Method and system for depositing nano objects onto a receiving surface, and an anchoring 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 system for depositing nano-objects onto a receiving surface. The invention is further directed to a fixation system incorporating such a deposition system. The field of the invention is more particularly the field of quantum components and systems. [Background technology]

[0002] Depositing nanotubes on a surface is currently a real technical challenge due to the very small dimensions of these nanotubes, and depositing them on two electrodes separated by a trench is even more difficult.

[0003] The paper "One-step Direct Transfer of Pristine Signe-Walled Carbon Nanotubes for Functional Nanoelectronics," by Chung Chiang Wu et al., Nanoletters 2010, [1], describes a one-step direct transfer technique for fabricating functional nanoelectronic devices using pristine single-walled carbon nanotubes (SWNTs). Suspended SWNTs grown by chemical vapor deposition (CVD) are aligned and transferred directly onto pre-fabricated 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], describes a fabrication method called "fork stamping" optimized for the dry transfer of individual virgin carbon nanotubes (CNTs) onto ferromagnetic contact electrodes fabricated by standard lithography.

[0005] The paper "Transfer of carbon nanotubes onto microactuators for hysteresis-free transistors at low thermal budget," by 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], describes a dry transfer method for single-walled carbon nanotubes that enables ultra-high-purity, hysteresis-free suspended nanotube field-effect transistors onto microactuation electrodes without subjecting the device chip to high nanotube growth temperatures. Nanotubes are grown on a separate matrix between the arms of a fork-shaped structure and then transferred to a receiving electrode on the device matrix. The device matrix is ​​kept at room temperature, so in principle it could contain temperature-sensitive readout circuitry. Liquid-free transfer at room temperature is performed under optical microscopy, and placement is detected by monitoring the current through the device electrodes.

[0006] Document WO 2020079228 A1 (Delbecq et al.) discloses a method and device for depositing nano objects, which method and device include the steps of approaching a support in an enclosure towards a carrier substrate and transferring the objects from the support to a deposition zone on the carrier substrate in the enclosure, the transferring step being preferably performed while the interior of the enclosure is under vacuum at a pressure of less than 10 bar.

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

[0008] Current methods for assembling qubit components use nanotube clamping techniques, as shown in Figure 6, where it is difficult to control the angle of approach of tip 21, which is provided with nanotube-carrying electrodes 23, to the plane of the receiving tip. It is also virtually impossible to precisely position the nanotube and determine when it has stopped moving along its vertical axis.

[0009] Furthermore, the receiving surface typically has large trenches that can degrade the quality factor of the resonator. Furthermore, the clamping technique is not scalable beyond a few qubits. Furthermore, navigation within the clamping tool is particularly difficult.

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

[0011] Hierold et al. (2012) proposed the idea of ​​building a tip on a cantilever so that the movement of the carbon nanotube is simply the movement between the two cantilevers, which was not possible as it would require substantial changes to the tip design.

[0012] One objective of the present invention is to propose a new technique for coherently transferring nano-objects onto electronic chips / circuits, with as few defects as possible on the resulting chip, as quickly as possible, and as scalably as possible. Summary of the Invention

[0013] Thus, according to a first aspect, the object of the present invention is achieved by a method for depositing nano objects, the nano objects being initially placed on a cantilever tip having a comb structure, characterized in that the method comprises the steps of picking up the nano objects, the picking up step being implemented by a cantilever device or moving fork having two spaced apart arms each provided with one tine, the two tines facing each other and arranged to pick up, hold and release the nano objects, transferring the picked up nano objects to a receiving surface and depositing the nano objects on the receiving surface.

[0014] According to a second aspect, the object of the present invention is achieved by a method for depositing nano objects onto a receiving surface, comprising a first step of picking up the nano objects arranged on a carrier surface, a step of moving the picked-up nano objects to a receiving surface, and a step of depositing the nano objects on the receiving surface, characterized in that the method uses a cantilever movement device comprising two spaced apart arms arranged to pick up, hold and release the nano objects.

[0015] Other advantageous, non-limiting features of the present invention may be combined with the first or second aspect, either alone or in any technically feasible combination.

[0016] In particular, a deposition method is provided for depositing a nano object or at least one nano object, in particular at least one carbon nanotube, on a receiving surface, which comprises a first step of picking up the nano object or at least one nano object or at least one carbon nanotube located on a carrier surface, in particular a cantilever tip or a cantilever semiconductor tip.

[0017] According to one embodiment, at least one nano object is first arranged on a cantilever electrode, in particular on a cantilever tip or a cantilever electrode of a cantilever semiconductor tip.

[0018] Preferably, the cantilever moving device or moving fork comprises two spaced apart arms each provided with one tine, the two tines facing each other and arranged to pick up, hold and release nano objects or carbon nanotubes.

[0019] When the method according to the invention is carried out for the deposition of at least one nano object or at least one carbon nanotube, the support surface may comprise a cantilever semiconductor tip.

[0020] When the method according to the invention is carried out for the immobilization of at least one nano object or at least one carbon nanotube, the support surface may comprise a cantilever semiconductor tip.

[0021] The deposition method according to the invention can be advantageously carried out to deposit at least one nanotube, preferably at least one carbon nanotube, on the electrodes separating the trenches.

[0022] Preferably, during the step of depositing at least one nano object or nanotube or several nanotubes, the arm of the cantilever movement device penetrates two trenches surrounding the electrodes.

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

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

[0025] Preferably, a step of detecting when the cantilever movement device comes into contact with the receiving surface is provided, which step of detecting implements an atomic force probe carrying the cantilever movement device and having a tip attached to a tuning fork or mechanical resonator that is frequency controlled around a predetermined resonant frequency.

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

[0027] According to one example, the method is carried out for depositing at least one nanotube, in particular at least one carbon nanotube, on a microelectronic circuit.

[0028] Preferably, the step of transferring the at least one nanotube, in particular the at least one carbon nanotube, is configured to deposit it on the electrode.

[0029] According to any embodiment, the method may be implemented in the production 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 is proposed, which implements the deposition method according to the present invention, comprising means for picking up the nano object located on a carrier surface, preferably a cantilever tip, means for transferring the picked-up nano object to the receiving surface, and means for depositing the nano object on the receiving surface, which comprises as pick-up, transfer and depositing means at least one cantilever transfer device or at least one transfer fork with two spaced arms arranged to pick up, hold and release the nano object.

[0031] In particular, a deposition system for depositing nano objects onto a receiving surface is proposed, which performs the deposition method according to the invention, and which comprises means for picking up the nano objects arranged on the support surface.

[0032] Preferably, at least one cantilever moving device or at least one moving fork comprises two spaced apart arms each provided with one tine, the tines facing each other and arranged to pick up, hold and release nano objects.

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

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

[0035] The 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, in particular carbon nanotubes, on a plurality of electrodes of a quantum dot electronic circuit.

[0039] In a particular embodiment of the present invention, a system for fixing nanotubes, in particular carbon nanotubes, on a plurality of electrodes is proposed, comprising a deposition system according to the present invention, a fixing device and a device for receiving an electronic circuit of quantum dots.

[0040] Preferably, the system further comprises means for detecting when the cantilever movement device is in contact or at risk of contact with the receiving surface, the detection means comprising an atomic force probe carrying the cantilever movement device and having a tip attached to a tuning fork that is frequency regulated around a predetermined resonant frequency.

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

[0042] According to one embodiment, the system is located in a stationary chamber within the system for producing qubit components.

[0043] According to one embodiment, there is provided a system for immobilizing carbon nanotubes to produce qubit components, the system comprising an immobilization chamber incorporating a deposition system according to one of the preceding features.

[0044] The invention involves transferring the carbon nanotube onto a single small cantilever intermediate, which allows the trench to be much smaller, saving 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 drawings]

[0046] [Figure 1] FIG. 1 is a perspective view of a prior art stationary chamber. [Figure 2] FIG. 2 is a view of the interior of the stationary chamber of FIG. 1. [Figure 3] 1 shows a receiving substrate and a multi-electrode circuit implemented with a prior art deposition method. [Figure 4] As in the prior art, an example of a cantilever array tip accessing two trenches separated by a set of aligned electrodes is shown. [Figure 5] 1 shows an example of a multi-electrode circuit implemented in a prior art deposition method. [Figure 6] 6 shows an example of a prior art approach made difficult by imperfect angular control of the multi-electrode circuit of FIG. 5 on a prior art receiving substrate. [Figure 7] 1 shows an example of a cantilever movement device for use in a nanotube deposition system according to the present invention. [Figure 8] FIG. 8 is a close-up view of one end of the cantilever movement device of FIG. 7. [Figure 9] 1 shows nanotubes on a multi-electrode circuit. [Figure 10]10 shows top and side views of the approach to the cantilever translation device for the first translation of the nanotube of FIG. 9. [Figure 11] This shows the movement of a nanotube using a cantilever movement device. [Figure 12] 2 shows an approach to a cantilever translation device for nanotube translation. [Figure 13] 13 shows the cantilever translation device of FIG. 12 carrying the nanotube in contact with the electrode for a second translation. [Figure 14] 1 shows the nanotube on the substrate after the second transfer. [Figure 15] This demonstrates the significant reduction in trench size made possible by the deposition method of the present invention. [Figure 16] 1 shows the space saved by reducing the size of the trench. [Figure 17] 1 illustrates an example embodiment of a deposition method according to the present invention. [Figure 18] 1 is a perspective view of an example embodiment of a fastening system according to the present invention; [Figure 19] FIG. 19 is a cross-sectional view of the fixation system shown in FIG. 18. [Figure 20] FIG. 20 is an enlarged view of the interior of the fastening system shown in FIGS. 18 and 19. [Figure 21] 18, 19 and 20 show top views of an AFM device fitted with the fixture system shown in FIGS. 18, 19 and 20, and a close-up of an electronic circuit treated with the deposition method according to the present invention. [Figure 22] FIG. 22 is an enlarged perspective view of the AFM device shown in FIG. 21. [Figure 23] FIG. 23 is a close-up view of the cantilever movement device coupled to the AFM device of FIG. 22. [Figure 24] FIG. 24 is a detailed view of the AFM device shown in FIG. 23. DETAILED DESCRIPTION OF THE INVENTION

[0047] 7 and 8, we will first describe an example of a cantilever movement device 3. This movement device 3 comprises two elongated blades 310, 320 separated by a piece of insulating material. These two blades 310, 320 have bending arms 31, 32 at one end and portions at the other end for attachment to a mechanical fixation device (not shown) located in a fixation chamber.

[0048] The cantilever movement device 3 is designed to pick up a carbon nanotube 4 arranged on a cantilever 41, 42 of a support structure 23 (see Figures 9 and 10).

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

[0050] It should be noted that the transfer and deposition techniques provided by the present invention allow for a significant reduction in the width of the trenches in the receiving structure, as shown in FIGS. 15 and 16. This allows for a switch from a trench width of approximately 3 mm to a trench width of approximately 30 μm. In this way, the receiving chip 5 is positioned on the protrusion 26 between two very narrow trenches. A nanotube 4 can then be deposited on the receiving chip 5, which is positioned between two trenches 41, 42, as shown in FIG. 16, and connected to a circuit 6 located 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 transfer device is used to perform two transfers of the target carbon nanotube. First, the fork is essentially used to "pull" the nanotube suspended between two cantilevers on a cantilever growth tip with a comb structure. After this transfer, the nanotube is attached to the end of the fork and suspended between its two tines. The fork with the nanotube attached is then brought into contact with the tip of a qubit device, and the nanotube is precisely transferred onto the source and drain electrodes suspended above an array of gate electrodes. A more detailed overview of the intermediate fork design and transfer process is provided below.

[0052] The intermediate fork or cantilever transfer device consists of two microfabricated tines attached to a rectangular support base. The fork and its base can be fabricated from an insulating material such as silicon or silicon nitride (the specific material is irrelevant) using conventional lithography and etching techniques. The tips of the tines must be metallized, either by vapor deposition coating or lithography, and electrically connected to the flares of the support base. This connectivity is essential for the second transfer process to the qubit chip and can also facilitate the first transfer from the growth 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 tines must be large enough to allow the outermost qubit device electrode to fit between the tines for the second movement (approximately 10 μm). The tines must also be long enough so that the tips of the fork are easily resolved with an optical microscope when oriented at a small angle (approximately 2 degrees) relative to the normal, as shown in Figure 13. Furthermore, to facilitate easy nanotube movement, the tines must also be significantly longer than the thickness of the growth cantilever and the depth of the trench / pit on the qubit chip. Therefore, tines on the order of 100–500 μm in length are required. Finally, the tines must be thick enough to provide a large enough surface area for the nanotube to attach to its tip during the first movement, and therefore should be approximately 10 μm thick. This thickness further impacts the mechanical strength of the tines, which are designed to withstand numerous nanoassembly cycles.

[0054] The first movement begins by optically aligning the fork tips over the location of a target nanotube suspended between two cantilevers on the growth tip. Once aligned, the forks are then lowered to bring the metallized fork tips into contact with the suspended nanotube.

[0055] 18-24, a specific embodiment of a clamping system according to the present invention will now be described, which provides for detection of contact between a cantilever movement device and a receiving surface and which implements an atomic force microscope architecture.

[0056] Document WO2021009290A1 (Nigues et al.) discloses an atomic force microscope for evaluating sample surfaces, 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, the microscope being configured to allow adjustment of the position of the tip relative to the surface and the support, the sample holder having at least one second zone different from the first zone and fixed relative to the support, the sample holder being deformable to allow relative displacement of the first zone with respect to the second zone, and the microscope comprising a detector suitable for detecting the displacement of the first zone with respect to the second zone.

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

[0058] Atomic Force Microscope (AFM) technology can be used to detect when the tip of the cantilever approaches the trench. The problem has been that this requires substantial modifications to the cantilever design. In AFM technology, the oscillator is very small and difficult to incorporate into any design.

[0059] The fixturing system, with reference to Figures 23 and 24, comprises a fork-shaped translation probe 10 coupled to a tuning fork (or mechanical resonator) and nanopositioner assembly 200. To utilize AFM detection during the translation 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 inspired by the MicroMegascope described in the aforementioned publication [4], which is 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 attached to the top of the tuning fork 200. A microelectromechanical systems (MEMS) accelerometer chip 122 attached to the side of the tuning fork 200 near the tip 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 transforms the interaction between its tip and the surface / nanotube during the movement process, disturbing the vibration of the tuning fork 200.

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

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

Claims

1. A method for depositing at least one nano object (4) on a receiving surface (20), the nano object being first placed on a cantilever tip having a comb structure, - picking up the nano objects (4), which comprises a cantilever device or moving fork (3) with two spaced apart arms (31, 32) each provided with one tine, said two tines facing each other and arranged to pick up, hold and release the nano objects (4); - transferring the picked-up nano objects (4) to the receiving surface (20); - depositing said nano objects (4) on said receiving surface (20).

2. 2. The deposition method according to claim 1, used to deposit at least one nano object (4) on an electrode separating trenches.

3. 3. The deposition method of claim 2, wherein during the step of depositing the at least one nano object, the arm of the cantilever movement device penetrates into two trenches surrounding an electrode.

4. 4. The deposition method of claim 3, wherein the trench between the electrodes is less than 100 [mu]m wide.

5. 5. The deposition method according to claim 1, further comprising a step of detecting when the cantilever movement device (30) comes into contact with the receiving surface (20), characterized in that the detection step is implemented by implementing an atomic force probe (1) carrying the cantilever movement device (30) and comprising a tip (10) attached to a tuning fork or mechanical resonator (11, 12) that is frequency-controlled around a predetermined resonant frequency.

6. 6. The deposition method of claim 5, wherein the detection step includes providing distance information between the tip (10) carrying the cantilever movement device (30) and the receiving surface (20), the distance information being processed to control the movement step.

7. 7. The deposition method according to claim 6, used for depositing at least one carbon nanotube (4) on a microelectronic circuit (20).

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

9. Deposition method according to any one of claims 1 to 8, characterized in that it is implemented in the production of qubit components.

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

11. 11. The deposition system (10) of claim 10, wherein each blade (310, 320) comprises an elongated portion, one cantilever end having an arm substantially perpendicular to said elongated portion.

12. The deposition system of claim 11 , wherein the arm has a conductive coating.

13. The deposition system of any one of claims 10 to 12, implemented for depositing at least one carbon nanotube on electrodes separated by trenches.

14. 14. The deposition system of claim 13, wherein the trench between electrodes is less than 100 μm wide.

15. The deposition system according to any one of claims 10 to 14, characterized in that it is implemented in a system for fixing nanotubes onto a plurality of electrodes of a quantum dot electronic circuit.

16. 16. A deposition system according to any one of claims 10 to 15, further comprising means (1) for detecting when the cantilever movement device (3, 30) comes into contact with the receiving surface (20) or when there is a risk of contact, said detection means comprising an atomic force probe (1) carrying the cantilever movement device (3, 30) and having a tip (10) attached to a tuning fork (11, 12) that is frequency regulated around a predetermined resonant frequency.

17. 17. The deposition system (2) according to claim 16, characterized in that the detection means further comprises means for outputting deviation information between the tip (10) carrying the cantilever movement device (3, 30) and the receiving surface (20), and means for controlling the movement means based on the deviation information.

18. 20. The deposition system of claim 17, wherein the deposition system is disposed in a stationary chamber in a system for producing qubit components.

19. A system for immobilizing carbon nanotubes to produce qubit components, the system comprising an immobilization chamber incorporating a deposition system according to any one of claims 16 to 18.

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