Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
  • H01L21/67005—Apparatus not specifically provided for elsewhere
  • H01L21/67011—Apparatus for manufacture or treatment
  • H01L21/67155—Apparatus for manufacturing or treating in a plurality of work-stations
  • H01L21/6719—Apparatus for manufacturing or treating in a plurality of work-stations characterized by the construction of the processing chambers, e.g. modular processing chambers
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
  • H01L21/67005—Apparatus not specifically provided for elsewhere
  • H01L21/67011—Apparatus for manufacture or treatment
  • H01L21/67017—Apparatus for fluid treatment

Definitions

• the present invention relates to dual chamber vacuum processing systems for processing semiconductor wafers and other substrates and, more particularly, to the sharing of hardware resources in such systems.
• Dual chamber vacuum processing systems have been developed in which certain hardware components are shared between the processing chambers. The idea is that, by sharing components between the chambers, the total cost of the system can be reduced without significantly adversely affecting wafer throughput. Examples of such dual chamber processing systems are disclosed in
• FIG. 1 A pumping system of an exemplary dual chamber vacuum processing system of the above patents is illustrated schematically in Figure 1.
• the system of Figure 1 generally includes two processing chambers 10, 12 which are both served by a single microwave source (not shown) that can be switched between the chambers 10, 12.
• the system includes two vacuum pumps 20, 22.
• a pump down pump 20 is operated to evacuate the chambers 10, 12 prior to processing.
• a process pump 22 is operated to evacuate the chambers 10, 12 during processing.
• Vacuum lines 26 connect the pumps 20, 22 to the chambers 10, 12. Isolation valves 30, 32, 34, 36 are provided in the vacuum lines 26 to selectively isolate the pumps 20, 22 from the chambers 10,
• the isolation valves 32 and 36 are open, and the isolation valves 30, 34 are closed.
• the isolation valves 30 and 34 are open, and the isolation valves 32, 36 are closed.
• a throttle valve 40 is provided upstream of the process pump 22 to regulate pressure in the chamber 10, 12 in which a substrate is being processed.
• the other chamber 10, 12 In operation, while one of the chambers 10, 12 is processing, the other chamber 10, 12 is vented, unloaded of a processed substrate, loaded with a fresh substrate, and pumped down. If all of these overhead operations can be performed while the first chamber 10, 12 is processing, the microwave source can be switched to the other chamber 10, 12 immediately after the first chamber 10, 12 is finished processing. Accordingly, the microwave source is fully utilized and, ideally, there is no system overhead time in which processing is not occurring in one of the chambers 10, To achieve this "zero overhead" operating condition, however, the system of Figure 1 requires four isolation valves 30, 32, 34, 35, two vacuum pumps 20, 22, and a relatively complex system of vacuum lines 26. These components, and especially the pumps 20, 22 can be relatively expensive. In addition, the pump down pump 20 is not fully utilized, because the actual pump down process constitutes only a relatively small proportion of the total overhead time.
• a photoresist ashing system in which additional components are shared to reduce cost without significantly adversely affecting wafer throughput.
• the system includes two processing chambers configured for alternate operation and a single pump that performs both pump down and process pumping of both of the chambers.
• a dual chamber processing system for continuously processing a plurality of workpieces comprises a common power source switchable between a first plasma applicator of a first chamber and a second plasma applicator of a second chamber.
• the first chamber is configured for processing a second worl ⁇ iece in a vacuum to completion therein when the power source is applied to the first plasma applicator and switched ON.
• a robot is provided for removing at substantially atmospheric pressure a first worl ⁇ iece from the second chamber after processing and reloading the second chamber with a third workpiece to be processed while the second worl ⁇ iece is being processed in the first chamber.
• the second chamber is configured for processing the third worl ⁇ iece in a vacuum to completion therein when the power source is applied to the second plasma applicator and switched ON.
• the robot is configured for removing at substantially atmospheric pressure the second worl ⁇ iece from the first chamber after processing and reloading the first chamber with a fourth worl ⁇ iece to be processed while the third worl ⁇ iece is being processed in the second chamber.
• Exactly one pump is provided and adapted to be in fluid communication with the first and second chambers. The pump is configured to perform both process pumping and pump-down
• a computer can be provided and configured to repeatedly synchronously and alternately control the power source application, the robot movement, the chamber processing, and the pumping.
• a method for processing substrates in a processing apparatus.
• the method comprises providing a first processing chamber, a second processing chamber; and a single a vacuum pump adapted to selectively communicate with the first processing chamber via a first vacuum line, and with the second processing chamber via a second vacuum line.
• the method further comprises alternately pumping the first and second chambers with the single pump.
• a method further comprises providing a first isolation valve in said first vacuum line, and a second isolation valve in said second vacuum line.
• the method includes opening the first isolation valve in the first vacuum line, pumping down the first processing chamber with the pump and processing a first substrate in the first processing chamber.
• the method further provides for unloading a second substrate from the second processing chamber.
• the method further comprises loading a third substrate into the second processing chamber, closing the first isolation valve in the first vacuum line, opening the second isolation valve in the second vacuum line, and pumping down the second processing chamber with the pump after completing the processing of the first substrate. Finally, the third substrate is processed in the second processing chamber.
• FIG. 1 is a simplified schematic diagram of a pumping system for a dual chamber substrate processing system of the prior art
• FIG. 2 is a simplified schematic diagram of a pumping system for a dual chamber substrate processing system according to one embodiment of the present invention
• FIG. 3 is a graphical representation of timing of preparation and processing phases using the pumping system of FIG. 1; and FIG. 4 is a graphical representation of timing of preparation and processing phases using the pumping system of FIG. 2.
• a dual-chamber processing system of the present invention can generally include: a plasma source with a switchable power supply, such as a microwave source or other suitable source; suitable robotic interfaces for loading and unloading wafers and performing other wafer-transfer steps; process gas sources; a venting system for bringing a chamber back to atmospheric pressure after a processing step is complete; and a pumping system for reducing the pressure within the chambers before and during wafer processing.
• the plasma source includes an individual remote plasma applicator associated with each of the chambers.
• the plasma source is in situ. Other additional components can also be used as desired.
• Figure 2 illustrates one embodiment of a pumping system for a dual chamber substrate processing system.
• the system of Figure 2 generally includes a first processing chamber 60 and a second processing chamber 62, which are both served by a single microwave or other power source (not shown) that can be switched between the chambers 60, 62.
• the illustrated system is designed for synchronously alternating processing of substrates, such that one while one chamber (60 or 62) is performing a processing step, the remaining chamber (60 or 62) can be unloaded of any processed wafers and re-loaded with wafers to be processed.
• the processing components operate on only one of the two chambers at any given time.
• the system has only one vacuum pump 64 configured to serve as both a process pump and a pump-down or evacuation pump for both of the chambers 60, 62.
• the pump 64 is utilized to rapidly reduce the pressure within the process chamber from atmospheric pressure (about 760 Torr) to a pressure at or near a desired process pressure (usually about 1 Torr) in about 3 to 5 seconds.
• the pump 64 is used to maintain the chamber at a desired process pressure for the duration of the substrate processing step.
• the pump is preferably sized for the maximum required pumping load, which can often be determined from the chamber size, the desired pump-down rate, and other variables.
• the pump 64 can be either a dry pump (i.e., one that does not require lubrication oil) or a wet pump (i.e., one that does use lubrication oil).
• a first vacuum line 66 connects the pump 64 to the first chamber 60.
• a second vacuum line 68 connects the pump 64 to the second chamber 62.
• Isolation valves 70,72 are provided in the vacuum lines 66, 68 to isolate the pump 64 from the chambers 60, 62, as desired.
• a throttle valve 80 is provided upstream of the pump 64 between the pump 64 and the isolation valves 70, 72 to control a flow rate of gas through the vacuum lines. Additional valves and vacuum lines can also be added as desired, for example, to bypass the throttle valve, etc.
• the steps of venting, unloading, re-loading and pumping down were performed in the first chamber 10 while simultaneously processing wafers (e.g. in a photoresist ashing process) in the second chamber 20 (the 'processing phase').
• the processing phase and the preparation phase take exactly the same length of time, thereby creating a "zero overhead condition" by allowing the power source to be switched from one chamber to the other with no idle time.
• the ideal "zero overhead" operating condition of the previous system is not always achieved because in some situations, the preparation phase takes slightly longer than the processing phase.
• a given process such as a photoresist removal process, may take roughly 15 seconds to complete. If the preparation phase also took 15 seconds to complete, the system would be operating at "zero overhead," and thus the system of Figure 1 could process 240 substrates per hour. In certain situations, however, the system of Figure 1 has been found to have a throughput rate of only 200 substrates per hour for a 15 second process, thus implying that the preparation phase can take slightly longer than the processing step.
• the isolation valve 70 of the first vacuum line 66 is opened and the isolation valve 72 of the second vacuum line 68 is closed, so that the pump 64 communicates with the first processing chamber 60.
• the throttle valve 80 can be adjusted to regulate the pressure in the first chamber 60 during processing by controlling a flow rate of gases drawn out of the chamber by the pump 64.
• the preparation phase 92 of the second chamber 62 is carried out.
• the preparation phase 92 includes venting, unloading, and reloading the chamber with a new substrate.
• the chambers can transition to their respective opposite phases by closing the isolation valve 70 of the first vacuum line 66 and opening the isolation valve 72 of the second vacuum line 68, so that the pump 64 communicates with the second chamber 62.
• the processing phase can then begin in the second chamber 62 by pumping down and processing in the second chamber 62. Thus, only one chamber is pumped at a time, and a single pump can serve this function.
• the preparation phase is carried out in the first chamber 60 by venting, unloading, and reloading the chamber 60 with a new substrate.
• the processing phase 102 is completed in the second chamber 62
• the preparation phase 92 will be completed in the first chamber 60.
• the chambers can then be transitioned again and the phases can be repeated.
• the pump down time is effectively subtracted from the total overhead time of the preparation phase 92 and added to the process phase 102. Accordingly, if it takes roughly 3 seconds to pump down one of the chambers 60, 62, and the process time is roughly 15 seconds, the other chamber has 18 seconds to vent, unload, and reload.
• the simplified system of Figure 2 can likely attain nearly the same throughput rate (200 substrates per hour in the example described above) as the more complex and costly system of Figure 1.
• one vacuum pump and two isolation valves of the previous system can be eliminated to provide a substantially less costly system.
• the layout of the vacuum lines 66, 68 of the system of Figure 2 is relatively simple, thus further cost savings are associated with a reduction of vacuum lines. As a result, the system of Figure 2 is cheaper and easier to maintain than the previous system.
• the microwave remote plasma source is not utilized during pump down, the vacuum pump 64, which is relatively expensive, is fully utilized and is never idling.
• the arrangement shown and described herein advantageously allows for elimination of one costly pump relative to prior systems and 100% utilization of the vacuum pump that is present.
• both machine cost and facility expense are reduced without sacrificing throughput or process times.
• the total process gas flow is on the order of 5 liters per minute for a typical single wafer chamber. Therefore, the gas going through the chamber being processed should be at a higher pressure than what is in the line.
• the vacuum lines are preferably of sufficient length to provide isolation between the two process chambers. To assist in isolation, the vacuum lines should also be fairly large in diameter to provide more volume for the air to expand from the chamber being pumped down.
• a bypass valve can be provided with a 1/4 inch line to slow the initial burst of air from the chamber being pumped down. A second or two later, the main ISO 80 valve can be opened, thereby providing a higher conductance to rapidly pump the remaining air from the chamber.

Landscapes

• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Condensed Matter Physics & Semiconductors (AREA)
• General Physics & Mathematics (AREA)
• Manufacturing & Machinery (AREA)
• Computer Hardware Design (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Power Engineering (AREA)
• Drying Of Semiconductors (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=30771084

Family Applications (1)

Country Status (3)

Cited By (2)

Families Citing this family (9)

Citations (3)

Family Cites Families (30)

• 2003
  • 2003-07-21 WO PCT/US2003/022676 patent/WO2004010482A1/en not_active Ceased
  • 2003-07-21 JP JP2004523187A patent/JP2005534174A/ja active Pending
  • 2003-07-21 US US10/624,728 patent/US20040089227A1/en not_active Abandoned

Patent Citations (3)

Also Published As

Similar Documents

Legal Events