example can be combined with any other example. As such, at least one implementation can be combined with at least another implementation without changing the scope of the disclosure.

[0071] Example 1 is a process cooling system, comprising a heat exchanger comprising a first inlet, a first outlet, a second inlet, and a second outlet; a process cooling water supply coupled to the first inlet of the heat exchanger; a proportional valve coupled to the first outlet of the heat exchanger; a conduit coupled to a process chamber, wherein a first end of the conduit is coupled to the proportional valve and a second end of the conduit is coupled to the second inlet of the heat exchanger; and a process cooling water return coupled to the second outlet of the heat exchanger.

[0072] Example 2 includes all features of example 1, wherein the proportional valve is a two-way proportional valve.

[0073] Example 3 includes all features of example 1, wherein the proportional valve is a four-way proportional valve.

[0074] Example 4 includes all features of example 1, further comprising a directional valve in parallel with the proportional valve, wherein the directional valve is coupled to the first outlet of the heat exchanger and to the first end of the conduit.

[0075] Example 5 includes all features of example 1, wherein the proportional valve is upstream of the heat exchanger.

[0076] Example 6 includes all features of example 1, wherein the proportional valve is downstream of the heat exchanger.

[0077] Example 7 includes all features of example 1, wherein the process cooling water supply is coupled to the first inlet of the heat exchanger.

[0078] Example 8 includes all features of example 7, wherein the conduit is coupled to the second inlet of the heat exchanger.

[0079] Example 9 includes all features of example 1, wherein the heat exchanger is configured as a co-current heat exchanger.

[0080] Example 10 includes all features of example 1, wherein the heat exchanger is configured as a countercurrent heat exchanger.

[0081] Example 11 is a semiconductor process tool, comprising: a process chamber comprising a cooling system, wherein the cooling system comprises: a heat exchanger comprising a first inlet, a first outlet, a second inlet and a second outlet; a process cooling water supply coupled to the first inlet of the heat exchanger; a proportional valve coupled to the first outlet of the heat exchanger; a conduit coupled with a wall of the process chamber, wherein a first end of the conduit is coupled to the proportional valve and a second end of the conduit is coupled to the second inlet of the heat exchanger; and a process cooling water return coupled to the second outlet of the heat exchanger; a water supply conduit coupled to the process cooling water supply; and a water return conduit coupled to the process cooling water return.

[0082] Example 12 includes all features of example 11, wherein the conduit is a first conduit, the wall is a first wall, the proportional valve is a first proportional valve, the heat exchanger is a first heat exchanger, and wherein a second conduit is coupled to a second wall of the process chamber.

[0083] Example 13 includes all features of example 12, wherein a directional valve is in parallel with the proportional valve.

[0084] Example 14 is A method, comprising activating a process cooling system, wherein the process cooling system comprises a heat exchanger comprising a first inlet, a first outlet, a second inlet and a second outlet; a process cooling water supply coupled to the first inlet of the heat exchanger; a process cooling water return coupled to the first outlet o the heat exchanger; a proportional valve coupled to the second outlet of the heat exchanger; and a conduit coupled to a process chamber, wherein a first end of the conduit is coupled to the proportional valve, and wherein a second end of the conduit is coupled to the second inlet of the heat exchanger; flowing a cold process cooling water into the first inlet of the heat exchanger; flowing a heated process cooling water into the second inlet of the heat exchanger; preconditioning the cold process cooling water to produce a preconditioned process cooling water; flowing the preconditioned process cooling water to the conduit; and regulating a flow of the preconditioned process cooling water.

[0085] Example 15 includes all features of example 14, wherein flowing the cold process cooling water into the first inlet of the heat exchanger comprises flowing the cold process cooling water at a first temperature.

[0086] Example 16 includes all features of example 15, wherein flowing the heated process cooling water into the second inlet of the heat exchanger comprises flowing the heated process cooling water at a second temperature, and wherein the second temperature is greater than the first temperature.

[0087] Example 17 includes all features of example 16, wherein preconditioning the cold process cooling water comprises flowing the preconditioned process cooling water out of the heat exchanger at a third temperature, and wherein the third temperature is between the first temperature and the second temperature.

[0088] Example 18 includes all features of example 17, wherein flowing the preconditioned process cooling water into the conduit comprises flowing the preconditioned process cooling water out of the heat exchanger and passing the preconditioned process cooling water through the proportional valve.

[0089] Example 19 includes all features of example 14, wherein regulating the flow of the preconditioned process cooling water comprises adjusting the proportional valve.

[0090] Example 20 includes all features of example 19, wherein adjusting the proportional valve comprises adjusting the flow of the preconditioned process cooling water to regulate a temperature of a surface of the process chamber.

[0091] Example 21 includes all features of example 20, wherein preconditioning the cold process cooling water comprises mixing the cold process cooling water with the heated process cooling water within the proportional valve, and wherein the proportional valve is a four-way proportional valve.

[0092] Besides what is described herein, various modifications may be made to at least one implementation thereof without departing from their scope. Therefore, illustrations of at least one implementation herein should be construed as examples only, and not restrictive to the scope of the present disclosure.

Claims

CLAIMSWe claim:

1. A process cooling system, comprising: a heat exchanger comprising a first inlet, a first outlet, a second inlet, and a second outlet; a process cooling water supply coupled to the first inlet of the heat exchanger; a proportional valve coupled to the first outlet of the heat exchanger; a conduit coupled to a process chamber, wherein a first end of the conduit is coupled to the proportional valve and a second end of the conduit is coupled to the second inlet of the heat exchanger; and a process cooling water return coupled to the second outlet of the heat exchanger.

2. The process cooling system of claim 1, wherein the proportional valve is a two-way proportional valve.

3. The process cooling system of claim 1, wherein the proportional valve is a four-way proportional valve.

4. The process cooling system of claim 1, further comprising a directional valve in parallel with the proportional valve, wherein the directional valve is coupled to the first outlet of the heat exchanger and to the first end of the conduit.

5. The process cooling system of claim 1, wherein the proportional valve is upstream of the heat exchanger.

6. The process cooling system of claim 1, wherein the proportional valve is downstream of the heat exchanger.

7. The process cooling system of claim 1, wherein the process cooling water supply is coupled to the first inlet of the heat exchanger.

8. The process cooling system of claim 7, wherein the conduit is coupled to the second inlet of the heat exchanger.

9. The process cooling system of claim 1, wherein the heat exchanger is configured as a co-current heat exchanger.

10. The process cooling system of claim 1, wherein the heat exchanger is configured as a countercurrent heat exchanger.

11. A semiconductor process tool, comprising: a process chamber comprising a cooling system, wherein the cooling system comprises: a heat exchanger comprising a first inlet, a first outlet, a second inlet and a second outlet; a process cooling water supply coupled to the first inlet of the heat exchanger; a proportional valve coupled to the first outlet of the heat exchanger; a conduit coupled with a wall of the process chamber, wherein a first end of the conduit is coupled to the proportional valve and a second end of the conduit is coupled to the second inlet of the heat exchanger; and a process cooling water return coupled to the second outlet of the heat exchanger; a water supply conduit coupled to the process cooling water supply; and a water return conduit coupled to the process cooling water return.

12. The semiconductor process tool of claim 11, wherein the conduit is a first conduit, the wall is a first wall, the proportional valve is a first proportional valve, the heat exchanger is a first heat exchanger, and wherein a second conduit is coupled to a second wall of the process chamber.

13. The semiconductor process tool of claim 12, wherein a directional valve is in parallel with the proportional valve.

14. A method, comprising: activating a process cooling system, wherein the process cooling system comprises: a heat exchanger comprising a first inlet, a first outlet, a second inlet and a second outlet; a process cooling water supply coupled to the first inlet of the heat exchanger;a process cooling water return coupled to the first outlet o the heat exchanger; a proportional valve coupled to the second outlet of the heat exchanger; and a conduit coupled to a process chamber, wherein a first end of the conduit is coupled to the proportional valve, and wherein a second end of the conduit is coupled to the second inlet of the heat exchanger; flowing a cold process cooling water into the first inlet of the heat exchanger; flowing a heated process cooling water into the second inlet of the heat exchanger; preconditioning the cold process cooling water to produce a preconditioned process cooling water; flowing the preconditioned process cooling water to the conduit; and regulating a flow of the preconditioned process cooling water.

15. The method of claim 14, wherein flowing the cold process cooling water into the first inlet of the heat exchanger comprises flowing the cold process cooling water at a first temperature.

16. The method of claim 15, wherein flowing the heated process cooling water into the second inlet of the heat exchanger comprises flowing the heated process cooling water at a second temperature, and wherein the second temperature is greater than the first temperature.

17. The method of claim 16, wherein preconditioning the cold process cooling water comprises flowing the preconditioned process cooling water out of the heat exchanger at a third temperature, and wherein the third temperature is between the first temperature and the second temperature.

18. The method of claim 17, wherein flowing the preconditioned process cooling water into the conduit comprises flowing the preconditioned process cooling water out of the heat exchanger and passing the preconditioned process cooling water through the proportional valve.

19. The method of claim 14, wherein regulating the flow of the preconditioned process cooling water comprises adjusting the proportional valve.

20. The method of claim 19, wherein adjusting the proportional valve comprises adjusting the flow of the preconditioned process cooling water to regulate a temperature of a surface of the process chamber.

21. The method of claim 20, wherein preconditioning the cold process cooling water comprises mixing the cold process cooling water with the heated process cooling water within the proportional valve, and wherein the proportional valve is a four-way proportional valve.

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