US20170191685A1

US20170191685A1 - Self-sustained in-situ thermal control apparatus

Info

Publication number: US20170191685A1
Application number: US14/984,178
Authority: US
Inventors: Allan Ronne; Michael Tseng; Henry Wang
Original assignee: Lam Research Corp
Current assignee: Lam Research Corp
Priority date: 2015-12-30
Filing date: 2015-12-30
Publication date: 2017-07-06

Abstract

A thermal management system for a substrate processing tool located in a fabrication room includes a blower that draws air from the fabrication room and causes the air to flow through a process module of the substrate processing tool. Heat is transferred from the process module to the air and the air is exhausted from the process module. A heat exchanger receives the air exhausted from the process module, cools the air, and provides the cooled air to at least one of the fabrication room, a subfloor of the fabrication room, and the process module.

Description

FIELD

The present disclosure relates to substrate processing systems, and more particularly to thermal management systems and methods for substrate processing systems.

BACKGROUND

The background description provided here is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Substrate processing systems may be used to perform deposition, etching and/or other treatment of substrates such as semiconductor wafers. During processing, a substrate is arranged on a substrate support such as a pedestal in a processing chamber of the substrate processing system. Gas mixtures including one or more precursors are introduced into the processing chamber and plasma may be struck to activate chemical reactions.
During processing, heat is generated, which increases temperatures of various components of a substrate processing tool. The substrate processing tool draws in ambient air (e.g., cleanroom air in a fabrication room of a facility in which the substrate processing tool is located) to cool the heated components.
As shown in FIGS. 1A and 1B, an example facility 100 includes one or more fabrication rooms 104-1, 104-2, . . . , and 104-n, referred to collectively as fabrication rooms 104. Each of the rooms 104 includes one or more substrate processing tools 108-1, 108-2, . . . , and 108-m, referred to collectively as substrate processing tools 108. Each of the substrate processing tools 108 includes one or more process modules (not shown).
The substrate processing tools 108 draw in cool ambient air 112 from within the rooms 104 to cool heated components of the substrate processing tools 108. For example, the air 112 is drawn into enclosures corresponding to respective process modules of the substrate processing tools 108 (e.g., via ports, screens, vents, etc. arranged in respective enclosure surfaces of the substrate processing tools 108). Typically, the rooms 104 correspond to fabrication cleanrooms. Accordingly, the air 112 within the rooms 104 is filtered and controlled to minimize contaminants. Heat from the respective components of the substrate processing tools 108 is transferred to the air 112, which is heated accordingly. The heated air 116 is exhausted from the substrate processing tools 108 via respective conduits or ducts 120. For example, the exhausted heated air 116 is drawn through the conduits 120 by a thermal exhaust treatment system 124, which then routes the heated air 116 into the environment outside of the facility 100.

SUMMARY

A thermal management system for a substrate processing tool located in a fabrication room includes a blower that draws air from the fabrication room and causes the air to flow through a process module of the substrate processing tool. Heat is transferred from the process module to the air and the air is exhausted from the process module. A heat exchanger receives the air exhausted from the process module, cools the air, and provides the cooled air to at least one of the fabrication room, a subfloor of the fabrication room, and the process module.
A thermal management method for a substrate processing tool located in a fabrication room include drawing air from the fabrication room and causing the air to flow through a process module of the substrate processing tool to transfer heat from the process module to the air, exhausting the air from the process module, receiving the air exhausted from the process module, cooling the air, and providing the cooled air to at least one of the fabrication room, a subfloor of the fabrication room, and the process module.
Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims and the drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

FIG. 1A is an example fabrication room including one or more substrate processing tools;

FIG. 1B is an example facility including a plurality of fabrication rooms;

FIG. 2A is an example fabrication room including one or more substrate processing tools according to the principles of the present disclosure;

FIG. 2B is another example fabrication room including one or more substrate processing tools according to the principles of the present disclosure;

FIG. 2C is another example fabrication room including one or more substrate processing tools according to the principles of the present disclosure;

FIG. 2D is another example fabrication room including one or more substrate processing tools according to the principles of the present disclosure;

FIG. 3 is an example substrate processing tool according to the principles of the present disclosure;

FIG. 4A is an example thermal management system according to the principles of the present disclosure;

FIG. 4B is another example thermal management system according to the principles of the present disclosure;

FIG. 5A is an example thermal management assembly according to the principles of the present disclosure;

FIG. 5B is another example thermal management assembly according to the principles of the present disclosure; and

FIG. 6 is an example thermal management method according to the principles of the present disclosure.

In the drawings, reference numbers may be reused to identify similar and/or identical elements.

DETAILED DESCRIPTION

Substrate processing facilities typically use a centralized thermal exhaust treatment system to draw heated exhaust air from fabrication rooms. The thermal exhaust treatment system routes the heated exhaust air out of the facility and into the environment. Accordingly, cleanroom air inside the fabrication rooms is consumed (e.g., the cleanroom air is used to cool substrate processing tools and then removed from the fabrication rooms and the facility) and must be replaced. Because every substrate processing tool is serviced by the same thermal exhaust treatment system, the operation of each tool affects the overall performance and efficiency of the system. The location of each tool (e.g., the distance of the tool from the thermal exhaust treatment system) further affects performance and efficiency.
Thermal exhaust treatment systems and methods according to the present disclosure provide separate exhaust treatment systems for each process module of a substrate processing tool. For example, each process module is provided a respective blower and heat exchanger. Each blower draws the heated exhaust air from the respective process module and routes the exhaust air through the heat exchanger. The exhaust air flows through the heat exchanger to be cooled and the resulting cooled air is provided back into the fabrication room (or, in some examples, the cooled air may be provided back to the same process module). Accordingly, the cleanroom air is recycled and reused instead of being exhausted from the facility. For example only, the blower and/or heat exchanger for each process module may be located in a subfloor region below a floor of the fabrication room.
Respective flow rates and temperatures for each of the process modules may be individually monitored, controlled, and adjusted. Further, service and/or maintenance on one of the exhaust treatment systems does not require interruption of the operation of other process modules and their respective exhaust treatment systems.
Referring now to FIGS. 2A 2B, 2C, and 2D an example fabrication room 200 includes one or more substrate processing tools 204. For example, the room 200 corresponds to a fabrication room supplied with cleanroom air (i.e., air that is filtered and controlled to minimize contaminants). Although only one substrate processing tool 204 is shown, the fabrication room 200 may include two or more of the substrate processing tools 204. The substrate processing tool 204 includes one or more process modules 208, which may be enclosed within a chassis or other enclosure 210. Cool ambient air 212 is drawn into portions of the substrate processing tools 204 corresponding to the process modules 208 from within the room 200 to cool respective components of the process modules 208. For example only, the air 212 is drawn in through respective ports 214 (e.g., ducts, screens, vents, etc. arranged in respective surfaces of the enclosures 210) to be routed over various external surfaces and/or components of the process modules 208, through conduits or channels adjacent to external surfaces and/or components of the process modules 208, etc. Heat from the components of the process modules 208 is transferred to the air 212.
Heated air 216 is exhausted from the process modules 208 and drawn into respective conduits or ducts 220. For example, the heated air 216 is drawn into the conduits 120 by respective blowers or fans 224. The blowers 224 draw the heated air 216 through the conduits 120 and into respective heat exchangers 228, which cool the heated air 216. For example, the heat exchangers 228 may implement a cold fluid cooling system (e.g., including cooling water or other fluids) to draw out heat from the heated air 216. As shown, the blowers 224 and heat exchangers 228 are each located below a floor 232 of the room 200 in a subfloor compartment 236. However, in other implementations, the blowers 224 and/or the heat exchangers 228 may be located within the room 200. Further, although one blower 224 is shown for each of the process modules 208, two or more of the blowers 224 may be used. For example, one of the blowers 224 may be arranged upstream of the heat exchanger 228 while another blower 224 is arranged downstream of the heat exchanger 228.
As shown in FIGS. 2A and 2C, cooled air 240 is routed back into the fabrication room 200. Accordingly, the same cleanroom air that was drawn into process modules 208 is heated, cooled, and then returned to the fabrication room 200. Although shown being returned to the ambient cleanroom air of the fabrication room 200, the cooled air 240 may be routed back into the process modules 208 in some embodiments to provide additional cooling. In example embodiments shown in FIGS. 2B and 2D, the cooled air 240 is routed into the subfloor compartment 236.
A flow rate of the heated air 216 and the cooled air 240 may be controlled by adjusting respective speeds of the blowers 224. In some embodiments, adjustable dampers 244 (e.g., gate valve dampers, butterfly valve dampers, etc.) may be provided to further control flow rates. A temperature of the cooled air 240 may be controlled by controlling a temperature and flow rate of the cold fluid in the heat exchangers 228. Accordingly, flow rates and temperatures of air provided to the respective process modules 208 can be individually monitored and controlled.
For example only, each of the blowers 224 (and/or the heat exchangers 228) receive power from the respective substrate processing tools 204. For example, the blowers 224 receive DC power from the substrate processing tools 204. Each of the blowers 224 may be configured to be powered on whenever the substrate processing tools 204 are powered on, only when a respective process module 208 is powered on, or may include respective switches to be selectively powered on. In some embodiments, the substrate processing tools 204 may be configured to selectively power on and adjust flow rates of the blowers 224 (and/or to selectively adjust the dampers 244) based on process steps being performed by the process modules 208.
Referring now to FIG. 2B, two or more process modules 208 may share one or more heat exchangers 228 and blowers 224. Although only one heat exchanger 228 is shown, two or more of the heat exchangers 228 may be provided in series. The heated air 216 from the respective conduits 220 is provided to an exhaust manifold 248, which routes the heated air 216 into the heat exchanger 228. In this embodiment, one or more of the blowers 224 may implement a variable frequency driver 252 to maintain a constant pressure and flow rate.
Referring now to FIG. 3 and with continued reference to FIGS. 2A and 2B, a top-down view of an example substrate processing tool 300 according to the principles of the present disclosure is shown. The substrate processing tool 300 includes a plurality of process modules 304. For example only, each of the process modules 304 may be configured to perform one or more respective processes on a substrate. Substrates to be processed are loaded into the substrate process tool 300 via ports of a loading station 308 and then transferred into one or more of the process modules 304. For example, a substrate may be loaded into each of the process modules 304 in succession.
Each of the process modules 304 draws in cleanroom ambient air 312 and exhausts the heated air through respective conduits 316, downward through floor 320, and into respective heat exchangers (e.g., the heat exchangers 228) as described above in FIG. 2. Although shown arranged on same respective sides of the process modules 304, the conduits 316 may be arranged on an opposite respective side of a process module 304 as shown at 318.
A user interface module 324 (e.g., an interface including output devices such as a display, LEDs, speakers, etc. and input devices such as a buttons, switches, knobs, dials, touchscreen, etc.) may be provided for controlling various functions of the tool 300. For example, a user may use the user interface module 324 to control operation of the blowers 224 and the heat exchangers 228. For example, the user interface module 324 may be used to selectively power the blowers 224 and the heat exchangers 228 on and off (e.g., individually and/or collectively), open and close the dampers 244, set desired respective setpoint flow rates and temperatures for the blowers 224 and the heat exchangers 228, etc., and may further be used to monitor flow rates and temperatures.
Referring now to FIGS. 4A and 4B, an example flow schematic of a thermal management system 400 that draws in cool cleanroom air and exhausts heated cleanroom air to cool components of respective process modules 404. In FIG. 4A, each of the process modules 404 exhausts the heated cleanroom air through dampers 408 (e.g., including gate valves or butterfly valves) and openings in floor 412 to heat exchangers 416. The heat exchangers 416 cool the air by, for example, flowing cold water or another fluid drawn in through inlets 420 and out through outlets 424. Heat from the air is transferred from the heated air to the fluid flowing through the heat exchangers 416, and the cooled air is drawn by blowers 428 to be returned to the environment above the floor 412 and/or to the process modules 404. In some examples, sensors 432 and 436 (e.g., temperature sensors, such as thermocouples, pressure sensors, flow sensors, etc.) monitor flow rates and temperatures of the heated air flowing out of the process modules 404 and out of the cooled air flowing out of the blowers 428, respectively. Signals indicative of the monitored flow rates and temperatures are provided to a user interface module 440.
In FIG. 4B, each of the process modules 404 exhausts the heated cleanroom air through dampers 408 (e.g., including gate valves or butterfly valves) and openings in floor 412 to manifold 444. The manifold 444 routes the heated air 216 into one or more heat exchangers 448 (e.g., as shown, two heat exchangers 448 connected in series). In this embodiment, one or more of the blowers 428 may implement a variable frequency driver 452 to maintain a constant pressure and flow rate. For example, the user interface module 440 may control the variable frequency driver 452 based on the monitored flowrates, a monitored pressure within the manifold 444, etc.
Referring now to FIGS. 5A and 5B, an example thermal management assembly 500 is arranged in a subfloor region 504 of a fabrication room 508. In FIG. 5A, the assembly 500 is shown in a horizontal arrangement. In FIG. 5B, the assembly 500 is shown in a vertical arrangement. Heated exhaust air is drawn downward through a floor 512 via a conduit 516. The conduit 516 and/or the floor 512 may include a screen or filter 520 at an interface between the fabrication room 508 and the subfloor region 504.
The heated exhaust air is routed to a heat exchanger 524 to cool the heated exhaust air. A first blower 528 is arranged to draw the heated exhaust air from the conduit 516 into the heat exchanger 524. A second blower 532 is arranged to draw cooled air into a conduit 536 to be provided to the fabrication room 508. Adaptors 540 may be provided to connect the conduit 516 to the first blower 528, to connect the first blower 528 to the heat exchanger 524, to connect the heat exchanger 524 to the second blower 532, and to connect the second blower 532 to the conduit 536. At least one sensor 545 may be arranged to sense parameters of the air at various locations within the assembly 500 (e.g., temperature, pressure, flow rate, etc.). For example only, the sensor 545 may correspond to a thermocouple. Although shown on opposing sides of the heat exchanger 524 (e.g., on an upstream side and a downstream side of the heat exchanger 524, respectively), in some examples the first blower 528 and the second blower 532 may each be arranged on a same side of the heat exchanger 524. In one example, the first blower 528 and the second blower 532 are both arranged on the upstream side of the heat exchanger 524. In another example, the first blower 528 and the second blower 532 are both arranged on the downstream side of the heat exchanger 524.
Referring now to FIG. 6, an example thermal management method 600 begins at 604. At 608, the method 600 begins to perform a processing step on a substrate. For example, the method 600 performs the processing step within a process module of a substrate processing tool. At 612, the method 600 determines whether to power on, or continue powering on, a thermal management system (e.g., a blower and/or a heat exchanger). For example, the method 600 may power on the thermal management system in response to the substrate processing tool being turned on, in response to a processing step being initiated, in response to a temperature of the process module reaching a threshold, etc. If true, the method 600 continues to 616. If false, the method continues to 620. At 620, the method 600 determines whether the processing step is complete. If true, the method 600 ends at 624. If false, the method 600 continues to 612.
At 616, the method 600 determines whether to adjust one or more components of the thermal management system based on respective monitored parameters. For example, adjustable components include, but are not limited to, dampers, heat exchangers, and blowers. The respective monitored parameters include, but are not limited to, a temperature of heated exhaust air, a temperature of cooled air returned from the thermal management system, a flow rate of the heated exhaust air out of the substrate processing tool, a flow rate of the cooled air, a pressure within a manifold, etc. At 628, the method 600 selectively adjusts the one or more components of the thermal management system and continues to 620.
The foregoing description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure. Further, although each of the embodiments is described above as having certain features, any one or more of those features described with respect to any embodiment of the disclosure can be implemented in and/or combined with features of any of the other embodiments, even if that combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and permutations of one or more embodiments with one another remain within the scope of this disclosure.
Spatial and functional relationships between elements (for example, between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including “connected,” “engaged,” “coupled,” “adjacent,” “next to,” “on top of,” “above,” “below,” and “disposed.” Unless explicitly described as being “direct,” when a relationship between first and second elements is described in the above disclosure, that relationship can be a direct relationship where no other intervening elements are present between the first and second elements, but can also be an indirect relationship where one or more intervening elements are present (either spatially or functionally) between the first and second elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”
In some implementations, a controller is part of a system, which may be part of the above-described examples. Such systems can comprise semiconductor processing equipment, including a processing tool or tools, chamber or chambers, a platform or platforms for processing, and/or specific processing components (a wafer pedestal, a gas flow system, etc.). These systems may be integrated with electronics for controlling their operation before, during, and after processing of a semiconductor wafer or substrate. The electronics may be referred to as the “controller,” which may control various components or subparts of the system or systems. The controller, depending on the processing requirements and/or the type of system, may be programmed to control any of the processes disclosed herein, including the delivery of processing gases, temperature settings (e.g., heating and/or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, positional and operation settings, wafer transfers into and out of a tool and other transfer tools and/or load locks connected to or interfaced with a specific system.
Broadly speaking, the controller may be defined as electronics having various integrated circuits, logic, memory, and/or software that receive instructions, issue instructions, control operation, enable cleaning operations, enable endpoint measurements, and the like. The integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and/or one or more microprocessors, or microcontrollers that execute program instructions (e.g., software). Program instructions may be instructions communicated to the controller in the form of various individual settings (or program files), defining operational parameters for carrying out a particular process on or for a semiconductor wafer or to a system. The operational parameters may, in some embodiments, be part of a recipe defined by process engineers to accomplish one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and/or dies of a wafer.
The controller, in some implementations, may be a part of or coupled to a computer that is integrated with the system, coupled to the system, otherwise networked to the system, or a combination thereof. For example, the controller may be in the “cloud” or all or a part of a fab host computer system, which can allow for remote access of the wafer processing. The computer may enable remote access to the system to monitor current progress of fabrication operations, examine a history of past fabrication operations, examine trends or performance metrics from a plurality of fabrication operations, to change parameters of current processing, to set processing steps to follow a current processing, or to start a new process. In some examples, a remote computer (e.g. a server) can provide process recipes to a system over a network, which may include a local network or the Internet. The remote computer may include a user interface that enables entry or programming of parameters and/or settings, which are then communicated to the system from the remote computer. In some examples, the controller receives instructions in the form of data, which specify parameters for each of the processing steps to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process to be performed and the type of tool that the controller is configured to interface with or control. Thus as described above, the controller may be distributed, such as by comprising one or more discrete controllers that are networked together and working towards a common purpose, such as the processes and controls described herein. An example of a distributed controller for such purposes would be one or more integrated circuits on a chamber in communication with one or more integrated circuits located remotely (such as at the platform level or as part of a remote computer) that combine to control a process on the chamber.
Without limitation, example systems may include a plasma etch chamber or module, a deposition chamber or module, a spin-rinse chamber or module, a metal plating chamber or module, a clean chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, and any other semiconductor processing systems that may be associated or used in the fabrication and/or manufacturing of semiconductor wafers.
As noted above, depending on the process step or steps to be performed by the tool, the controller might communicate with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout a factory, a main computer, another controller, or tools used in material transport that bring containers of wafers to and from tool locations and/or load ports in a semiconductor manufacturing factory.

Claims

What is claimed is:

1. A thermal management system for a substrate processing tool located in a fabrication room, the thermal management system comprising:

a blower that draws air from the fabrication room and causes the air to flow through a process module of the substrate processing tool, wherein heat is transferred from the process module to the air and the air is exhausted from the process module; and

a heat exchanger that receives the air exhausted from the process module, cools the air, and provides the cooled air to at least one of the fabrication room, a subfloor of the fabrication room, and the process module.

2. The thermal management system of claim 1, wherein at least one of the blower and the heat exchanger is located in the subfloor of the fabrication room.

3. The thermal management system of claim 1, wherein the substrate processing tool includes a plurality of process modules including the process module, and wherein each of the plurality of process modules is in fluid communication with a different one of a plurality of blowers.

4. The thermal management system of claim 1, wherein the substrate processing tool includes a plurality of process modules including the process module, and wherein each of the plurality of process modules is in fluid communication with a different one of a plurality of heat exchangers.

5. The thermal management system of claim 1, wherein the substrate processing tool includes a plurality of process modules including the process module, and wherein each of the plurality of process modules is in fluid communication with (i) a different one of a plurality of blowers and (ii) the heat exchanger.

6. The thermal management system of claim 5, further comprising a manifold that receives the air exhausted from each of the plurality of process modules and routes the air exhausted from each of the plurality of process modules to the heat exchanger.

7. The thermal management system of claim 1, wherein the heat exchanger includes a first heat exchanger and a second heat exchanger connected in series.

8. The thermal management system of claim 1, wherein the blower includes (i) a first blower connected between the process module and the heat exchanger in a flow path of the air exhausted from the process module and (ii) a second blower connected between the heat exchanger and the fabrication room in a flow path of the air cooled by the heat exchanger.

9. The thermal management system of claim 1, further comprising a damper connected between the process module and the heat exchanger in a flow path of the air exhausted from the process module.

10. The thermal management system of claim 1, further comprising a user interface module that monitors a parameter associated with the thermal management system and selectively controls at least one of the blower and the heat exchanger based on the monitored parameter.

11. The thermal management system of claim 10, wherein the parameter includes at least one of a temperature and a flow rate associated with the thermal management system.

12. A thermal management method for a substrate processing tool located in a fabrication room, method comprising:

drawing air from the fabrication room and causing the air to flow through a process module of the substrate processing tool, wherein heat is transferred from the process module to the air;

exhausting the air from the process module;

receiving the air exhausted from the process module;

cooling the air; and

providing the cooled air to at least one of the fabrication room, a subfloor of the fabrication room, and the process module.

13. The method of claim 12, further comprising providing at least one of a blower and a heat exchanger in the subfloor of the fabrication room.

14. The method of claim 12, further comprising providing fluid communication between each of a plurality of the process modules and a respective one of a plurality of blowers.

15. The method of claim 12, further comprising providing fluid communication between each of a plurality of the process modules and a respective one of a plurality of heat exchangers.

16. The method of claim 12, further comprising providing fluid communication between each of a plurality of the process modules and (i) a respective one of a plurality of blowers and (ii) a heat exchanger.

17. The method of claim 16, further comprising receiving the air exhausted from each of the plurality of the process modules at a manifold and routing the air exhausted from each of the plurality of the process modules from the manifold to the heat exchanger.

18. The method of claim 12, further comprising monitoring a parameter associated with the cooled air and selectively controlling at least one of a blower and a heat exchanger based on the monitored parameter.

19. The method of claim 18, wherein the parameter includes at least one of a temperature and a flow rate.