Patent Description:
The present disclosure relates generally to area-selective atomic layer deposition for the nanofabrication of <NUM>-D thin-films for printable and customizable devices.

Area-selective atomic layer deposition (AS-ALD) is a method for selectively depositing ALD thin-films for devices including, for example, thin film transistors in an additive, bottom-up manner without the need for lithography and top-down etching processes. In AS-ALD, an inhibition material is first patterned onto a working surface of a build substrate to passivate surface reaction sites and inhibit growth on the underlying surface of the build substrate. A thin-film material, such as a metal oxide film, is then deposited on the growth areas of the working surface not covered by the inhibition material, typically by atomic layer deposition (ALD). By taking advantage of the inherent self-limiting and surface reaction mechanism of ALD, the patterned inhibition material can prevent precursor ligands from adhering to the substrate surface.

Atomic layer deposition (ALD) is a thin-film deposition technique that is capable of conformally coating a surface of a build substrate-which may be an ultra-high-aspect ratio substrate-with a nanometer-scale film of an ALD material one atomic layer at a time. ALD involves sequentially exposing a designated portion of the build substrate to various ALD precursor gases. Each of the ALD precursor gases includes reactive ligands that participate in a self-limiting surface reaction to chemically deposit an atomic monolayer of the reacted precursor gases. The two atomic monolayers that are derived alternately from the ALD precursor gases together produce a single atomic layer of the ALD material film upon completion of their reaction. As such, the growth rate and thickness of the ALD material film can be controlled by varying the number of ALD cycles performed and, thus, the number of atomic layers of the ALD material that are chemically-deposited in a layer-by-layer fashion. Indeed, the ALD material film exhibits a linear growth rate; that is, the thickness of the film is proportional to the number of ALD cycles performed. The material that can be deposited by ALD can range from oxides to nitrides, sulfides, carbides, and/or metals by exploiting the self-limiting binary chemical reactions of ALD.

Spatial atomic layer deposition (SALD) is a specific version of ALD where the ALD cycles are spatially controlled by exposing the build substrate to different precursor gas zones rather than a conventional temporally controlled ALD process where long purging of the precursor gases in a static chamber is required. In SALD, the time-consuming purge step of conventional ALD is not practiced, which expediates the process by up to three orders of magnitude, without sacrificing the self-limiting, conformal growth of the ALD material film. As a result, the net deposition rate of SALD is much greater compared to conventional ALD, which enables higher throughput in a shorter amount of time. SALD deposition processes may be performed in conjunction with the prior patterning of the inhibition material during AS-SALD to fabricate <NUM>-D devices in a bottom-up manner without the need for lithography and top-down etching processes. The thin-film <NUM>-D devices may even include multiple films of dissimilar materials to stack thin film layers for device fabrication.

AS-ALD with 3D printing technology has been practiced using drop-on-demand inkjet printing to deposit inhibition material patterns to inhibit growth of ALD films such as zinc oxide (ZnO) and aluminum-doped-zinc oxide (AZO). However, inkjet printing uses thermal or acoustic pulses in formation and ejection of the droplets which makes it difficult to control the droplet diameter and ink volume for higher resolution. Traditional inkjet printing has a limited spatial resolution of approximately <NUM>, and, therefore, is generally not suitable for nanofabricating thin-film devices that may require nanoscale resolution. Furthermore, by having to transfer the build substrate between dedicated substrate plates for each of the ink jet printing and ALD stations, throughput is decreased due to the down time associated with the transfer process, and the probability for realignment errors causes the repeatability and consistency of the process to suffer. For example, if an inhibition material pattern is printed on a build substrate, and the build substrate has to be removed, transferred, and re-supported at the ALD station, the ability to precisely align the printed inhibition layer pattern with the pattern to be deposited at the ALD station is a difficult endeavor.

The present disclosure describes an integrated electrohydrodynamic jet printing (E-jet printing) and spatial atomic layer deposition (SALD) system for conducting nanofabrication of customizable <NUM>-D thin-film devices. E-jet printing uses an electric field-instead of the thermal bubble or piezo acoustic actuation used in drop-on-demand ink jet printing-to expel jetted liquid drops containing an inhibition polymer from a nozzle orifice that can be submicron sized. The smaller nozzle coupled with electric field actuation can achieve more than three orders of magnitude drop volume reduction compared to ink jet printing and sub <NUM>-nm jetted drops and printed lines. When used to print inhibition material patterns as part of AS-ALD, E-jet printing enables patterns up to spatial resolutions of <NUM> or less to be printed in the X- and Y- plane, which is a notably higher resolution than is practically possible with ink jet printing. Combined with AS-SALD, the high-resolution printing made possible by E-jet printing widens the applicability of AS-ALD to enable the nanofabrication of customizable <NUM>-D thin-film devices.

Moreover, by integrating E-jet printing and SALD into one single platform in which the same substrate plate is conveyed between the two stations along a conveyor, the build substrate can be shuttled or conveyed back-and-forth between the two stations without having to be removed from the substrate plate. The overall process can thus be performed with less downtime and more precise alignment of the build substrate at each station. The use of E-jet printing to print the inhibition material pattern, as opposed to ink jet printing, and the automated conveyance of the build substrate between the E-jet and SALD stations on the same substrate plate can produce thin-film devices, such as printed electronic circuits, on the sub-<NUM> resolution scale with enhanced precision. The disclosed E-jet/SALD integrated system is also less cumbersome and more customizable than other conventional thin-film manufacturing techniques such as photolithography combined with top-down etching. Furthermore, inhibitor materials that are easily soluble in organic solvents may be removed by exposing the build substrate to solvent vapors in the SALD station or at some other location. In this way, ALD films can be printed and stacked in-situ in a <NUM>-D additive manner.

Document <CIT> relates to an atomic-layer-deposition process for forming a patterned thin film comprising providing a substrate, applying a deposition inhibitor material to the substrate, wherein the deposition inhibitor material is an organic compound or polymer; and patterning the deposition inhibitor material either after step (b) or simultaneously with applying the deposition inhibitor material to provide selected areas of the substrate effectively not having the deposition inhibitor material. An inorganic thin film material is substantially deposited only in the selected areas of the substrate not having the deposition inhibitor material.

Document <CIT> relates to methods and devices for electrohydrodynamic (E-jet) printing. The methods relate to sensing of an output current during printing to provide control of a process parameter during printing. The sensing and control provides E-jet printing having improved print resolution and precision compared to conventional open-loop methods. Also provided are various pulsing schemes to provide high frequency E-jet printing, thereby reducing build times by two to three orders of magnitude. A desktop sized E-jet printer having a sensor for real-time sensing of an electrical parameter and feedback control of the printing is provided.

According to one aspect of the disclosure, there is provided an integrated electrohydrodynamic jet printing and spatial atomic layer deposition system for conducting nanofabrication of claim <NUM>. The system includes:.

According to various embodiments, the integrated electrohydrodynamic jet printing and spatial atomic layer deposition system may further include any one of the following features or any technically-feasible combination of some or all of these features:.

According to another aspect of the disclosure, there is provided an integrated electrohydrodynamic jet printing and spatial atomic layer deposition system for conducting nanofabrication of claim <NUM>. The system includes:.

According to another aspect of the disclosure, there is provided a method of conducting area-selective atomic layer deposition of claim <NUM>. The method includes the steps of:.

Example embodiments will hereinafter be described in conjunction with the appended drawings, wherein like designations denote like elements, and wherein:.

An integrated electrohydrodynamic jet printing (E-jet printing) and spatial atomic layer deposition (SALD) system <NUM> is disclosed. Several views of the integrated E-jet printing and SALD system <NUM> are shown in <FIG>. As depicted, the E-jet printing and SALD system <NUM> includes an E-jet printing station <NUM>, a SALD station <NUM>, a cooling station <NUM>, a heatable substrate plate <NUM> with a vacuum chuck used to hold a build substrate in place, a motion actuator <NUM>, and a conveyor <NUM>. The integrated E-jet printing and SALD system <NUM> can perform area-selective atomic layer (AS-ALD) deposition onto a working surface <NUM> of a build substrate <NUM> (<FIG> and <FIG>), such as a silicon wafer or a substrate composed of some other an inorganic or organic material, for the nanofabrication of customizable <NUM>-D thin-film devices including <NUM>-D printed thin-film electronics. With careful pattern design and printing of an inhibition material at the E-jet printing station <NUM>, and automated conveyance of the common substrate plate <NUM> between the E-jet printing and the SALD stations <NUM>, <NUM>, thin-film devices including electronic circuit components having a sub-<NUM> spatial resolution and Z-axis spatial resolution on the atomic scale (A-resolution by ALD) can be fabricated. The integration of the E-jet printing station <NUM> and the SALD station <NUM> enhances production throughput and minimizes the probability that the build substrate <NUM> carried by the substrate plate <NUM> will be misaligned at either of the stations <NUM>, <NUM>.

The E-jet printing station <NUM> includes an E-jet printing nozzle <NUM> mounted to an E-jet bridge <NUM> that contains a pair of horizontal rails <NUM>, each of which extends between opposed upstanding legs 34a, 34b that are supported on a stand surface, and a transverse rail 32t that extends between the horizontal rails <NUM>. The E-jet printing nozzle <NUM>, which is shown best in <FIG> and <FIG>, is secured to a mounting plate that, in turn, is secured to the transverse rail 32t. The E-jet printing nozzle <NUM> expels jetted liquid droplets from a polarizable liquid through an electric field onto the working surface <NUM> of the build substrate <NUM> at high resolution within a printing window <NUM>. The electric field, more specifically, induces flow in the polarizable liquid and, when strong enough, the surface charge repulsion experienced by the polarizable liquid at a pipette tip of the nozzle <NUM> ejects the jetted liquid droplets from the nozzle <NUM> towards the working surface <NUM> of the build substrate <NUM> in a controlled and designated pattern.

The jetted liquid droplets ejected from the E-jet printing nozzle <NUM> may contain a solvent only or a solution that includes an inhibition material for patterned printing. An inhibition material that may be expelled from the E-jet printing nozzle <NUM> within the jetted liquid droplets for purposes of AS-ALD may be any polymer that lacks the required reaction sites to which the ligands of the ALD precursor gases may bond; in other words, the polymer is unreactive or chemically inert with regards to the ALD precursor gases. Such polymer materials obstruct the ALD precursor gases from binding to the underlying working surface <NUM> beneath the inhibition material at a later time yet allow the selective ALD growth on the working surface <NUM> of the build substrate <NUM> that is not covered by the inhibition material pattern. Several examples of suitable polymers that may be employed as the inhibition material include poly(methyl methacrylate) (PMMA) and poly(vinylpyrrolidone) (PVP). These polymers are typically dissolved or dispersed in a solvent such as water, dimethyl sulfoxide (DMSO), or anisole. If the liquid droplets contain a solvent only, the solvent may include N-Methyl-Pyrrolidone (NMP).

In addition to the E-jet printing nozzle <NUM>, the E-jet printing station <NUM> may include a camera <NUM> and, optionally, as shown in <FIG>, an AFM (atomic force microscope) <NUM>. The camera <NUM> allows for viewing and recording of the jetted liquid droplets being expelled towards the build substrate <NUM>, including the process of printing a pattern of the inhibition material onto the working surface <NUM> if the droplets include such a polymer. The AFM <NUM> allows for measuring the dimensions of the printed patterns created by the E-jet printing nozzle <NUM> and to analyze the morphology of the selectively grown ALD film. The AFM <NUM> includes a cantilevered tip that scans or probes the build substrate and interacts with the inhibition material patter and/or the ALD material film. The motion and deflections of the tip caused by those interactions are detected, often by a laser optical system or piezoelectric sensors, and imagery is produced of the profile of the inhibition material layer and/or the ALD material film at nanometer-scale resolution of less. While the AFM <NUM> is shown here as part of the E-jet printing station <NUM>, the AFM <NUM> does not necessarily have to be part of the E-jet printing station <NUM> as it can be located elsewhere in the system <NUM>. Additionally, and while not shown here, the E-jet printing nozzle <NUM> may be connected to a signal generator and amplifier that delivers controlled voltage pulses to the nozzle <NUM> to activate droplet formation and expulsion.

The SALD station <NUM> operates to conformally coat the regions of the working surface <NUM> of the build substrate <NUM> not inhibited by the inhibition material pattern with an ultra-high aspect ratio sub-nanometer precision film of the ALD material one atomic layer at a time. The SALD station <NUM> includes a frame <NUM>, a bridge <NUM>, and a zoned ALD precursor gas distributor <NUM>. The frame <NUM> includes first and second upstanding adjustable support legs 48a, 48b that are spaced apart from one another above the stand surface. The first and second upstanding support legs 48a, 48b support the bridge <NUM> horizontally in an elevated position. The bridge <NUM> comprises an elongated body <NUM> that carries the zone ALD precursor gas distributor <NUM>. The elongated body <NUM> may be stationarily or tiltably supported on the upstanding support legs 48a, 48b. If tiltably supported, the elongated body <NUM> may be tiltable about each of its long and short axes and, as such, would have the potential to control the tilt of the ALD precursor gas distributor <NUM> in a corresponding manner as needed. In the embodiment shown here, the elongated body <NUM> is an elongated plate <NUM> that defines a central opening <NUM> through which the zoned ALD precursor gas distributor <NUM> is supported.

The zoned ALD precursor gas distributor <NUM>, which is shown best in <FIG> and <FIG>, discharges linear zone-separated first and second ALD precursor gases towards the substrate plate <NUM> that retains the build substrate <NUM> within a deposition window <NUM> where SALD growth is directed. The first and second ALD precursor gases used during SALD processing may vary depending on the composition of the ALD material film being deposited. The first ALD precursor gas may, for example, be an organometallic gas, and the second ALD precursor gas may be an oxidant gas. In one implementation of SALD, the ALD material film grown on the build substrate may comprise a metal oxide such as zinc oxide (ZnO), tin oxide (SnO<NUM>), or aluminum oxide (Al<NUM>O<NUM>). To deposit ZnO, SnO<NUM>, or Al<NUM>O<NUM> by SALD, the first ALD precursor gas (an organometallic gas) may be diethylzinc (DEZ) for ZnO, tetrakis(dimethylamido)tin (TDMASn) for SnO<NUM>, and dimethylaluminum isopropoxide (DMAI) or trimethyl aluminum (TMA) for Al<NUM>O<NUM>, and the second ALD precursor gas (an oxidant gas) in each instance may be distilled water. The inert gas used to separate and isolate the first and second ALD precursor gases may be nitrogen (N<NUM>). Of course, other ALD precursor gases and inert gases may be employed to form any of the aforementioned metal oxides films as well as other compositions of the ALD material. The SALD apparatus described herein and the ways in which the SALD apparatus is used are not limited to any particular ALD precursor gases, inert gases, or compositions of the deposited ALD material film.

The zoned ALD precursor gas distributor <NUM> includes a gas manifold <NUM> and a depositor head <NUM>. The gas manifold <NUM> is fluidly connected above the elongated plate <NUM> to sources (not shown) of the first ALD precursor gas, the second ALD precursor gas, and the inert gas, and is also fluidly connected to a vacuum source to provide suction for the exhaust of unreacted precursor gases and the inert gas. The gas manifold <NUM> extends through the central opening <NUM> to a delivery end <NUM> of the manifold <NUM> disposed below the elongated plate <NUM>. The depositor head <NUM> is secured to the delivery end <NUM> of the gas manifold <NUM> below the elongated plate <NUM> by fasteners or another type of joint, although in other implementations the gas manifold <NUM> and the depositor head <NUM> may be integrally formed. The depositor head <NUM> may be constructed from stainless steel or some other electrically-conductive and chemically-inert material that does not react adversely with the precursor gases during delivery. Mass flow controllers may be attached to the gas manifold <NUM> or they may be more remotely located to control the flow of the first and second ALD precursor gases as well as the flow of the inert gas.

The depositor head <NUM> has an active surface <NUM> configured to discharge at least one linear flow of the first ALD precursor gas <NUM>, at least one linear flow of the second ALD precursor gas <NUM>, and at least one linear flow of the inert gas <NUM> that separates the linear flow of the first ALD precursor gas <NUM> and the linear flow of the second ALD precursor gas <NUM>, as shown schematically in <FIG>. The linear flow of the first ALD precursor gas <NUM>, the linear flow of the second ALD precursor gas <NUM>, and the linear flow of the inert gas <NUM> are parallel to each other and extend in a first direction A (into the page). Since the linear flows of the ALD precursor gases <NUM>, <NUM> are separated and flow isolated by the linear flow of the inert gas <NUM>, the linear flow of the first ALD precursor gas <NUM> and the linear flow of the second ALD precursor gas <NUM> establish first and second ALD precursor gas zones, respectively, while the linear flow of the inert gas <NUM> establishes an inert gas curtain. More than one linear flow of the first ALD precursor gas and more than one linear flow of the second ALD precursor gas may be delivered from the active surface <NUM> of the depositor head <NUM> so long as the linear flows of the first and second ALD precursor gases alternate across the active surface <NUM> with each pair of adjacent linear flows of the first and second ALD precursor gases being separated by a linear flow of the inert gas to ensure the establishment of respective ALD precursor gas zones.

In one specific embodiment, as shown in <FIG> and often referred to as a "showerhead" delivery arrangement, the active surface <NUM> of the depositor head <NUM> may define a central elongated channel <NUM> that discharges a linear flow of the first ALD precursor gas. The active surface <NUM> also defines a second elongated channel <NUM> on one side of the central elongated channel <NUM> and a third elongated channel <NUM> on the other side of the central elongated channel <NUM>. Each of the second and third elongated channels <NUM>, <NUM> extends parallel to the central elongated channel <NUM> and discharges a linear flow of the second ALD precursor gas. And, to keep the linear flows of the first and second ALD precursor gases isolated into their respective ALD precursor gas zones, a fourth elongated channel <NUM> is defined by the active surface <NUM> between the central elongated channel <NUM> and the second elongated channel <NUM> that discharges a linear flow of the inert gas, and a fifth elongated channel <NUM> is defined by the active surface <NUM> between the central elongated channel <NUM> and the third elongated channel <NUM> that discharges a linear flow of the inert gas. Each of the fourth and fifth elongated channels <NUM>, <NUM> extends parallel to each of the central, first, and second elongated channels <NUM>, <NUM>, <NUM> and is bound on each side by a pair of elongated vacuum ports 82a, 82b, 82c, 82d. The vacuum ports 82a, 82b, 82c, 82d communicate with exhaust lines to remove the inert gas any un-reacted ALD precursors gases. All of the elongated channels <NUM>, <NUM>, <NUM>, <NUM>, <NUM> all run parallel to each other and extend along the first direction A.

The active surface <NUM> of the depositor head <NUM> also defines a continuous peripheral border channel <NUM> that surrounds and encloses all of the other channels <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. The peripheral border channel <NUM> includes first and second elongated side channel portions 84a, 84b that run parallel to the other elongated channels <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and, thus, extend in the first direction A. Additionally, the peripheral border channel <NUM> includes first and second elongated bridge channel portions 84c, 84d that run perpendicular to the elongated channels <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and connect with the elongated side channel portions 84a, 84b to complete the continuous track of the peripheral border channel <NUM>. The peripheral border channel <NUM> discharges a flow of the inert gas and, more specifically, the four channel portions 84a, 84b, 84c, 84d of the peripheral border channel <NUM> discharge corresponding linear flows of the inert gas. In that regard, a linear flow of the inert gas is located on each side of the second and third elongated channels <NUM>, <NUM> opposite the fourth and fifth elongated channels <NUM>, <NUM>, respectively, such that an inert gas curtain is present on each side of the second ALD precursor gas zones established by the linear flows of the second ALD precursor gas discharged from the second and third elongated channels <NUM>, <NUM>.

Because of the zone-separated nature of linear flows of the ALD precursor gases, oscillating the build substrate <NUM> in a second direction B transverse to the first direction A alternately exposes the working surface <NUM> to the first and second ALD precursor gas zones. During each cycle of exposure to both the first and second ALD precursor gas zones, the two ALD precursor gases react to form an ALD material layer that constitutes all or part of the ALD material film. Indeed, the number of atomic layers of the ALD material that are deposited, and thus the corresponding thickness of the ALD material film grown on the working surface <NUM> of the build substrate <NUM>, depends on the number of times the working surface <NUM> is exposed to both the first and second ALD precursor gases by transverse movement through the linear first and second ALD precursor gas zones. The oscillation of the build substrate <NUM> beneath the depositor head <NUM> of the zoned ALD precursor gas distributor <NUM> is effectuated by the motion actuator <NUM> as will be described in more detail below.

The SALD station <NUM> may include other components in addition to the frame <NUM>, the bridge <NUM>, and the zoned ALD precursor gas distributor <NUM>. For example, a series of gap detection sensors <NUM> may be mounted to depositor head <NUM> to measure the distance between the active surface <NUM> of the depositor head <NUM> and the confronting surface of the substrate plate <NUM>, as illustrated in <FIG>. Each of the gap detection sensors <NUM> may be a capacitive sensor, a photoelectric sensor, an inductive sensor, or a laser sensor. The gap detection sensors <NUM> can measure the gap between the depositor head <NUM> and the substrate plate <NUM> in real time and can input measurement data into a controller that, in turn, can adjust the distance between the depositor head <NUM> and the substrate plate <NUM> by, for example, tilting the depositor head <NUM> via the elongated plate <NUM> and/or by tilting the substrate plate <NUM> that retains the build substrate <NUM>. The SALD station <NUM> may also include gas lines, vacuum lines, and a chiller to store and cool the first and/or second ALD precursor gases in the event the gas or gases are too volatile at room temperature.

The cooling station <NUM> is located between the E-jet printing station <NUM> and the SALD station <NUM>. The cooling station <NUM> includes at least one duct <NUM> that is in fluid communication with a fan <NUM> that forces a gas, preferably air, through the duct <NUM> at ambient temperature (i.e., <NUM> -<NUM>) or below ambient temperature. The gas exiting the duct(s) <NUM> establishes a cooling gas zone CZ. Upon exiting the SALD station <NUM>, in which the heatable substrate plate <NUM> and the build substrate <NUM> are typically heated in order to carry out the SALD process, the build substrate <NUM> may pass through, either continuously or it may be held within the cooling gas zone CZ for a period of time, to reduce the temperature of the build substrate <NUM>, particularly if the build substrate <NUM> is being delivered to the E-jet printing station <NUM> for patterned printing.

The heatable substrate plate <NUM> carries and supports the build substrate <NUM> in both the E-jet printing station <NUM> and the SALD station <NUM>. In other words, the heatable substrate plate <NUM> is a common substrate plate used in both stations <NUM>, <NUM>, and to that end the heatable substrate plate <NUM> satisfies the operating conditions for each station <NUM>, <NUM> while also being transportable therebetween. The heatable substrate plate <NUM> includes a support surface <NUM> that retains the build substrate <NUM>. The support surface <NUM> defines one or more vacuum holes <NUM> (<FIG>) that communicate with a vacuum source through a vacuum chuck to create suction. This suction retains and holds the build substrate <NUM> in a defined position on the substrate plate <NUM> as needed for inhibition material printing at the E-jet printing station <NUM> and conformal SALD thin-film growth at the SALD station <NUM>. The heatable substrate plate <NUM> may include an electric heater, such as a flexible polyamide heater attached to an exterior of the plate <NUM>, so that the plate <NUM> can be heated to temperatures of <NUM>° to <NUM>-the temperature varies depending on the composition of the ALD precursor gases and the desired composition and properties of the ALD material film being grown-for SALD processing, although other heating mechanisms may certainly be employed. The heatable substrate plate <NUM> may be constructed from a nickel-iron alloy. One such alloy that is suitable here is FeNi36 or Invar. Additionally, as shown here, the substrate plate <NUM> may define a plurality of locator shaft openings <NUM> that traverse the plate <NUM> from the support surface <NUM> to a back surface <NUM> of the plate <NUM> opposite the support surface <NUM>.

The motion actuator <NUM> supports the heatable substrate plate <NUM> and is controllable with standard controllers and programming logic to move the substrate plate <NUM>, preferably in three dimensions. The motion actuator <NUM> includes a base plate <NUM>, a plurality of linear actuators <NUM>, and at least one linear motion stage <NUM>, as shown best in <FIG> and <FIG>. The base plate <NUM> is positioned below the substrate plate <NUM> and is disposed on a central block <NUM> that is either integral with the base plate <NUM> or secured to the base plate <NUM> by, for example, one or more fasteners. The base plate <NUM> defines a plurality of openings <NUM> that traverse the base plate <NUM> from a top surface <NUM> of the plate <NUM> to a bottom surface <NUM> of the plate <NUM> opposite the top surface <NUM>. The base plate <NUM> may also include a plurality of threadably-supported locator shafts <NUM> that are aligned with and receivable through the plurality of locator shaft openings <NUM> defined in the substrate plate <NUM>. The locator shafts <NUM> may be used to achieve initial positioning of the substrate plate <NUM> relative to the base plate <NUM> or to maintain the position of the plates <NUM>, <NUM> when the system <NUM> is off-line. The locator shafts <NUM>, however, are generally not secured to the substrate plate <NUM> with nuts or other threaded engagement devices, although they may extend freely through the locator shaft openings <NUM>, when the substrate plate <NUM> is engaged in printing or ALD material film growth at the E-jet printing stage <NUM> and the SALD stage <NUM>, respectively.

The plurality of linear actuators <NUM> are operable to adjust the spacing between the substrate plate <NUM> and the base plate <NUM> and to also control the tilt of the substrate plate <NUM>. Each of the plurality of linear actuators <NUM> includes a motor <NUM> and an actuation rod <NUM>. The actuation rod <NUM> of each actuator <NUM> is displaceable in both a positive (forward or extending) and negative (rearward or retracting) direction by its respective motor <NUM> which, for example, is preferably a stepper motor. Each of the motors <NUM> used to drive linear displacement of its respective linear actuation rods <NUM> preferably has a step size or resolution of <NUM> or higher to enable precision guided linear displacement of the actuation rods <NUM>. The linear actuators <NUM> can be controlled as needed to adjust the vertical position and/or the tilt of the substrate plate <NUM> if needed at the E-jet printing station <NUM> and/or the SALD station <NUM> to ensure proper alignment with the E-jet printing nozzle <NUM> and/or the depositor head <NUM>, respectively. Commercially available actuator assemblies that include a motor and an actuator rod may be used including, for example, a linear motion stepper motor assembly from Haydon Kerk Pittman. While stepper motors and actuation rods are described here as being preferred implementations, it will be appreciated that other types of linear actuators and driving mechanisms may of course be employed to achieve the same functionality.

Each of the plurality of linear actuators <NUM> extend through one of the plurality of openings <NUM> defined in the base plate <NUM> and engages the back surface <NUM> of the support plate <NUM>. As shown here, for example, the motor <NUM> of each actuator <NUM> may be secured to the central block <NUM> of the motion actuator <NUM> below the base plate <NUM>, and the actuation rod <NUM> driven by each respective motor <NUM> may extend through the associated opening <NUM> of the base plate <NUM>. Tip ends of the actuation rods <NUM>, in turn, engage the back surface <NUM> of the support plate <NUM> at spaced engagement points and are actuatable individually or collectively to change the relative positioning of the substrate plate <NUM> relative to the base plate <NUM>.

The at least one linear motion stage <NUM> supports the central block <NUM> and commands movement of the base plate <NUM>, and by extension the substrate plate <NUM>, within a horizontal plane along two coordinate axes. The movement of the substrate plate <NUM> in by the linear motion stage(s) <NUM> in the horizontal plane, together with the ability to command both tilting movement of the substrate plate <NUM> and vertical movement of the substrate plate <NUM> in dimension orthogonal to the horizontal plane with the plurality of linear actuators <NUM>, enables the substrate plate <NUM> to be moved relative to the E-jet printing nozzle <NUM> and the depositor head <NUM> of the zoned ALD precursor gas distributor <NUM> when present at the E-jet printing station <NUM> and the SALD station <NUM>, respectively. As shown best in <FIG> and <FIG>, the at least one linear motion stage <NUM> may be an upper single-axis linear motion stage 120a and a lower single-axis linear motion stage 120b. Each of the upper and lower single-axis linear motion stages 120a, 120b controls movement along one axis of the two-dimensional horizontal plane. Each stage 120a, 120b includes a travel stand 122a, 122b and a mobile table 124a, 124b that is slidable fore and aft along the travel stand 122a, 122b in a machine dimension. The sliding movement of the mobile table 124a, 124b is effectuated by a linear drive motor housed within the travel stand 122a, 122b. In general, each of the upper and lower single-axis linear motion stages 120a, 120b preferably has sub-micron resolution, or minimum incremental movement, typically on the order of <NUM> to <NUM>, and a maximum travel speed of <NUM> meters per second, along with sub-micron repeatability and sub-<NUM>-micron horizontal and vertical straightness. One specific and commercially available linear motion stage that satisfies these performance characteristics is an Aerotech Pro <NUM> LM mechanical bearing linear motor stage.

The upper and lower single-axis linear motion stages 120a, 120b are stacked and mounted orthogonal to each other. In particular, the central block <NUM> upon which the base plate <NUM> is disposed is mounted to the mobile table 124a of the upper single-axis linear motion stage 120a by mechanical fasteners, and the travel stand 122a of the upper single-axis linear motion stage 120a is mounted to the mobile table 124b of the lower single-axis linear motion stage 120b by mechanical fasteners. Sliding linear movement of the mobile tables 124a, 124b can therefore be coordinated to move the substrate plate <NUM> anywhere within the horizontal plane. In another embodiment, and rather than employing two single-axis linear motion stages, the at least one linear motion stage <NUM> may be a two-axis linear motion stage, such as the Aerotech PlanarDL two axis, mechanical bearing, direct drive linear stage. A two-axis linear motion stage of this type can move in both the X and Y directions with high accuracy, resolution, and bidirectional repeatability, and can support the central block <NUM> in the same manner as described above.

The motion actuator <NUM> is coupled to the conveyor <NUM>, which extends and defines a linear travel path between the E-jet printing station <NUM> and the SALD station <NUM>. The conveyor <NUM> may be a linear actuator of any suitable type. For example, and referring now to <FIG>, the conveyor <NUM> may be a ball screw linear actuator that includes opposed linear guides 126a, 126b, a central guide track <NUM> that contains a rotatable threaded screw <NUM>, and an adapter plate <NUM> onto which the motion actuator <NUM> is mounted. The adapter plate <NUM> is slidably received on the central guide track <NUM>, while also being in threaded communication with the rotatable threaded screw <NUM> that extends within and along the central guide track <NUM>. In that regard, the adapter plate <NUM> is drivable in one linear direction along the length and travel path of the conveyor <NUM> by rotation of the screw <NUM> in a first rotational direction and, likewise, is drivable in a second linear direction along the length and travel path of the conveyor <NUM>, which is opposite the first linear direction, by rotation of the screw <NUM> in an opposite second rotational direction. The conveyor <NUM> may be any other type of linear actuator including a single axis linear motion stage similar to the ones described above in connection with the motion actuator <NUM> although a less accurate stage will likely suffice. By operation of the conveyor, the motion actuator <NUM> and, by extension, the common support plate <NUM>, can be conveyed between the E-jet printing station <NUM> and the SALD station <NUM>. This allows the substrate plate <NUM> and the build substrate <NUM> carried thereon to be conveyed between the printing window <NUM> of the E-jet printing nozzle <NUM> and the deposition window <NUM> of the depositor head <NUM> without having to remove the build substrate <NUM> from the substrate plate <NUM>.

The integrated electrohydrodynamic jet printing and spatial atomic layer deposition system <NUM> may be used to conduct area-selective atomic layer deposition. The AS-ALD process may be performed via an additive printing or a subtractive printing approach at the E-jet printing station <NUM>. Additive printing involves directly printing a pattern of the inhibition material onto the working surface <NUM> of the build substrate <NUM> to define a growth area in which no inhibition material is present and the ALD material film can be grown at the SALD station <NUM>. Subtractive printing, on the other hand, involves directing a solvent at a deposition layer of an inhibition material to displace a portion of the inhibition material so as to expose and define a growth area of the working surface <NUM> in which no inhibition material is present and the ALD material film can be grown at the SALD station <NUM>. Essentially, additive printing passivates the working surface <NUM> and subtractive printing activates the working surface <NUM> for ALD growth, but each nonetheless results in a deposited pattern of the inhibition material that defines a growth area. After the ALD material film is grown, at least some of the pattern of the inhibition material may be cured, thermally annealed, or partially removed. The curing, annealing, or removal of the inhibition material pattern may be integrated into the integrated electrohydrodynamic jet printing and spatial atomic layer deposition system <NUM> as an additional station along the travel path of the conveyor <NUM> between the E-printing station <NUM> and the SALD station <NUM> or it may be performed separate and apart from the system <NUM>.

Referring now to <FIG> and the top of <FIG>, an AS-ALD process that employs subtractive printing is described. In that process, the heatable substrate plate <NUM> that supports the build substrate <NUM> is positioned within the printing window <NUM> of the E-jet printing nozzle <NUM> of the E-jet printing station <NUM>. The build substrate <NUM> in this embodiment includes a pre-applied inhibition material deposition layer <NUM> such as a layer of PMMA. A pattern of a solvent, such as NMP, is then printed onto the inhibition material layer <NUM> of the build substrate <NUM> to selectively displace or remove a portion of the inhibition material layer to form a pattern <NUM> of the inhibition material. An ALD growth area <NUM> is thus defined on the working surface <NUM> by the inhibition material pattern <NUM> where the inhibition material coating has been displaced and, thus, is no longer present. Next, the heatable substrate plate <NUM> is conveyed away from the printing window <NUM> of the E-jet printing nozzle <NUM> and to the SALD station <NUM> by operation of the conveyor <NUM>. The substrate plate <NUM> is positioned within the deposition window <NUM> of the zoned ALD precursor gas distributor <NUM> and heated as needed to support the reaction between the first and second ALD precursor gases. Once in position, an ALD material film <NUM> is deposited layer-by-layer on the growth area by oscillating the build substrate <NUM> relative to the depositor head <NUM> and transverse to the first and second ALD precursor gas zones. After the ALD material film <NUM> has been deposited, the pattern of the inhibition material <NUM> may be exposed to solvent vapors or plasma to remove some or all of the inhibition material pattern <NUM>, if desired, and the substrate plate <NUM> may be conveyed away from the deposition window <NUM> of the zoned ALD precursor gas distributor <NUM> and brought to the cooling station <NUM> where the substrate plate <NUM> and the build substrate <NUM> are cooled. In other scenarios, rather than removing some or all of the inhibition material pattern <NUM>, some or all of the inhibition material pattern <NUM> may be cured with ultraviolet light or be thermally annealed.

Referring still to <FIG> and the bottom of <FIG>, an AS-ALD process that employs additive printing is described. There, the heatable substrate plate <NUM> that supports a build substrate <NUM> is positioned within the printing window <NUM> of the E-jet printing nozzle <NUM> of the electrohydrodynamic jet printing station <NUM>. An inhibition material solution, such PMMA or PVP in H<NUM>O, DMSO, or anisole, is printed onto the working surface <NUM> of the build substrate <NUM> to apply the pattern of the inhibition material <NUM> onto the working surface <NUM>. The pattern of the inhibition material <NUM> defines the ALD growth area <NUM> on the working surface <NUM> where the printed inhibition material pattern has not been applied and is not present. Next, the heatable substrate plate <NUM> is conveyed away from the printing window <NUM> of the E-jet printing nozzle <NUM> and to the SALD station <NUM> by operation of the conveyor <NUM>. The substrate plate <NUM> is positioned within the deposition window <NUM> of the zoned ALD precursor gas distributor <NUM> and heated as needed to support the reaction between the first and second ALD precursor gases. Once in position, an ALD material film <NUM> is deposited layer-by-layer on the growth area by oscillating the build substrate <NUM> relative to the depositor head <NUM> and transverse to the first and second ALD precursor gas zones. After the ALD material film <NUM> has been deposited, the pattern of the inhibition material <NUM> may be exposed to solvent vapors or plasma to remove some or all of the inhibition material pattern <NUM>, if desired, and the substrate plate <NUM> may be conveyed away from the deposition window <NUM> of the zoned ALD precursor gas distributor <NUM> and brought to the cooling station <NUM> where the substrate plate <NUM> and the build substrate <NUM> are cooled. In other scenarios, rather than removing some or all of the inhibition material pattern <NUM>, some or all of the inhibition material pattern <NUM> may be cured with ultraviolet light or be thermally annealed.

It is to be understood that the foregoing description is of one or more preferred example embodiments of the invention. The invention is not limited to the particular embodiment(s) disclosed herein, but rather is defined solely by the claims below. Furthermore, the statements contained in the foregoing description relate to particular embodiments and are not to be construed as limitations on the scope of the invention or on the definition of terms used in the claims, except where a term or phrase is expressly defined above. Various other embodiments and various changes and modifications to the disclosed embodiment(s) will become apparent to those skilled in the art. All such other embodiments, changes, and modifications are intended to come within the scope of the appended claims.

Claim 1:
An integrated electrohydrodynamic jet printing and spatial atomic layer deposition system for conducting nanofabrication, the system comprising:
an electrohydrodynamic jet printing station (<NUM>) that includes an E-jet printing nozzle;
a spatial atomic layer deposition station (<NUM>) that includes a zoned ALD precursor gas distributor (<NUM>) that discharges linear zone-separated first and second ALD precursor gases;
a heatable substrate plate (<NUM>) supported on a motion actuator (<NUM>) controllable to move the substrate plate in three dimensions; and
a conveyor (<NUM>) on which the motion actuator is supported, the conveyor being operative to move the motion actuator between the electrohydrodynamic jet printing station and the spatial atomic layer deposition station so that the substrate plate is conveyable between a printing window (<NUM>) of the E-jet printing nozzle and a deposition window (<NUM>) of the zoned ALD precursor gas distributor, respectively.