Semiconductor reaction chamber with plasma capability

Abstract

A processing chamber includes a reaction chamber having a processing region, a process gas inlet in communication with the processing region, a first excited species generation zone in communication with the process gas inlet, and a second excited species generation zone in communication with the process gas inlet. A method of processing a substrate includes loading a substrate within the processing region, activating the first excited species generation zone to provide a first excited species precursor to the processing region during a first pulse, and activating the second excited species generation zone to provide a second excited species precursor different from the first excited species precursor to the processing region during a second pulse.

Description

[0001] This application is a divisional of application number 201810755771.X, filed on July 11, 2014, entitled "Semiconductor Reaction Chamber with Plasma Capability." TECHNICAL FIELD

[0002] The present disclosure relates generally to semiconductor processes, and more particularly to apparatuses and methods for providing excited species of process gases to a substrate or wafer in a reaction chamber. BACKGROUND

[0003] Semiconductor manufacturing processes are typically performed under controlled conditions with a substrate supported within a chamber. For many purposes, a semiconductor substrate (e.g., a wafer) is heated inside the processing chamber. For example, a substrate can be heated by direct physical contact with an internally heated wafer pedestal or "chuck." A "susceptor" is a wafer support used in systems in which the wafer and susceptor absorb heat.

[0004] Some of the important controlled conditions for a process include, but are not limited to: the pressure of the chamber, the fluid flow rate into the chamber, the temperature of the reaction chamber, the temperature of the fluid flowing into the reaction chamber, and the position of the wafer on the susceptor during wafer loading.

[0005] Heating within a reaction chamber can be performed in many ways, including a set or array of lamps positioned above the surface of the substrate for direct heating of the susceptor or a susceptor heater / pedestal heater positioned below the susceptor. Conventionally, a pedestal heater extends through a bottom wall into the chamber, while the susceptor is mounted on a top surface of the heater. The heater can include a resistive heating element enclosed within the heater to provide conductive heat and increase the temperature of the susceptor.

[0006] Consistent processes and consistent results often require careful control and metering of process gases in the system. One of the last points for controlling process gases is at the showerhead, where the process gases then contact the wafer in the reaction chamber. Additionally, it can sometimes be difficult to obtain optimal flow rates and uniformity due to the showerhead holes becoming clogged or parasitic precursor reactions occurring within the showerhead.

[0007] Plasma-based reactors can use a direct plasma integrated to the reactor or a remote plasma disposed upstream of the reactor. A direct plasma can form a more intense and effective plasma, but can also damage the substrate. Conversely, a remote plasma reduces the risk of damaging the substrate, but can encounter problems with the excited species being less active and thus not reacting properly with the thin film on the substrate. SUMMARY

[0008] Various aspects and implementations are disclosed herein relating to a reaction chamber having plasma capability for processing wafers. In one aspect, a processing chamber includes a reaction chamber having a processing region, a process gas inlet in communication with the processing region, a first excited species generation zone in communication with the process gas inlet, and a second excited species generation zone in communication with the process gas inlet.

[0009] In one implementation, the first and second excited species generation zones can be in communication with each other. The first and second excited species generation zones can be selectively in communication with each other. A valve can be positioned between the first excited species generation zone and the process gas inlet. A valve can be positioned between the second excited species generation zone and the process gas inlet. The first and second excited species generation zones can be non-coaxial.

[0010] The first and second excited species generation zones can be coaxially aligned. The first and second excited species generation zones can generate combustibly incompatible excited precursors. The first excited species generation zone can excite fluorine-based chemistry and the second excited species generation zone can excite chlorine-based chemistry. The first and second excited species generation zones can each further include an inductively coupled plasma generator. The inductively coupled plasma generators of the first and second excited species generation zones can be individually controlled. The first and second excited species generation zones can each further include a capacitively coupled plasma generator. The capacitively coupled plasma generators of the first and second excited species generation zones can be individually controlled.

[0011] The processing chamber can further include an inert gas flow positioned between the first and second excited species generation zones. The first and second excited species generation zones can be separated by an inert gas valve. The first and second excited species generation zones can be at least partially constructed of alumina or quartz. The first and second excited species generation zones can be excited with a single coil.

[0012] In another aspect, a method of processing a substrate can include the steps of loading a substrate within a processing region, activating a first excited species generation zone to provide a first excited species precursor to the processing region during a first pulse, and activating a second excited species generation zone to provide a second excited species precursor different from the first excited species precursor to the processing region during a second pulse.

[0013] In one implementation, the first and second excited species generation zones are different generation zones.

[0014] In another aspect, a method of delivering a plurality of precursors to a processing region can include the steps of: providing first and second excited species generation zones in communication with the processing region; selectively flowing a first precursor through the first excited species generation zone while exciting the first excited species generation zone; and selectively flowing a second precursor through the second excited species generation zone while exciting the second excited species generation zone.

[0015] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the DETAILED DESCRIPTION. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to determine the scope of the claimed subject matter. Furthermore, the claimed subject matter is not limited to implementations that solve any or all of the disadvantages of any of the problems in the art that are presented in any portion of this disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 A schematic cross-sectional view of a reaction chamber having a dual plasma generation region is shown.

[0017] Figure 2 A schematic cross-sectional view of a dual plasma generation region is shown.

[0018] Figure 3 A schematic cross-sectional view of a dual plasma generation region is shown.

[0019] Figure 4 A schematic cross-sectional view of a dual plasma generation region is shown.

[0020] Figure 5 A schematic top cross-sectional view of a dual plasma generation region of the second aspect is shown.

[0021] Figure 6 A schematic top cross-sectional view of a dual plasma generation region of the second aspect is shown taken generally along the line 6-6. Figure 5

[0022] Figure 7 A schematic cross-sectional view of a dual plasma generation region of the second aspect is shown.

[0023] Figure 8 A schematic cross-sectional view of a dual plasma generation region of the second aspect is shown.

[0024] Figure 9 A schematic top cross-sectional view of a dual plasma generation region of the third aspect is shown.

[0025] Figure 10 A schematic top cross-sectional view of a dual plasma generation region of the third aspect is shown.

[0026] Figure 11 ​An enlarged schematic cross-sectional view showing a dual plasma generation region of the fourth aspect. DETAILED DESCRIPTION

[0027] Aspects and implementations of the application can be described in the form of function blocks and various processing steps. Such function blocks can be implemented by any number of hardware or software components configured to perform the specified functions and achieve the various results. For example, aspects of the application can employ various sensors, detectors, flow control devices, heaters, etc. that perform a variety of functions. Further, aspects and implementations of the application can be practiced in conjunction with any number of processing methods and the described devices and systems can employ any number of processing methods, and the described devices and methods are merely examples of the application's application.

[0028] Figure 1 A processing chamber 18 is shown having a reaction chamber 20 with an upper chamber 22 and a lower chamber 24. The upper chamber 22 includes a showerhead 26, while the lower chamber 24 typically includes a susceptor assembly 28 well known in the art to receive a wafer 30 for loading, unloading, and processing. While the present disclosure shows and describes a showerhead 26 in a split chamber having an upper section and a lower section, it is within the spirit and scope of the present disclosure to incorporate the showerhead 26 into a non-split chamber reactor or a cross-flow reactor without a showerhead. As is otherwise well known, the showerhead 26 is fed by an inlet manifold 32 (or manifold port injectors or other suitable injection means in a cross-flow reactor) such that the gas flow within the reaction chamber is represented by arrows 33.

[0029] The inlet manifold 32 can include valves 34 well known in precursor delivery systems, and can be standard pneumatic valves, mechanical valves, inert gas valves, or any other suitable valve mechanism. Upstream of the valves 34 can be a separation tube 36 in some implementations having additional valves 38 and 40 similar to the valves 34 that are used to selectively isolate the various precursor inlets from one another. While not specifically shown, additional purge or vacuum ports and / or lines can be oriented downstream of the valves 38 and 40 to assist in purging the separation tube 36 and the inlet manifold 32. The valves 34, 38, and 40 can be individually controlled by a controller 42 via control lines 44, 46, and 48, respectively, or by any other suitable control system.

[0030] Precursor A 50 passes through outlet tube 52 upstream of valve 38, while precursor B 54 passes through outlet tube 56 upstream of valve 40. Precursor A 50 passes through first excited species generation zone 58, while precursor B 54 passes through second excited species generation zone 60. As can be seen, appropriate valves can be used to isolate the first and second excited species generation zones 58 and 60, such that reaction between the precursors flowing through each of the respective excited species generation zones can be prevented.

[0031] Each of the first and second excited species generation zones 58 and 60 can include a Faraday shield 62 on the outer periphery of each zone. The first excited species generation zone 58 can include control lines 64 and 66, while the second excited species generation zone 60 can include control lines 68 and 70. The various control lines 64, 66, 68, and 70 are connected to an excited species generation controller 72, as will be described in greater detail below.

[0032] Figure 2 A cross-sectional view of the first and second excited species generation zones 58, 60 is shown. Both the first and second excited species generation zones 58 and 60 include a Faraday shield 62, a safety sheath 74, an electrical coil 76, and a generation zone fitting 78. A cooling region 80 is formed between the safety sheath 74 and the generation zone fitting 78 to provide a flow of cooled inert gas to contact and maintain the electrical coil 76 positioned therein at a suitable operating temperature. The generation zone fitting 78 includes an opening 82 therein for receiving either precursor A 50 or precursor B, depending on which excited species generation zone the fitting is positioned in. Advantageously, the opening 82 is in fluid communication with an appropriate precursor bottle to supply the outlet tube 52 or 56 with process gas prior to the process gas reaching the reaction chamber, through the gate valve 38 or 40, and ultimately through the gate valve 34. The generation zone fitting 78 can be constructed of any suitable material for the precursor used in the opening 82. For example, when using precursors incorporating fluorine, oxygen, or hydrogen, the generation zone fitting can be alumina, while when using precursors incorporating chlorine, oxygen, or silicon chloride, the generation zone fitting can be quartz. The key is that the etching or deposition chemistry is compatible with the generation zone fitting material without undesirable reactions or particle generation. The electrical coil 76 is connected to the control lines 64, 66, or 68, 70, as appropriate, to provide an electrical current in the excited species generation zone to create a magnetic field and form an excited species within the appropriate opening 82 of either precursor A 50 or precursor B 54.

[0033] Referring now to the controller 72, the power and matching circuitry 84 is shown within the controller 72, while the switching circuitry 86 can also be integrated into the controller 72 and operated by a process chamber controller (not shown) according to suitable process recipes or procedures. The power and matching circuitry 84 is designed to provide the appropriate impedance and power to the electrical coil 76 to generate a sufficient amount of excited species within the appropriate generation zone plumbing 78 so that the excited species can move through the gate valve, showerhead, and ultimately the wafer surface along with the inert gas. It is further contemplated that each of the first and second excited species generation zones can require different or variable power, in which case the controller 72 can be adjusted to provide such variable current as needed, and the power circuitry can be powered using RF or any other suitable mechanism. Referring back to the valves 34, 38, and 40, an actuator 88 is positioned in each valve and is electrically or pneumatically controlled to open or close, depending on the process step being performed. Those skilled in the art will immediately appreciate that any suitable mechanism can be incorporated to prevent / allow gas flow through the valves, including the actuator 88 or any other device or method known in the art. Preferably, the valves will be able to have a high radical conductance to limit and / or prevent loss of excited species.

[0034] Figure 3 The precursor A 50 is shown being directed through the generation zone plumbing 78 as indicated by arrow 90, while Figure 4 The precursor B 54 is shown being directed through the generation zone plumbing 78 as indicated by arrow 92. In Figure 3 In the case where the precursor A 50 is necessary for the wafer process, the gate valve 40 remains in the closed position, while the gate valve 38 and the gate valve 34 open in the direction associated with arrow 94 after an appropriate amount of energy has been transferred to the precursor by the coil 76. Similarly, in the case where the precursor B 54 is necessary for the wafer process, the gate valve 38 remains in the closed position, while the gate valve 40 and the gate valve 34 open in the direction associated with arrow 94 after an appropriate amount of energy has been transferred to the precursor by the coil 76.

[0035] In operation, Figure 3 and Figure 4 The processes shown are performed separately so that the precursors do not meet whether or not they are excited. In some cases, if the precursors are mixed, severe damage will occur as a result. Furthermore, the excited species generation zones can be isolated from each other so that even if both excited species generation zones have activated species, only one of the activated species reaches the reaction chamber, or neither, during a chamber purge step. In another implementation, the switching circuitry 86 can be used to selectively activate only one appropriate excited species generation zone at a time to reduce power consumption. Finally, as can be seen in Figure 4As seen in FIG. 6, in one implementation, the first and second excited species generation zones can be staggered from one another and non-coaxial.

[0036] Figures 5 to 8 A second embodiment of first and second excited species generation regions 96 within a single Faraday shield 62 is shown. In this second implementation, precursor A 50 and precursor B 54 are positioned coaxially with one another and share the same excited species generation source or electrical coil 76 and safety sheath 74. Again, similar to the previous implementation, a cooled inert gas can flow through the electrical coil 76 and through the cooling region 80. The second implementation 96 can also direct an inert gas flow 98 directly through both the first and second excited species generation zones to direct the respective excited species precursors to the reaction chamber.

[0037] In the disclosed second implementation 96, precursor B 54 flows through an outer region 100 formed by region walls 102 and 104, which can be formed in a cylindrical shape from a material that is complementary or compatible with the precursor (alumina or quartz as non-limiting examples). A gap 106 can be positioned radially toward the interior of region wall 104, while region wall 108 forms a central opening 110. Region wall 108 is also preferably formed from a material that is complementary and compatible with the precursor used therein, and can be alumina or quartz as non-limiting examples.

[0038] Figure 7 Precursor A 50 is shown activated and moving through the central opening 110 as indicated by arrow 112. Precursor A 50 can move through the first excited species generation zone with the inert gas 98 and can exit the first excited species generation zone as the gate valve is opened to allow communication between the central opening 110 and the reaction chamber 20. Arrow 114 indicates the flow path of precursor B 54 and indicates that the gate valve blocks the flow such that precursor B 54 within the second excited species generation zone cannot exit the outer region 100. Thus, selectively excited precursors can be selectively provided to the reaction chamber with non-compatible precursors.

[0039] Figure 8Precursor B 54 is shown activated and moving through outer region 100 as indicated by arrow 116. Precursor B 54 can move through the second excited species generation zone along with inert gas 98 and can exit the second excited species generation zone as the gate valve is opened to allow communication between outer region 100 and reaction chamber 20. Arrow 118 indicates the flow path of precursor A 50 and indicates that the gate valve blocks the flow so that precursor A 50 within the first excited species generation zone cannot exit central opening 110. In operation, during a cycle during an etching or deposition process, precursor A 50 will be provided to reaction chamber 20 without precursor B 54 and subsequently precursor B 54 will be provided to reaction chamber 20 without precursor A 50. In this manner, incompatible precursors can be used within the reaction chamber without damage or danger.

[0040] Figure 9 and 10 A diagram of a third implementation of an excited species generation zone 120 having a capacitively coupled plasma generator instead of an inductively coupled plasma generator is shown and described as above. Again, region walls 102 and 104 can be cylindrical in shape and define an outer region 100 in which precursor A 50 can be excited and then selectively provided to reaction chamber 20. The plasma generator can include an inner electrode 122 and an outer electrode 124 connected to control lines 64 and 66, respectively. In operation, the inner electrode 122 and outer electrode 124 of the capacitively coupled plasma are activated by controller 72 and can selectively excite precursor A 50 prior to flowing the precursor into reaction chamber 20 for a deposition or etching process. Functionally, the third implementation of excited species generation zone 120 is similar to the previously described embodiments except for the incorporation of a capacitively coupled generator instead of an inductively coupled generator. Further, the third implementation of excited species generation zone 120 can use a generation zone similar to the non-coaxial arrangement of the first aspect and the second excited species generation zone 120 can be positioned in selective communication with the reaction chamber in a manner similar to those previously described without departing from the spirit and scope of the present disclosure.

[0041] Figure 11A fourth implementation of an excited species generation zone 126 is shown with a Faraday shield 62 and a safety shroud 74. Similar to the previous capacitively coupled plasma generators, the inner electrode 122 and the outer electrode 124 are positioned inside and outside of the precursor region, respectively. The outer region 128 is formed by a first wall 130 and a second wall 132, with the precursor flowing between the two walls. The inner region 134 is formed by a third wall 136 and a fourth wall 138. The walls 130, 132, 136, and 138 can be formed of any suitable material (alumina, quartz, etc.), depending on the precursor in contact with these particular walls. In operation, a single capacitively coupled plasma generator can excite the precursor in both the inner region 134 and the outer region 128, and the flow of those excited species is controlled by a gate valve. Alternatively, a separate capacitively coupled plasma generator can be used for each individual precursor, and the flow of excited species for each precursor can be independently controlled by a gate valve or based on plasma operation.

[0042] In operation, the wafer 30 is loaded on the pedestal 28, and the first precursor is activated or excited in one of the first or second excited species generation zones before passing through the necessary gate valve and through the showerhead 26 into the reaction chamber. Simultaneously, the second precursor can remain in the other of the excited species generation zones until the gate valve opens to allow passage therethrough. Next, the first precursor flow is stopped by the gate valve and the second excited precursor or inert gas can be provided to the reaction chamber. Since multiple implementations of the plasma generator have been shown and described, a single CCP or ICP can be operated continuously to maintain excited species in both excited species generation zones, or separate CCPs and ICPs can be used and triggered just prior to the need for excited species in the reaction chamber. In this manner, the inlet manifold and the reaction chamber can selectively receive excited species of any number of precursors without the precursors contacting each other during the process. Thus, it can be seen that by selectively flowing excited species activated in separate plasma generation zones, incompatible excited precursors can be used to process a wafer or etch a reaction chamber.

[0043] These and other embodiments for methods and apparatus for a reaction chamber having dual plasma generation regions therein can incorporate concepts, embodiments, and configurations as described with reference to embodiments for apparatus for measuring devices described above. The particular implementations shown and described are illustrative examples of the application and its best mode and are not intended to otherwise limit the scope of the aspects and implementations in any way. Indeed, for the sake of brevity, conventional manufacturing, connecting, preparing, and other functional aspects of the systems can not be described in detail. Furthermore, the connecting lines shown in the various figures are intended to represent exemplary functional relationships and / or physical couplings between the various elements. Many alternative or additional functional relationships or physical connections can be present in a practical system, and / or can be missing in some embodiments. Moreover, the various aspects and implementations of other designs can be combined into the scope of the present disclosure.

[0044] As used herein, the terms "comprises," "comprising," or any variation thereof, are intended to refer to a non-exclusive inclusion, such that a process, method, article, composition, or apparatus that comprises a list of elements does not include only those elements recited, but can also include other elements not expressly listed or inherent to such process, method, article, composition, or apparatus. Other combinations and / or modifications of the above-described structures, arrangements, applications, proportions, elements, materials or components used in the practice of the present application, in addition to those not specifically described above, can be varied or otherwise particularly adapted to specific environments, manufacturing specifications, design parameters or other operating requirements without departing from the general principles of the same.

Claims

1. A processing chamber, comprising: The reaction chamber has a processing area; A gas inlet is connected to the processing area; The first excited substance generation zone is connected to the processing gas inlet via a first gate valve; as well as The second excited substance generation zone is connected to the processing gas inlet via a second gate valve. The first and second gate valves are controlled such that the reaction chamber is selectively exposed to a first excited substance from the first excited substance generation region and a second excited substance from the second excited substance generation region; and The first and second excited substance generation regions are coaxially aligned.

2. The processing chamber as described in claim 1, characterized in that, The first excited substance generation region and the second excited substance generation region are within the Faraday shield.

3. The processing chamber as described in claim 1, characterized in that, The first excited material generation region includes an inductively coupled plasma generator.

4. The processing chamber as described in claim 1, characterized in that, The first excited material generation region includes a capacitively coupled plasma generator.

5. An apparatus for processing a substrate, the apparatus comprising: The first excited substance generation zone is connected to the processing gas inlet via a first gate valve; as well as The second excited substance generation zone is connected to the processing gas inlet via a second gate valve. The first and second gate valves are controlled such that a first excited substance from the first excited substance generation region and a second excited substance from the second excited substance generation region are selectively introduced into the inlet of the reaction zone; and The first and second excited substance generation regions are coaxially aligned.

6. A processing chamber, comprising: The reaction chamber has a processing area; A gas inlet is connected to the processing area; Faraday shielding; The first excited substance generation zone is connected to the processing gas inlet via a first gate valve; as well as The second excited substance generation zone is connected to the processing gas inlet via a second gate valve. Both the first excited substance generation region and the second excited substance generation region are contained within the Faraday shield; The first and second gate valves are controlled such that the reaction chamber is selectively exposed to a first excited substance from the first excited substance generation region and a second excited substance from the second excited substance generation region; and The first and second excited substance generation regions are coaxially aligned.

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