Method and system for depositing nanomaterials on a receiving surface, and immobilization system incorporating such a deposition system

Abstract

The present invention relates to a method for depositing nano objects (4) on a receiving surface (20), comprising a first step of picking up the nano objects (4) arranged on a carrier surface, a step of transferring the picked-up nano objects (4) to the receiving surface (20), and a step of depositing the nano objects (4) on the receiving surface (20), characterized in that the method uses a cantilever movement device (4) comprising two spaced apart arms (31, 32) arranged to pick up, hold and release the nano objects.

Description

Technical Field

[0001] The present invention relates to a method and a system for depositing nano-objects on a receiving surface. The present invention further aims at a fixing system incorporating such a deposition system. The field of the present invention is, more particularly, the field of quantum components and systems.

Background Art

[0002] Depositing nanotubes on a surface is currently a realistic technical challenge because of the very small dimensions of these nanotubes. Depositing nanotubes on two electrodes separated by trenches is even more difficult.

[0003] The paper "One-step Direct Transfer of Pristine Signe-Walled Carbon Nanotubes for Functional Nanoelectronics", Chung Chiang Wu et al, Nanoletters 2010, [1] discloses a one-step direct transfer technique for manufacturing functional nanoelectronic devices using pristine single-walled carbon nanotubes (SWNTs). The suspended SWNTs grown by chemical vapor deposition (CVD) method are aligned and directly transferred onto pre-constructed device electrodes at room temperature.

[0004] The paper "Fork stamping of pristine carbon nanotubes onto ferromagnetic contacts for spin-valve devices", J. Gramich et al., Phys. Status, 2015, [2] discloses a manufacturing method called "fork stamping" optimized for the dry transfer of individual virgin carbon nanotubes (CNTs) onto ferromagnetic contact electrodes manufactured by standard lithography.

[0005] The paper “Transfer of carbon nanotubes onto microactuators for hysteresis-free transistors at low thermal budget,” M. Muoth and C. Hierold, 2012 IEEE 25th International Conference on Micro Electro Mechanical Systems (MEMS), 2012, pp.1352-1355, doi:10.1109 / MEMSYS.2012.6170417,[3] discloses a dry transfer method for single-walled carbon nanotubes that enables ultra-high purity, hysteresis-free suspended nanotube field-effect transistors on microactuators without exposing the device chip to high nanotube growth temperatures. The nanotubes are grown on a separate matrix between the arms of a fork-like structure and then transferred to a receiving electrode on the device matrix. Since the device matrix is ​​kept at room temperature, it is theoretically possible to include temperature-sensitive readout circuits. The liquid-free transfer at room temperature is performed under optical microscopy observation, and the placement is detected by monitoring the current through the device electrodes.

[0006] International Publication No. 2020079228A1 (Delbecq et al.) discloses a method and device for depositing nanomaterials, the method and device comprising the steps of bringing a support toward a carrier substrate within an enclosure, and moving the material from the support to a deposition zone on the carrier substrate within the enclosure. The moving step is preferably performed while the inside of the enclosure is under vacuum at a pressure of less than 10⁻⁶ bar.

[0007] As an example of prior art, a fixed chamber 2 maintained under a high ultra-high vacuum (UHV) is an integral part of the nanofabrication apparatus 1, as shown in Figure 1. Referring to Figures 2 to 5, the fixed chamber includes a chip 20 equipped with electrodes 23, on which carbon nanotubes initially present on cantilever electrodes 23 extending a circuit or electronic chip 21 are deposited.

[0008] Current methods for assembling qubit components use nanotube immobilization techniques, and as shown in Figure 6, it is difficult to control the angle of approach of the tip 21, on which the nanotube-supported electrode 23 is located, to the plane of the receiving tip. It is also virtually impossible to precisely position the nanotubes and determine when they stop moving along the vertical axis.

[0009] Furthermore, the receptacle surface generally has large trenches, which can degrade the quality coefficient of the resonator. Additionally, the fixing techniques are not scalable beyond a few qubits. Moreover, navigation within the fixing tool is particularly difficult.

[0010] The first solution was to completely eliminate the trenches by working with a tip that has electrodes on the arms instead of on the trenches. However, the problem with this design is that it changes the entire nanofabrication process. The goal is to solve the problem without changing the tip design.

[0011] Hierold et al (2012) proposed the idea of ​​constructing the chip on a cantilever so that the movement of carbon nanotubes is simply movement between two cantilevers. This proved impossible because it would require substantial changes to the chip design.

[0012] One objective of the present invention is to propose a novel technique for coherently moving nanomaterials onto electronic chips / circuits, minimizing defects on the resulting chip, moving them as quickly and scalably as possible. [Overview of the project]

[0013] Accordingly, according to a first aspect of the present invention, an object to the present invention is achieved by a method for depositing nanomaterials, wherein the nanomaterials are first placed on a cantilever tip having a comb structure, and the nanomaterials are picked up, the pick-up step comprising: implementing a cantilever device or moving fork having two spaced-apart arms each provided with one tooth, the two teeth facing each other and arranged to pick up, hold, and release the nanomaterials; moving the picked-up nanomaterials to a receiving surface; and depositing the nanomaterials on the receiving surface.

[0014] According to a second aspect of the present invention, an object to the present invention is achieved by a method for depositing nanomaterials on a receiving surface, comprising the steps of: a first step of picking up the nanomaterials placed on a support surface; a step of moving the picked-up nanomaterials to a receiving surface; and a step of depositing the nanomaterials on the receiving surface, wherein the method is characterized by using a cantilever moving device including two spaced-apart arms arranged to pick up, hold, and release the nanomaterials.

[0015] Another advantageous and non-limiting feature of the present invention is that it can be used alone or in any technically feasible combination with the first or second embodiment.

[0016] In particular, a deposition method is provided for depositing a nanoobject or at least one nanoobject, in particular at least one carbon nanotube, onto a receiving surface, the deposition method comprising a first step of picking up the nanoobject or at least one nanoobject or at least one carbon nanotube disposed on a supporting surface, in particular on a cantilever chip or a cantilever semiconductor chip.

[0017] According to one embodiment, at least one nanomaterial is initially placed on a cantilever electrode, particularly a cantilever tip or a cantilever semiconductor tip.

[0018] Preferably, the cantilever moving device or moving fork comprises two spaced arms, each having one tooth, with the two teeth facing each other and arranged to pick up, hold, and release nanomaterials or carbon nanotubes.

[0019] When the method according to the present invention is carried out for the deposition of at least one nanomaterial or at least one carbon nanotube, the support surface may include a cantilever semiconductor chip.

[0020] When the method according to the present invention is carried out for the immobilization of at least one nanoobject or at least one carbon nanotube, the support surface may include a cantilever semiconductor chip.

[0021] The deposition method according to the present invention can be advantageously carried out to deposit at least one nanotube, preferably at least one carbon nanotube, on an electrode that separates trenches.

[0022] Preferably, during the step of depositing at least one nanomaterial or nanotube or several nanotubes, the arm of the cantilever moving device penetrates two trenches surrounding the electrode.

[0023] These electrodes can be advantageously arranged to generate qubit components.

[0024] Using the deposition methods described herein, it is possible to deposit nanomaterials or nanotubes on circuits having inter-electrode trenches less than 100 μm wide, typically 30 μm wide.

[0025] Preferably, a step of detecting when the cantilever moving device contacts the receiving surface is provided, and this detecting step implements an atomic force probe carried by the cantilever moving device and having a tip attached to a tuning fork or a mechanical resonator that is frequency-controlled near a predetermined resonance frequency.

[0026] Preferably, the detecting step includes a step of providing distance information between the tip carrying the cantilever moving device and the receiving surface, and the distance information is processed to control the moving step.

[0027] According to one example, the method is implemented to deposit at least one nanotube, particularly at least one carbon nanotube, on a microelectronic circuit.

[0028] Preferably, the moving step of at least one nanotube, particularly at least one carbon nanotube, is configured to deposit it on an electrode.

[0029] According to any embodiment, the method can be implemented in the generation of qubit components.

[0030] According to another aspect of the present invention, a system for depositing at least one nano-object on a receiving surface, which implements the deposition method according to the present invention, includes a supporting surface, preferably means for picking up this nano-object located on a cantilever chip, means for moving the picked-up nano-object to the receiving surface, and means for depositing the nano-object on the receiving surface. It includes at least one cantilever moving device, or at least one moving fork having two spaced arms arranged to pick up, hold, and release the nano-object, as the picking-up, moving, and depositing means.

[0031] In particular, a deposition system for depositing nanomaterials onto a receiving surface, which implements the deposition method according to the present invention, is proposed, comprising means for picking up the nanomaterials placed on the support surface.

[0032] Preferably, at least one cantilevered moving device or at least one moving fork comprises two spaced arms, each having one tooth, which are opposed to each other and arranged to pick up, hold, and release nanoobjects.

[0033] Preferably, the cantilever moving device may take the form of two substantially parallel blades separated by an insulating piece.

[0034] Each blade may include, for example, an elongated portion with a cantilevered end having an arm substantially perpendicular to the elongated portion.

[0035] These arms may include a conductive coating.

[0036] The system according to the present invention can be advantageously implemented to deposit at least one carbon nanotube on electrodes separated by trenches.

[0037] Preferably, the trench between the electrodes is less than 100 μm wide.

[0038] Preferably, the system is implemented in a system for immobilizing nanotubes, particularly carbon nanotubes, on multiple electrodes of a quantum dot electronic circuit.

[0039] In a particular embodiment of the present invention, a system is proposed for immobilizing nanotubes, particularly carbon nanotubes, on multiple electrodes, comprising a deposition system according to the present invention, an immobilization device, and a device for receiving the electronic circuits of quantum dots.

[0040] Preferably, the system further comprises means for detecting when the cantilever moving device is in contact with or at risk of contact with a receiving surface, the detection means comprising an interatomic force probe having a tip attached to a tuning fork that supports the cantilever moving device and is frequency-controlled near a predetermined resonant frequency.

[0041] Preferably, the detection means further comprises means for outputting deviation information between a tip supporting a cantilever moving device and a receiving surface, and further comprises means for controlling the moving means based on the deviation information.

[0042] According to one embodiment, the system is located within a fixed chamber for generating qubit components.

[0043] According to one embodiment, a system is provided for generating qubit components by immobilizing carbon nanotubes, the system comprising an immobilization chamber that incorporates a deposition system according to one of the above-mentioned features.

[0044] This invention involves moving carbon nanotubes onto a single, small cantilever intermediate. This allows for much smaller trenches and saves space on the chip for future upgradeable designs.

[0045] References [1] “One-step Direct Transfer of Pristine Signe-Walled Carbon Nanotubes for Functional Nanoelectronics”, Chung Chiang Wu et al, Nanoletters 2010 [2] “Fork stamping of pristine carbon nanotubes onto ferromagnetic contacts for spin-valve devices”, J. Gramich et al., Phys.Status, 2015 [3] “Transfer of carbon nanotubes onto microactuators for hysteresis-free transistors at low thermal budget” M. Muoth and C. Hierold, 2012 IEEE 25th International Conference on Micro Electro Mechanical Systems (MEMS), 2012, pp. 1352-1355, doi:10.1109 / MEMSYS.2012.6170417 [4]MicroMegascope(Canale et al.),arXiv:1805.05231v1[physics.ins-det]14 May 2018 [Brief explanation of the drawing]

[0046] [Figure 1] This is a perspective view of a conventional fixed chamber. [Figure 2] Figure 1 is a diagram showing the inside of the fixed chamber. [Figure 3] This shows a receiving substrate and a multi-electrode circuit implemented using a conventional deposition method. [Figure 4] An example of a cantilever array chip approaching two trenches separated by a set of aligned electrodes, as in conventional technology, is shown. [Figure 5] An example of a multi-electrode circuit implemented using conventional deposition methods is shown. [Figure 6] This shows an example of a conventional approach that has become difficult due to the imperfect angle control of the multi-electrode circuit shown in Figure 5 on the conventional receiving substrate. [Figure 7] An example of a cantilever movement device used in the nanotube deposition system according to the present invention is shown. [Figure 8] Figure 7 is a magnified view of one end of the cantilever moving device. [Figure 9] This shows nanotubes on a multi-electrode circuit. [Figure 10]Figure 9 shows a top and side view of the approach to the cantilever transfer device for the first movement of the nanotube. [Figure 11] This shows the movement of nanotubes using a cantilever-type moving device. [Figure 12] This paper presents an approach to a cantilever-type transport device for the second type of nanotube transport. [Figure 13] Figure 12 shows a cantilever movement device that supports nanotubes in contact with electrodes for a second movement. [Figure 14] The nanotubes on the substrate after the second migration are shown. [Figure 15] This demonstrates the significant reduction in trench size made possible by the deposition method of the present invention. [Figure 16] This shows the space saved by reducing the size of the trench. [Figure 17] An example embodiment of the deposition method according to the present invention is shown. [Figure 18] This is a perspective view of an example embodiment of the fixed system according to the present invention. [Figure 19] Figure 18 is a cross-sectional view of the fixed system. [Figure 20] Figures 18 and 19 show enlarged views of the inside of the fixed system. [Figure 21] Figures 18, 19, and 20 show a top view of an AFM device adapted to the fixed system, and an enlarged view of an electronic circuit processed by the deposition method according to the present invention. [Figure 22] Figure 21 is an enlarged perspective view of the AFM device shown. [Figure 23] Figure 22 is an enlarged view of the cantilever movement device connected to the AFM device. [Figure 24] Figure 23 is a detailed view of the AFM device. [Modes for carrying out the invention]

[0047] Referring to Figures 7 and 8, an example of a cantilever moving device 3 will first be described. This moving device 3 comprises two elongated blades 310, 320 separated by an insulating material piece. These two blades 310, 320 have a bendable arm 31, 32 at one end and a portion at the other end for attachment to a mechanical fixing device (not shown) located in a fixing chamber.

[0048] The cantilever transfer device 3 is designed to pick up carbon nanotubes 4 positioned on the cantilevers 41 and 42 of the support structure 23 (see Figures 9 and 10).

[0049] When the arms 31 and 32 of the cantilever moving device 3 come into contact with the nanotube 4, the nanotube 4 is held in place by van der Waas forces. The moving device 3 can then transport the nanotube to the receiving structure (see Figures 11-12). The cantilever moving device 3, carrying the nanotube 4, approaches the receiving structure that houses the electronic chip 5 positioned between two trenches, and then deposits the nanotube 4 onto the chip 5, as shown in Figures 13, 14, and 17.

[0050] It should be noted that the transport and deposition techniques provided by the present invention allow for a significant reduction in the width of the trenches of the receiving structure, as shown in Figures 15 and 16. This enables switching from a trench width of approximately 3 mm to approximately 30 μm. In this way, the receiving tip 5 is positioned on a projection 26 between two very narrow trenches. The nanotubes 4 are then deposited on the receiving tip 5 positioned between the two trenches 41, 42, as shown in Figure 16, and can be connected to a circuit 6 positioned on the receiving structure 20.

[0051] In the nanotube deposition method according to the present invention, an intermediate fork in the form of a cantilever moving device is used to perform two moves of the target carbon nanotube. Firstly, the fork is essentially used to "draw out" a nanotube suspended between two cantilevers on a cantilever growth chip having a comb structure. After this move, the nanotube is attached to the end of the fork and suspended between its two teeth. The fork with the attached nanotube is then brought into contact with a qubit device chip to precisely move this nanotube onto source and drain electrodes suspended above an array of gate electrodes. A more detailed overview of the intermediate fork design and the moving process is given below.

[0052] The intermediate fork or cantilever moving device consists of two micro-machined teeth mounted on a rectangular support base. The fork and its base can be fabricated from insulating materials such as silicon or silicon nitride (the specific material is irrelevant) using conventional lithography and etching techniques. The tips of the teeth must be metallized by either vapor deposition coating or lithography and electrically connected to the flares of the support base. This connectivity is essential for the second moving process to the qubit chip and also facilitates the first moving from the growing chip.

[0053] The width of the fork is limited by the requirement to fit between the cantilever pair on the growth chip for the first movement (approximately 30 μm). The gap between the fork teeth must be large enough for the outermost qubit device electrode to fit between the teeth for the second movement (approximately 10 μm). The teeth must also be long enough so that the tip of the fork is easily resolved with an optical microscope when oriented at a small angle (approximately 2 degrees) with respect to the normal, as shown in Figure 13. Furthermore, to facilitate the easy movement of the nanotube, the teeth must also be significantly longer than the thickness of the growth cantilever and the depth of the trench / pit on the qubit chip. Thus, teeth of approximately 100-500 μm in length are required. Finally, the teeth must be thick enough to provide a sufficiently large surface area for the nanotube to attach to their tip during the first movement, and therefore should be approximately 10 μm thick. This thickness further affects the mechanical strength of the teeth, which are designed to withstand numerous nano-assembly cycles.

[0054] The first movement is initiated by optically aligning the tip of the fork over the position of the target nanotube suspended between two cantilevers on the growth chip. Once aligned, the fork is then lowered to bring the metallized fork tip into contact with the suspended nanotube.

[0055] Next, with reference to Figures 18 to 24, a specific embodiment of the immobilization system according to the present invention that provides detection of contact between a cantilever moving device and a receiving surface and implements an atomic force microscope architecture will be described.

[0056] The document WO2021009290A1 (Nigues et al.) discloses an atomic force microscope for evaluating a sample surface, comprising a sample holder having a first zone adapted to receive a fixedly mounted sample, and a probe having a tip adapted to be positioned facing the sample surface, wherein the microscope is configured to allow adjustment of the position of the tip relative to the surface and support, the sample holder having at least one second zone fixed to the support, distinct from the first zone, the sample holder is deformable to allow relative displacement of the first zone with respect to the second zone, and the microscope comprises a detector suitable for detecting the displacement of the first zone with respect to the second zone.

[0057] The MicroMegascope literature (Canale et al.), 2018[4] discloses an atomic force imaging device having a centimeter-sized oscillator. This device enables the generation of topographic images with nanometer resolution using a centimeter-sized tuning fork or mechanical resonator equipped with an accelerometer for measuring resonator vibrations.

[0058] Atomic force microscopy (AFM) techniques can be used to detect when the cantilever tip approaches the trench. The problem was that this required substantial changes to the cantilever design. In AFM techniques, the oscillator is very small and difficult to incorporate into any design.

[0059] The stationary system, referring to Figures 23 and 24, includes a tuning fork (or mechanical resonator) and a fork-shaped moving probe 10 coupled to a nanopositioner assembly 200. To utilize AFM detection during the moving process, the fork probe 10, in the form of a microchip mounted on a printed circuit board 100, is attached to the end 121 of a tuning fork or mechanical resonator, which is inspired by the MicroMegascope described in the aforementioned reference [4] and mounted on a stack 130 of x / y / z nanopositioning motors.

[0060] The vibration of the tuning fork 200 is driven by a piezoelectric actuator 120 mounted on the top of the tuning fork 200. A micro electro-mechanical systems (MEMS) accelerometer chip 122 mounted on the side near the tip of the tuning fork 200 is used to detect the movement of the tuning fork 200. A fork-shaped probe 10 attached to the end of the tuning fork 200 converts the interaction between its tip and the surface / nanotube during the movement process, hindering the vibration of the tuning fork 200.

[0061] These changes in the vibration of the tuning fork 200 are measured by an accelerometer and electrically coded. A phase-locked loop (PLL) controller (external electronic equipment, not shown) is used to retract and extend the nano-positioning motor along the z-axis according to the signal from the accelerometer 122. The phase-locked loop PLL may then be configured to trigger an alarm when the tip of the fork-moving probe 10 comes into contact with the nanotube or surface 20, thereby avoiding collisions by maintaining a safe separation between the tip of the probe 10 and the surface of the quantum circuit chip.

[0062] Naturally, the present invention is not limited to the embodiments described above, and numerous other configurations can be envisioned without departing from the scope of the present invention.

Claims

1. A method for depositing at least one nano-object (4) on a receiving surface (20), wherein the nano-object is initially placed on a cantilever tip having a comb structure. - A step of picking up the nano-object (4), wherein this pickup step uses a cantilever moving device (3) having two spaced-apart arms (31, 32) each provided with one tooth, the two teeth facing each other and arranged to pick up, hold, and release the nano-object (4), - A step of moving the picked-up nano-object (4) to the receiving surface (20), - The process includes the step of depositing the nano-object (4) onto the receiving surface (20), A method further comprising the step of detecting when the cantilever moving device (3) comes into contact with the receiving surface (20), wherein the detection step is characterized by mounting an interatomic force probe (1) that supports the cantilever moving device (3) and has a tip (10) attached to a tuning fork or mechanical resonator (11, 12) that is frequency-controlled near a predetermined resonant frequency.

2. The deposition method according to claim 1, used for depositing at least one nano-object (4) on an electrode that separates trenches.

3. The deposition method according to claim 2, characterized in that during the step of depositing at least one nanomaterial, the arm of the cantilever moving device penetrates two trenches surrounding the electrode.

4. The deposition method according to claim 3, characterized in that the trench between the electrodes has a width of less than 100 μm.

5. The deposition method according to claim 1, wherein the detection step includes providing distance information between the tip (10) supporting the cantilever moving device (3) and the receiving surface (20), and the distance information is processed to control the moving step.

6. The deposition method according to claim 5, wherein the nanomaterial (4) is a carbon nanotube (4), and is used to deposit at least one carbon nanotube (4) on the receiving surface (20) of a microelectronic circuit.

7. The deposition method according to claim 6, characterized in that the step of moving the at least one carbon nanotube (4) is configured to deposit it on an electrode.

8. The deposition method according to claim 1, characterized in that it is carried out in the generation of qubit components.

9. A system (10) for depositing at least one nanoobject (4) on a receiving surface (20), comprising a cantilever moving device (3) for picking up the nanoobject located on a support surface (21), moving the thus picked up nanoobject onto the receiving surface (20), and depositing the nanoobject (4) on the receiving surface (20), wherein the pick-up, moving and deposit means comprises two spaced arms (31, 32) each provided with one tooth, the teeth facing each other and arranged to pick up, hold and release the nanoobject (4), A system for carrying out the deposition method according to claim 1, characterized in that the cantilever moving device (3) is in the form of two substantially parallel blades (310, 320) separated by an insulating piece (33).

10. The deposition system (10) according to claim 9, characterized in that each blade (310, 320) has an elongated portion, and one cantilever end has an arm substantially perpendicular to the elongated portion.

11. The deposition system according to claim 10, characterized in that the arm has a conductive coating.

12. The deposition system according to claim 9, which is carried out to deposit at least one carbon nanotube on electrodes separated by trenches.

13. The deposition system according to claim 12, characterized in that the trench between the electrodes has a width of less than 100 μm.

14. The deposition system according to claim 9, characterized in that it is implemented in a system for fixing nanotubes on multiple electrodes of a quantum dot electronic circuit.

15. The deposition system according to claim 9, further comprising means (1) for detecting when the cantilever moving device (3) comes into contact with or is at risk of coming into contact with the receiving surface (20), wherein these detection means comprises an interatomic force probe (1) having a tip (10) attached to a tuning fork (11, 12) that supports the cantilever moving device (3) and is frequency-controlled near a predetermined resonant frequency.

16. The deposition system (2) according to claim 15, wherein the detection means further comprises means for outputting deviation information between the tip (10) that supports the cantilever moving device (3) and the receiving surface (20), and further comprises means for controlling the pickup, moving and deposition means based on the deviation information.

17. The deposition system according to claim 16, characterized in that it is located within a fixed chamber in a system for generating qubit components.

18. A system for immobilizing carbon nanotubes to generate qubit components, comprising an immobilization chamber incorporating the deposition system described in claim 15.

Images