Actuator for dynamically adjusting showerhead tilt

Abstract

To provide a semiconductor substrate processing apparatus, a showerhead module adjustment mechanism, and an energization mechanism that suppress non-uniform film deposition (that is, azimuthal variation) during substrate processing.SOLUTION: A showerhead module adjustment mechanism 400 for supporting a showerhead module 211 within a top plate of a semiconductor substrate processing apparatus is dynamically operable to adjust the planarization of the faceplate of the showerhead module with respect to the top surface of the substrate pedestal module adjacent a faceplate 316 in the semiconductor substrate processing apparatus. The flatness of the showerhead module can be coarsely adjusted by tightening or loosening an adjustment screw 405.SELECTED DRAWING: Figure 3A

Description

[Technical field]

[0001] The present invention relates to semiconductor substrate processing equipment used to process semiconductor substrates, and may find particular use in performing chemical vapor deposition of thin films. [Background technology]

[0002] Semiconductor substrate processing equipment is used to process semiconductor substrates by techniques such as physical vapor deposition (PVD), chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), plasma enhanced atomic layer deposition (PEALD), pulsed deposited layer (PDL), molecular layer deposition (MLD), plasma enhanced pulsed deposited layer (PEPDL) processing, etching, and resist stripping. One type of semiconductor substrate processing equipment used to process semiconductor substrates includes a reaction chamber containing a showerhead module and a substrate pedestal module that supports the semiconductor substrate within the reaction chamber. The showerhead module delivers process gases into the reaction chamber so that the semiconductor substrate can be processed. In such chambers, it can be time consuming to install and remove the showerhead module, and further, if the bottom surface of the showerhead module is not parallel to the top surface of the substrate pedestal module, non-uniform deposition (i.e., azimuthal variation) can occur during substrate processing. Summary of the Invention

[0003] Disclosed herein is a semiconductor substrate processing apparatus for processing semiconductor substrates, the semiconductor substrate processing apparatus including: a chemical separation chamber in which individual semiconductor substrates are processed and a top plate forming a top wall; a process gas source in fluid communication with the chemical separation chamber for supplying process gas into the chemical separation chamber; a showerhead module delivering process gas from the process gas source to a processing zone of the semiconductor substrate processing apparatus in which the individual semiconductor substrates are processed, the showerhead module having a base attached to a lower end of a stem and a faceplate forming a lower surface of the base with gas passages therethrough; a substrate pedestal module configured to support a semiconductor substrate in the processing zone below the faceplate during processing of the substrate; and a showerhead module adjustment mechanism supporting the showerhead module in the top plate, the showerhead module adjustment mechanism being dynamically operable to adjust planarization of the showerhead module faceplate relative to an upper surface of the substrate pedestal module adjacent the faceplate, the showerhead module adjustment mechanism including at least one actuator assembly.

[0004] The showerhead module adjustment mechanism can include at least one actuator assembly that dynamically enables movement of the showerhead module in at least one tilting direction. The at least one actuator assembly can include a lever that mechanically amplifies the displacement of the piezoelectric stack and a flexure attachment for coupling the lever to an actuator case. The at least one actuator assembly can further include an upper flexure coupled between a top end of the piezoelectric stack and the actuator case encasing the piezoelectric stack, the flexure attachment coupled between a bottom end of the piezoelectric stack and the lever, the upper flexure and the flexure attachment configured to relieve stress on the piezoelectric stack. The showerhead module adjustment mechanism can be configured such that (a) the three actuator assemblies effect two tilt movements and one axial translation of the showerhead module, (b) an end of the lever opposite the piezoelectric stack causes movement of an adjustment screw coupled to the top plate of the bellows assembly, (c) an end of the lever opposite the piezoelectric stack acts on a ball joint of the adjustment screw through a socket-and-groove, (d) the showerhead module is attached to the top plate of the bellows assembly, (e) the flexure mount limits lateral and vertical translation of the lever, (f) the combined thermal expansion of the upper flexure, the flexure mount, and the actuator case matches the thermal expansion of the piezoelectric stack, or (g) the showerhead module adjustment mechanism dynamically adjusts the tilt of the showerhead module faceplate over a range of about 3 milliradians. The showerhead module adjustment mechanism can dynamically adjust the position of the showerhead module faceplate with a resolution of better than 0.15 milliradians.

[0005] In one embodiment of the actuator assembly, the at least one actuator assembly further includes a lever that mechanically amplifies the displacement of the piezoelectric stack, a ball and socket joint coupled to the lever and a bottom end of the piezoelectric stack, and an upper flexure coupled between a top end of the piezoelectric stack and an actuator case that contains the piezoelectric stack. [Brief description of the drawings]

[0006] [Figure 1] 1 is an explanatory diagram showing an overview of a chemical film formation apparatus according to an embodiment disclosed herein;

[0007] [Diagram 2] FIG. 1 is a block diagram illustrating various apparatus components arranged to implement embodiments disclosed herein in which plasma can be used to enhance film deposition and / or surface reactions between reactive species during the production of thin films.

[0008] [Figure 3A] FIG. 1 illustrates a showerhead assembly arranged in accordance with embodiments disclosed herein. [Figure 3B] FIG. 1 illustrates a showerhead assembly arranged in accordance with embodiments disclosed herein.

[0009] [Figure 4] FIG. 2 is a cross-sectional view of a showerhead module adjustment mechanism arranged in accordance with embodiments disclosed herein.

[0010] [Figure 5A] FIG. 2 illustrates an actuator assembly arranged in accordance with an embodiment disclosed herein. [Figure 5B] FIG. 2 illustrates an actuator assembly arranged in accordance with an embodiment disclosed herein. [Figure 5C] FIG. 2 illustrates an actuator assembly arranged in accordance with an embodiment disclosed herein.

[0011] [Figure 6A] FIG. 2 illustrates an actuator assembly arranged in accordance with an embodiment disclosed herein. [Figure 6B] FIG. 2 illustrates an actuator assembly arranged in accordance with an embodiment disclosed herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] In the following detailed description, numerous specific embodiments are described to provide a thorough understanding of the apparatus and methods disclosed herein. However, those skilled in the art will appreciate that these embodiments may be practiced without these specific details or by using alternative elements or processes. Additionally, well-known processes, procedures, and / or components have not been described in detail so as not to unnecessarily obscure aspects of the embodiments disclosed herein. As used herein in connection with numerical values, the term "about" means ±10%.

[0013] As discussed above, these embodiments provide semiconductor substrate processing apparatus, such as a deposition apparatus (or in an alternative embodiment, an etching apparatus) for performing chemical vapor deposition, such as plasma enhanced chemical vapor deposition, and associated methods. The apparatus and methods are particularly applicable for use in conjunction with semiconductor fabrication-based dielectric or metal deposition processes that require separation of self-limiting deposition steps in a multi-step deposition process (e.g., atomic layer deposition (ALD), plasma enhanced atomic layer deposition (PEALD), plasma enhanced chemical vapor deposition (PECVD), pulsed deposited layer (PDL), molecular layer deposition (MLD), or plasma enhanced pulsed deposited layer (PEPDL) processes). Representative embodiments of methods for processing semiconductor substrates can be found in commonly owned published U.S. Patent Application Nos. 2013 / 0230987, 2013 / 0005140, and 2013 / 0319329, as well as U.S. Pat. Nos. 8,580,697, 8,431,033, and 8,557,712, which are incorporated by reference in their entireties.

[0014] The above-described processes can suffer from several drawbacks related to non-uniform process gas delivery to an upper surface of a wafer or semiconductor substrate undergoing deposition from process gases, such as process gas precursors or process gas reactants. For example, if a lower surface of a showerhead module that delivers process gases to the semiconductor substrate is not parallel to an upper surface of a substrate pedestal module that supports the semiconductor substrate, non-uniform precursor distribution can be formed on the upper surface of the semiconductor substrate.

[0015] Generally, there are two main types of CVD showerhead modules: chandelier-type and recessed-type. A chandelier-type showerhead module resembles a chandelier, with a stem attached at one end to the top plate of the reaction chamber and at the other end to the faceplate. A portion of the stem may protrude above the top plate to allow for the connection of gas lines and radio frequency ("RF") power. A recessed-type showerhead module is integrated into the top of the chamber and does not have a stem. The example shown herein is a chandelier-type showerhead module, but the showerhead module is not limited to this type of showerhead.

[0016] After a wet cleaning procedure involving one or more cooling and venting of the reaction chamber (chemical separation chamber) of the apparatus, showerhead module leveling (planarization) is usually performed. Cooling and venting may be required to access the interior of the chamber to adjust the spacing between the showerhead and the substrate pedestal module and to planarize the lower surface of the showerhead against the upper surface of the pedestal module. Conventional techniques involve placing metal foil balls in the chamber to measure the gap between the showerhead module and the substrate pedestal module, and adjusting multiple support rods, usually three or more, between the back plate of the showerhead module and the top plate of the reaction chamber based on the results of the measurement. The support rods can only be adjusted by opening the top plate after venting and cooling the chamber. Multiple cycles of measurement and adjustment may be performed before the showerhead module is considered to be level. Since the showerhead cannot be leveled through external manipulation, the process is very time consuming and can take up to about 20 hours.

[0017] In one embodiment, one or more piezoelectric actuators are used to provide further dynamic fine tuning in addition to this manual adjustment procedure. Processes often require different types of films to be deposited sequentially on the same wafer, and different films will have different sensitivities to showerhead tilt. Piezoelectric actuators are ideal for this application because they can control position changes in the sub-nanometer range by translating small changes in actuation voltage into smooth motion. The motion controlled by a piezoelectric actuator is not affected by friction or threshold voltages. Piezoelectric actuators also provide fast response times, and are capable of accelerations in excess of tens of thousands of g's. Piezoelectric actuators do not generate or are affected by magnetic fields, and therefore are particularly suitable for applications with low magnetic field tolerance. Finally, piezoelectric actuators have no gears or rotating shafts, and therefore their displacement is based on solid-state dynamics and does not exhibit wear.

[0018] However, currently available motorized actuators and stages, including commercially available piezoelectric stages, do not meet the force (80 pounds-force per actuator), resolution (0.15 milliradians), durability (10,000,000 cycles), or encapsulation requirements required for showerhead tilt adjustment. For example, motorized lead screw actuators either do not have enough force (10-15 pounds-force per actuator) or are too large to be encapsulated within a semiconductor processing tool. Standalone piezoelectric stacks can provide sufficient force, but their maximum displacement is very small, typically on the order of 0.1% of their length. Other commercially available piezoelectric stages designed for nanometer precision and with near-zero mutual coupling between multiple directions do not have sufficient range of motion or the required force.

[0019] Disclosed herein is a showerhead module coupled to a showerhead module adjustment mechanism designed to be leveled from outside the reaction chamber between process steps on the same wafer. In processes where two or more different film materials are grown sequentially, dynamic adjustment of the showerhead tilt compensates for azimuthal variations without breaking vacuum. The showerhead actuator assembly preferably incorporates a lever with a gain ratio between 2 and 20, and to improve the range of motion of a standalone piezoelectric stack, a desired gain ratio such as, for example, 6.5:1 may be used. A piezoelectric actuator with integrated lever motion amplifier will typically increase the piezoelectric stack displacement by a factor of 2-20. To maintain high resolution and fast response with increased range of motion, it is preferred that the lever system be stiff and free of backlash and friction, which is why ball or roller bearings are not preferred. A piezoelectric actuator with integrated motion amplifier has several advantages over a standard piezoelectric actuator, such as induced motion, decoupling of forces from the ceramic, compact size compared to stack actuators of equal displacement, and reduced capacitance.

[0020] In a preferred configuration, the piezoelectric stack exerts sufficient actuation force (at least 80 lb·force) on the adjustment point even after the actuation force is reduced by the lever. Additionally, the flexure ensures that the lever assembly functions without friction and wear, which is desirable for extending actuator life. The flexure is a frictionless, non-sticting device based on elastic deformation (flexure) of solid materials. Slipping and rolling are completely eliminated. In addition to the absence of internal friction, the flexure device exhibits high stiffness and load capacity. The flexure is less sensitive to shock and vibration compared to other guidance systems and may also act as a stress relief for the piezoelectric stack, allowing kinematic movement in the desired direction, thus allowing the actuator to achieve its full range of motion, further extending actuator life.

[0021] FIG. 1 is a schematic diagram of a semiconductor substrate processing apparatus 201 for chemical vapor deposition according to an embodiment disclosed herein. A semiconductor substrate 13, such as a wafer, sits on a movable pedestal module 223 that can be raised or lowered relative to a showerhead module 211. The showerhead module 211 can also be moved vertically. Reactive material gases are introduced into the processing zone 318 of the chamber through gas lines 203, and the flow of the process gases is controlled by mass flow controllers 229. It should be noted that the apparatus can be modified to have one or more gas lines depending on the number of reactive gases used. The chamber is evacuated through a vacuum line 235 connected to a vacuum source 209. The vacuum source can be a vacuum pump.

[0022] The embodiments disclosed herein can be implemented in a plasma-enhanced chemical deposition apparatus (i.e., a plasma-enhanced chemical vapor deposition (PECVD) apparatus, a plasma-enhanced atomic layer deposition (PEALD) apparatus, or a plasma-enhanced pulsed deposition layer (PEPDL) apparatus). FIG. 2 provides a simplified block diagram illustrating various apparatus components arranged to implement the embodiments disclosed herein, where a plasma is used to enhance deposition. As shown in the figure, the processing zone 318 serves to contain the plasma generated by a capacitively coupled plasma system including a showerhead module 211 in cooperation with a substrate pedestal module 223, which is heated. An RF source (or sources), such as at least one high frequency (HF) RF generator 204, is connected to a matching network 206, and an optional low frequency (LF) RF generator 202 is connected to the showerhead module 211. In an alternative embodiment, the HF generator 204 can be connected to the substrate pedestal module 223. The power and frequency provided by the matching network 206 is sufficient to generate a plasma from the process gas / vapor. In one embodiment, both the HF generator and the LF generator are used, and in an alternative embodiment, only the HF generator is used. In a typical process, the HF generator is operated at a frequency of about 2-100 MHz, and in a preferred embodiment, at 13.56 MHz or 27 MHz. The LF generator is operated at a frequency of about 50 kHz to 2 MHz, and in a preferred embodiment, at about 350-600 kHz. The process parameters may be scaled based on the chamber volume, substrate size, and other factors. Similarly, the flow rate of the process gas may be determined by the free volume of the vacuum chamber (reaction chamber) or processing zone.

[0023] Within the chamber, a substrate pedestal module 223 supports a substrate 13 on which a material such as a thin film may be grown. The substrate pedestal module 223 may include forks or lift pins for holding and transporting the substrate during and between deposition and / or plasma treatment reactions. In one embodiment, the substrate 13 may be configured to rest on a surface of the substrate pedestal module 223, although in alternative embodiments, the substrate pedestal module 223 may include an electrostatic chuck, a mechanical chuck, or a vacuum chunk for holding the substrate 13 on the surface of the substrate pedestal module 223. The substrate pedestal module 223 may be coupled to a heater block 220 for heating the substrate 13 to a desired temperature. The substrate 13 is maintained at a temperature of about 25-500° C. or higher, depending on the material being grown.

[0024] In certain embodiments, a system controller 228 is used to control process conditions during deposition, post-deposition, and / or other process operations. The controller 228 typically includes one or more memory devices and one or more processors, which may include a CPU or computer, analog and / or digital input / output connections, stepper motor control boards, etc.

[0025] In certain embodiments, the controller 228 controls all activity of the apparatus. The system controller 228 executes system control software that includes a set of instructions for controlling the timing of process operations, the operating frequencies and powers of the LF generator 202 and HF generator 204, the flow rates and temperatures of the precursor and inert gases and their relative mixtures, the temperature of the heater block 220 and showerhead module 211, the chamber pressure, the showerhead tilt, and other parameters of a particular process. In some embodiments, other computer programs stored in memory associated with the controller may be used.

[0026] Typically, a user interface is associated with the controller 228. The user interface may include a display screen, a graphical software representation of equipment and / or process conditions, and user input devices such as a pointing device, keyboard, touch screen, microphone, etc.

[0027] A non-transitory computer machine readable medium may contain program instructions for controlling an apparatus. The computer program code for controlling processing operations may be written in any conventional computer readable programming language, such as, for example, assembly language, C, C++, Pascal, Fortran, etc. The compiled object code or script is executed by a processor to perform tasks specified in the program.

[0028] The controller parameters relate to process conditions such as, for example, timing of processing steps, precursor and inert gas flow rates and temperatures, wafer temperature, chamber pressure, showerhead tilt, and other parameters of a particular process. These parameters are provided to the user in the form of a recipe and may be entered using a user interface.

[0029] Signals for monitoring the process may be provided by analog and / or digital input connections of the system controller, and signals for controlling the process are output on analog and digital output connections of the device.

[0030] The system software may be designed or configured in a variety of ways. For example, various chamber component subroutines or control objects may be written to control the operation of the chamber components required to perform a deposition process. Examples of programs or program portions for this purpose include code for timing of substrate processing steps, code for precursor and inert gas flow rates and temperatures, and code for chamber pressure.

[0031] The showerhead module 211 is preferably temperature controlled and RF powered. One exemplary embodiment of a temperature controlled, RF powered showerhead module can be found in commonly owned published U.S. Patent Application No. 2013 / 0316094, which is incorporated by reference herein in its entirety.

[0032] According to embodiments disclosed herein, the showerhead module preferably includes a showerhead module adjustment mechanism for manually and dynamically adjusting the planarization (parallelization) of the showerhead module. As illustrated in FIG. 3A and FIG. 3B, the showerhead module 211 preferably includes a base 315 including a stem 305, a back plate 317, and a face plate 316, and a showerhead module adjustment mechanism 400 for adjusting the planarization of the showerhead module 211. The planarization of the showerhead module 211 can also be coarsely adjusted by tightening or loosening an adjustment screw 405. The adjustment screw 405 includes a fine thread and can be used to manually adjust the showerhead module 211 in two degrees of tilt and axial position. The adjustment screw 405 mates with a socket groove 430 of the actuator assembly. The planarization of the showerhead module 211 can be finely and dynamically adjusted by manipulating the piezoelectric stack displacement of the piezoelectric actuator through an integrated lever motion amplifier.

[0033] In one embodiment, the planarization of the faceplate 316 of the showerhead module 211 can be adjusted using three actuator assemblies as part of the showerhead adjustment mechanism to dynamically provide three degrees of freedom: one axial translation and two tilt directions. In another embodiment, two actuator assemblies may be used to provide two degrees of freedom. In yet another embodiment, one actuator assembly may be used to provide one degree of freedom (e.g., dynamic tilt in one direction). The design of the showerhead module 211 and showerhead module adjustment mechanism 400 uses fast response (e.g., less than one second) piezoelectric actuator assemblies to dynamically adjust the tilt of the showerhead module 211, thus allowing for improved uniformity in the growth of a particular film selected from a number of different film types.

[0034] 4, the showerhead module 211 is preferably supported within a top plate 330 of a chemical separation chamber (i.e., reaction chamber). The top plate 330 preferably supports a collar 413. The horizontal top surface of the top plate 330 preferably has openings, such as threaded openings, and corresponding openings in the collar 413 for receiving fasteners include at least three fasteners 402 that attach the collar 413 to the top plate 330. The collar 413 supports the remainder of the showerhead module adjustment mechanism 400 within the top plate 330. The showerhead module adjustment mechanism 400 is grounded by the top plate 330.

[0035] An O-ring 409 forms an airtight seal (i.e., hermetic seal) between the top plate 403 of the bellows assembly and the cold plate 412, which is supported above the collar 413 by at least three adjustable adjustment screws 405. The at least three adjustable adjustment screws 405 are also operable to coarsely adjust the flattening of the cold plate 412 relative to the collar 413. Preferably, an upper end of each adjustment screw 405 is threadably supported within the top plate 403 of the bellows assembly, and a lower end of each adjustment screw (i.e., ball joint 425) is rotatably received within a socket groove 430 of the actuator assembly. The showerhead stem 305 is attached to the upper surface of the cold plate 412 by another O-ring 409 that passes through openings in the collar 413, the bellows 411, and the cold plate 412 and forms a hermetic seal between the flange 416 and the cold plate 412. Additionally, the flange 416 and the cold plate 412 may be brazed together. The stem 305 of the showerhead module 211 is supported within an opening in the top plate 330 by fasteners 402 that attach a collar 413 to the top plate 330 .

[0036] The bellows 411 preferably forms an airtight, expandable, and flexible vacuum seal between the collar 413 and the cooling plate 412, and the stem 305 extends through the airtight, expandable vacuum seal such that the flattening of the showerhead module 211 is adjustable without breaking the airtight, expandable vacuum seal. The bellows 411 is preferably welded at its upper end to the top plate 403 and at its lower end to the collar 413.

[0037] The showerhead module adjustment mechanism 400 may be attached to the top plate 330 of the chemical separation chamber through three or more fasteners 402. The showerhead adjustment mechanism may contain from one to three actuator assemblies. Each actuator assembly provides one degree of motion. Three actuator assemblies would provide three degrees of motion: two tilts and one axial position. A reduced cost version would use one actuator and provide tilt in one dimension.

[0038] 5A-5C illustrate one embodiment of an actuator assembly. In each actuator assembly, a piezoelectric stack 419 is mounted within an actuator case 421. The piezoelectric stack 419 is made of a material that increases in length when a voltage is applied, and the change in length is approximately linear with respect to the voltage, approximately 0.1% at 100V. Because the piezoelectric stack alone can only provide this small amount of motion, a lever 422 is fabricated within the actuator case 421 to amplify the range of motion of the showerhead module adjustment mechanism 400 and simultaneously reduce the force by at least 2:1, preferably at least 4:1, and in one preferred embodiment, 6.5:1. Higher or lower lever gains may be used. For example, a higher ratio allows a wider range of motion but with less force, and a lower ratio provides more force but with a narrower range of motion. The lever 422 is typically fabricated using an electrical discharge machining (EDM). The lever pivot (or fulcrum) is a blade-like flexure 415 that is designed to flex.

[0039] An electric discharge machining (EDM) cut flexure, including flexure mount 423 and upper flexure portion 424 (e.g., part of the screw fastener), is housed in actuator case 421 and allows a small amount of tilt of lever 422 while limiting movement in other directions. Flexure mount 423 provides a low stress connection between piezoelectric stack 419 and lever 422 of actuator case 421 and is designed to be flexible in bending yet extremely stiff in compression. In this implementation, flexure mount 423 is a cross-blade flexure. Flexure mount 423 may be fabricated using a rapid prototyping technique such as direct metal laser sintering (DMLS). DMLS or other rapid prototyping techniques are preferred for rapidly fabricating highly complex geometries that cannot be easily fabricated using traditional machining techniques such as milling.

[0040] The upper flexure 424 is part of a screw fastener that is screwed into the actuator case 421 using fine pitch threads until the piezoelectric stack 419 is lightly wedged between the flexure mount 423 and the screw fastener. The screw fastener can therefore accommodate assembly tolerances between the actuator case 421, the piezoelectric stack 419 and the flexure mount 423. The screw fastener is also designed to be flexible in bending but extremely stiff in compression. The flexure mount 423 and upper flexure 424 at the bottom and top ends of the piezoelectric stack 419, respectively, are needed to reduce stress on the piezoelectric stack 419 to eliminate friction and to allow the kinematic freedom required to actuate the lever 422.

[0041] The blade-like flexure 415 provides a frictionless pivot for the lever 422, which increases the accuracy and reliability of the lever 422's operation. Furthermore, the combination of the piezoelectric element and the EDM cut flexure allows the actuator to achieve high displacement and high driving force. The end of the lever 422 opposite the piezoelectric stack 419 acts on a ball joint 425 of the adjustment screw 405 through a socket groove 430. The ball joint 425 then acts on the top plate 403 of the bellows assembly to adjust the flattening of the face plate 316 of the showerhead module 211 attached to the top plate 403 of the bellows assembly. The bellows assembly is made up of the top plate 403, the bottom plate 426, and the bellows 411, which are welded together. The bottom plate 426 is attached to the top plate 330 of the chamber, and the top plate 403 of the bellows assembly is attached to the cold plate 412, which is attached to the showerhead. The bellows assembly is flexible and top plate 403 can move relative to bottom plate 426 as bellows 411 flexes.

[0042] The adjustment screw 405 may be used for coarse adjustment of the position of the showerhead module 211. The combination of coarse adjustment by the screw and dynamic fine adjustment by the piezoelectric actuator allows the showerhead module 211 to be manually adjusted over a wide displacement range to accommodate manufacturing tolerances and then dynamically adjusted between process steps.

[0043] Materials were selected to insulate the actuator so that the tilt of the showerhead module 211 would not waver over the wide operating temperature range experienced during the deposition process. Materials such as Invar, Nitronic 60, and Titanium were selected so that the combined thermal expansion of the actuator case, screw fixings, and flexure mountings would match that of the piezoelectric stack.

[0044] Figures 6A and 6B illustrate another embodiment of an actuator assembly. If a flexure mount (Figures 5A-5C) cannot be fabricated, it may be advantageous to use a ball and socket joint 523 at the bottom end of the piezoelectric stack 419 in each actuator assembly. In the configuration of Figures 6A and 6B, the piezoelectric stack 419 has the same kinematic freedom as when a flexure mount 423 is used. The ball joint configuration provides a low stress connection between the piezoelectric stack and the lever of the actuator case by allowing pivoting motion while still being stiff in compression. Wear may also be reduced by using a gothic arch geometry to maximize contact area and reduce Hertzian stresses, and by using materials such as Nitronic 60 that are resistant to abrasion.

[0045] The embodiment shown in FIGS. 5A-6B allows for dynamic adjustment of the showerhead module 211 to control the gap height between the faceplate 316 and the top surface of the substrate pedestal module 223. The showerhead tilt affects the thickness profile of the film grown on the substrate. Since different substrates have different sensitivities to showerhead tilt, it is advantageous from the standpoint of manufacturing efficiency and maintenance costs to dynamically adjust the showerhead tilt without breaking vacuum. The embodiment shown in FIGS. 5A-6B also meets the actuation force (80 pounds-force per actuator), resolution (0.15 milliradians), durability (10,000,000 cycles), and range of motion (3 milliradians) requirements of modern showerhead adjustment mechanisms.

[0046] Preferably, the system controller 228 is electrically connected to at least one in-situ sensor (detector) for measuring the gap height between the face plate 316 and the top surface of the substrate pedestal module 223 and the flatness of the face plate 316 relative to the top surface of the substrate pedestal module 223, so that the gap control and the flatness control can be performed in a feedback control mode. Various types of in-situ detectors can be used as the gap and flatness sensor, such as laser interferometers, inductive sensors, capacitive sensors, acoustic sensors, linear variable differential transformers (LDVTs), and strain gauge sensors, and the sensors can be located either inside or outside the chemical separation chamber. The sensors can be integrated into the actuators, thus enabling closed-loop feedback control and also providing a means to detect non-functioning actuators.

[0047] Although a semiconductor substrate processing apparatus including a baffle configuration has been described in detail with reference to specific embodiments thereof, it will be apparent to those skilled in the art that various changes and modifications may be made thereto without departing from the scope of the appended claims, and equivalents may be utilized. The present disclosure can also be realized as the following application examples. <Application example 1> A semiconductor substrate processing apparatus for processing a semiconductor substrate, comprising: a chemical separation chamber in which individual semiconductor substrates are processed and in which the top plate forms an upper wall; a process gas source in fluid communication with the chemical separation chamber for supplying a process gas into the chemical separation chamber; a showerhead module for delivering process gas from the process gas source to a processing zone of the semiconductor substrate processing apparatus in which the individual semiconductor substrates are processed, the showerhead module having a base attached to a lower end of a stem and a faceplate having gas passages extending therethrough forming a lower surface of the base; a substrate pedestal module configured to support the semiconductor substrate within the processing zone beneath the faceplate during processing of the substrate; a showerhead module adjustment mechanism supporting the showerhead module within the top plate, the showerhead module adjustment mechanism being dynamically operable to adjust a planarization of the faceplate of the showerhead module relative to an upper surface of the substrate pedestal module adjacent the faceplate, the showerhead module adjustment mechanism including at least one actuator assembly; A semiconductor substrate processing apparatus comprising: <Application example 2> The semiconductor substrate processing apparatus according to Application Example 1, 11. The semiconductor substrate processing apparatus of claim 10, wherein the at least one actuator assembly includes at least one piezoelectric stack that dynamically enables movement of the showerhead module in at least one tilted direction. <Application example 3> The semiconductor substrate processing apparatus according to Application Example 2, The at least one actuator assembly further includes a lever that mechanically amplifies a displacement of the at least one piezoelectric stack, the lever fulcrum being a blade-shaped flexure. <Application Example 4> The semiconductor substrate processing apparatus according to Application Example 3, The at least one actuator assembly includes: a first flexure coupled between a first end of the piezoelectric stack and an actuator case containing the piezoelectric stack; a second flexure coupled between a second end of the piezoelectric stack and one side of the lever; A semiconductor substrate processing apparatus comprising: <Application example 5> The semiconductor substrate processing apparatus according to Application Example 3, (a) the showerhead module adjustment mechanism includes three actuator assemblies configured to induce movement of the showerhead module in two tilt directions and one axial translation; (b) an end of the lever opposite the piezoelectric stack causes movement of an adjustment screw coupled to a top plate of a bellows assembly; (c) an end of the lever opposite the piezoelectric stack acts on a ball joint of the adjustment screw through a socket groove; (d) the showerhead module is attached to the top plate of the bellows assembly. (e) the lever fulcrum limits lateral and vertical translation of the lever; (f) the combined thermal expansion of the upper flexure, flexure mount, and actuator case matches the thermal expansion of the piezoelectric stack; or (g) the showerhead module adjustment mechanism dynamically adjusts a tilt of the faceplate of the showerhead module over a range of approximately 3 milliradians. <Application Example 6> The semiconductor substrate processing apparatus according to Application Example 1, the showerhead module adjustment mechanism dynamically adjusts a position of a faceplate of the showerhead module with a resolution better than 0.15 milliradians. <Application Example 7> 1. A showerhead module adjustment mechanism for supporting a showerhead module within a top plate of a semiconductor substrate processing apparatus, comprising: A showerhead module adjustment mechanism dynamically operable to adjust the planarization of a faceplate of the showerhead module relative to an upper surface of a substrate pedestal module adjacent the faceplate in the semiconductor substrate processing apparatus. <Application Example 8> The showerhead module adjustment mechanism according to application example 7, A showerhead module adjustment mechanism comprising at least one actuator assembly that enables dynamic movement of the showerhead module in at least one tilt direction. <Application Example 9> The showerhead module adjustment mechanism according to application example 8, The at least one actuator assembly further comprises: a lever that mechanically amplifies the displacement of the piezoelectric stack; a blade-like flexure that serves as a lever fulcrum and connects the lever to an actuator case; a shower head module adjustment mechanism including: <Application Example 10> The showerhead module adjustment mechanism according to application example 9, a first flexure coupled between a first end of the piezoelectric stack and an actuator case containing the piezoelectric stack; a second flexure coupled between a second end of the piezoelectric stack and one side of the lever; The showerhead module adjustment mechanism, wherein the first flexure and the second flexure are configured to relieve stress on the piezoelectric stack. <Application Example 11> The showerhead module adjustment mechanism according to application example 9, further comprising: (a) three actuator assemblies configured to induce movement in two tilt directions and translation in one axial direction of the showerhead module; (b) an end of the lever opposite the piezoelectric stack causing movement of an adjustment screw coupled to a top plate of a bellows assembly; (c) the end of the lever opposite the piezoelectric stack acts on a ball joint of the adjustment screw through a socket groove; (d) the showerhead module is attached to the top plate of the bellows assembly; (e) the lever fulcrum limits lateral and vertical translation of the lever; (f) the combined thermal expansion of the upper flexure, flexure mount, and actuator case matches the thermal expansion of said piezoelectric stack; or (g) the showerhead module adjustment mechanism dynamically adjusts the tilt of the faceplate of the showerhead module over a range of approximately 3 milliradians; A showerhead module adjustment mechanism comprising: <Application Example 12> The showerhead module adjustment mechanism according to application example 7, a showerhead module adjustment mechanism that dynamically adjusts the position of the faceplate of the showerhead module with a resolution better than 0.15 milliradians. <Application Example 13> The showerhead module adjustment mechanism according to application example 9, The at least one actuator assembly further includes an upper flexure coupled between a top end of the piezoelectric stack and an actuator case encasing the piezoelectric stack. <Application Example 14> The showerhead module adjustment mechanism according to application example 8, The at least one actuator assembly further comprises: a lever that mechanically amplifies the displacement of the piezoelectric stack; a ball and socket joint coupled to the lever and a bottom end of the piezoelectric stack; an upper flexure coupled between a top end of the piezoelectric stack and an actuator case containing the piezoelectric stack; a shower head module adjustment mechanism including: <Application Example 15> 1. A current-carrying mechanism for adjusting a showerhead used in a deposition apparatus for processing a semiconductor substrate, comprising: An energization mechanism that adjusts the showerhead in one, two, or three degrees of freedom in less than one second. <Application Example 16> The current-carrying mechanism according to Application Example 15, Three independent actuator assemblies are used to provide three degrees of freedom, two tilt directions and one linear axial direction, of the energized mechanism. <Application Example 17> The current-carrying mechanism according to Application Example 16, Each actuator assembly is a combination of a piezoelectric stack and a lever having a blade-like flexure as a fulcrum, the lever being configured to amplify the displacement of the piezoelectric stack, an energized mechanism. <Application Example 18> The current-carrying mechanism according to Application Example 17, further comprising: An energizing mechanism comprising at least one coarse screw adjuster and at least one fine / dynamic actuator assembly to allow the showerhead to be both manually and dynamically adjusted. <Application Example 19> The current-carrying mechanism according to Application Example 17, An energization mechanism in which flexures are positioned on either end of the piezoelectric stack to allow kinematic movement of the piezoelectric stack while relieving stress on the piezoelectric stack. <Application Example 20> The current-carrying mechanism according to Application Example 17, (a) a ball and socket joint is disposed at one end of the piezoelectric stack for attaching the piezoelectric stack to the lever, the ball and socket joint being configured as a Gothic arch type geometry to reduce Hertzian stresses and wear; (b) the coefficient of thermal expansion (CTE) of materials of the current-carrying mechanism and the length of each material are selected to minimize variation in position with temperature; (c) a first flexure is disposed between the piezoelectric stack and an actuator case encasing the piezoelectric stack, and a second flexure is disposed between the piezoelectric stack and the lever, the second flexure being a blade-like flexure fabricated using direct metal laser sintering (DMLS) or other rapid prototyping techniques; (d) a position sensor is incorporated into the actuator to enable closed-loop feedback control to detect a non-functioning actuator; or (e) An energization mechanism in which one or two independent actuators are used to provide one or two degrees of freedom, the degrees of freedom being selected from two tilt directions and one linear axial direction.

Claims

1. 1. An actuator assembly for providing an adjustment mechanism for a showerhead within a substrate processing chamber, comprising: at least one piezoelectric stack, the at least one piezoelectric stack being dynamically operable to adjust at least one gap distance related to parallelism of the faceplate relative to an upper surface of a substrate pedestal adjacent to the faceplate of the showerhead; a lever coupled to each of the at least one piezoelectric stack and configured to mechanically amplify a displacement of the coupled at least one piezoelectric stack, the lever having a first end and a second end, the lever configured to be mechanically coupled to each of the at least one piezoelectric stack on the first end and coupled to the showerhead on the second end to displace the showerhead in at least one tilt direction of the showerhead; An actuator assembly comprising:

2. 2. The actuator assembly of claim 1, further comprising: An actuator assembly comprising at least one in-situ sensor that measures the at least one gap distance of the face plate relative to the top surface of the substrate pedestal.

3. 3. The actuator assembly of claim 2, The actuator assembly, wherein the at least one in-situ sensor includes at least one sensor selected from sensors including a laser interferometer, a linear variable differential transformer, and one or more strain gauge sensors.

4. 2. The actuator assembly of claim 1, further comprising: An actuator assembly comprising a lever pivot point coupled to the lever and located between the first end and the second end of the lever.

5. 5. An actuator assembly according to claim 4, comprising: An actuator assembly, wherein the lever pivot point comprises a blade-like flexure device that functions as a frictionless fulcrum based on elastic deformation of a solid material.

6. 5. An actuator assembly according to claim 4, comprising: the lever pivot point is located on a side of the lever opposite a contact point between the first end of each of the at least one piezoelectric stack and the lever.

7. 2. The actuator assembly of claim 1, further comprising: an actuator assembly comprising: a socket disposed at the second end of the lever, the socket acting on a ball joint coupled to the showerhead to dynamically move the showerhead in the at least one tilted direction;

8. 2. The actuator assembly of claim 1, and an actuator assembly, wherein the parallelism of the faceplate of the showerhead relative to the top surface of the substrate pedestal is adjusted from outside the substrate processing chamber in which the showerhead is located, without breaking a constant level of vacuum in the substrate processing chamber.

9. 2. The actuator assembly of claim 1, The actuator assembly is configured to dynamically adjust a position of the faceplate of the showerhead with a resolution of less than 0.15 milliradians.

10. 2. The actuator assembly of claim 1, An actuator assembly, wherein the lever has a gain ratio between 2:1 and 20:

1.

11. 2. The actuator assembly of claim 1, An actuator assembly, wherein the lever has a gain ratio of 6.5:

1.

12. 2. The actuator assembly of claim 1, An actuator assembly, wherein each of the at least one piezoelectric stack comprises a material that increases in length substantially linearly with increasing applied voltage.

13. 2. The actuator assembly of claim 1, further comprising: a first flexure coupled between a first end of the piezoelectric stack and an actuator case containing the piezoelectric stack; a second flexure coupled to a second end of the piezoelectric stack and to one side of the lever, the first flexure and the second flexure configured to relieve stress on each of the at least one piezoelectric stack; An actuator assembly comprising:

14. 1. A mechanism for adjusting a faceplate of a showerhead in a substrate processing chamber, comprising: at least one actuator assembly for enabling dynamic movement of the showerhead in at least one tilt direction, each of the at least one actuator assembly comprising: at least one piezoelectric stack, each of the at least one piezoelectric stack including a material that increases in length substantially linearly with increasing applied voltage; a lever having a first end and a second end coupled to a respective end of the at least one piezoelectric stack at the first end for mechanically amplifying a displacement of the piezoelectric stack, and coupled to the showerhead on the second end for displacing the showerhead in the at least one tilted direction, the lever configured to align a faceplate of the showerhead substantially parallel to a top surface of a substrate pedestal adjacent the faceplate; A mechanism comprising:

15. 15. The mechanism of claim 14, further comprising:

1. A mechanism comprising: a blade-like flexure device that functions as a frictionless fulcrum based on elastic deformation of a solid material, the blade-like flexure device being coupled to the lever and positioned between the first end and the second end of the lever.

16. 15. The mechanism of claim 14, Each of the at least one actuator assembly is associated with at least one degree of freedom of movement.

17. 15. The mechanism of claim 14, further comprising: a mechanism comprising at least one in-situ sensor that measures the at least one gap distance of the face plate relative to the top surface of the substrate pedestal.

18. 15. The mechanism of claim 14, further comprising: a mechanism including a socket on the second end of the lever that acts on a ball joint coupled to the showerhead to dynamically move the showerhead in at least one tilted direction.

19. 1. An actuator assembly for providing an adjustment mechanism for a showerhead within a substrate processing chamber, comprising: at least one piezoelectric stack dynamically operable to adjust parallelism of the showerhead faceplate relative to an upper surface of a substrate pedestal adjacent the faceplate; a lever coupled to each of the at least one piezoelectric stack, the lever being mechanically coupled to each of the at least one piezoelectric stack on one end and coupled to the showerhead on an opposite end to mechanically amplify a displacement of the coupled at least one piezoelectric stack and displace the showerhead in at least one tilt direction of the showerhead; at least one in-situ sensor that measures a gap distance of the faceplate of the showerhead relative to a top surface of the substrate pedestal to determine the parallelism; An actuator assembly comprising:

20. 20. The actuator assembly of claim 19, further comprising: a lever pivot point comprising a blade-like flexure device that acts as a frictionless fulcrum based on elastic deformation of a solid material; a socket coupled to the opposite end of the lever for acting on a ball joint coupled to the showerhead to dynamically move the showerhead in at least one tilting direction; An actuator assembly comprising:

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