Method and system for depositing nano-objects on receiving surface and fastening system incorporating such deposition system

Abstract

The invention relates to a method for depositing a nano-object (4) on a receiving surface (20), comprising a first step of picking up such a nano-object (4) on a bearing surface, a step of transferring the picked-up nano-object (4) onto the receiving surface (20), and a step of depositing a nano-object (4) on the receiving surface (20), the method is characterized in that it uses a cantilevered transfer device (4) comprising two spaced apart arms (31, 32) arranged to pick up, hold and release nanoobjects.

Description

Technical Field

[0001] The invention relates to a method and a system for depositing nano-objects on a receiving surface. The invention also aims at a fastening system incorporating such a deposition system. The field of the invention is more particularly that of quantum components and systems. Background Art

[0002] Depositing nanotubes on a surface is currently a practical technical challenge due to the extremely small size of these nanotubes. It is even more difficult when depositing nanotubes on two electrodes separated by a trench.

[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 fabricating functional nanoelectronic devices using pristine single-walled carbon nanotubes (SWNTs). Suspended SWNTs grown by chemical vapor deposition (CVD) are aligned and directly transferred to pre-configured 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 fabrication method called “fork stamping” that is optimized for dry transfer of single pristine carbon nanotubes (CNTs) onto ferromagnetic contact electrodes fabricated by standard photolithography.

[0005] The paper “Transfer of carbon nanotubes onto microactuators for hysteresis-free transistors at low thermal budget” (M. Muoth and C. Hierold, 2012 25th IEEE International Conference on Microelectromechanical Systems (MEMS), pp. 1352-1355, doi:10.1109 / MEMSYS.2012.6170417, [3]) discloses a dry transfer method for single-walled carbon nanotubes that enables ultrapure, hysteresis-free suspended nanotube field-effect transistors to be realized on microactuator electrodes without exposing the device chip to high nanotube growth temperatures. The nanotubes are grown on a separate substrate between the arms of a fork-shaped structure and then transferred to receiving electrodes on the device substrate. The matrix of the device is maintained at room temperature, so in principle it can contain temperature-sensitive readout circuitry. The 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 WO2020079228A1 (Delbecq et al.) discloses a method and apparatus for depositing nano-objects, the method comprising: approaching a support in a housing in the direction of a carrier substrate; then transferring the object from the support to a deposition area on the carrier substrate in the housing. The transfer step is preferably carried out at a pressure of less than 10 -6 bar vacuum.

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

[0008] Current methods for assembling qubit components use nanotube fastening techniques, where it is difficult to control the angle at which a chip 21 provided with nanotube-bearing electrodes 23 approaches the plane of a receiving chip, such as Figure 6 It is also virtually impossible to precisely locate the nanotube and determine when the nanotube stops translating along the vertical axis.

[0009] In addition, the receiving surface is often provided with large grooves, which can be the source of degradation of the resonator quality factor. Moreover, the fastening technique cannot be extended to more than a few qubits. What's more, navigating inside the fastening tool is particularly difficult.

[0010] The first solution is to remove the grooves altogether by using a chip with electrodes on the arms instead of on the grooves. But the problem with this design is that it changes the entire nanofabrication process. The goal is to solve the problem without changing the chip design.

[0011] Hierold et al. proposed in 2012 the idea of ​​building a chip on cantilevers, so that the transfer of carbon nanotubes is simply a transfer between two cantilevers. This is not possible because it would require substantial changes to the chip design.

[0012] It is an object of the present invention to propose a new technique for transferring nano-objects onto electronic chips / circuits in a coherent manner, wherein the new technique allows to have as few defects as possible on the resulting chip, is as fast as possible and is as scalable as possible. Summary of the invention

[0013] According to a first aspect, the object of the invention is therefore achieved by a method for depositing nano-objects, which are initially located on a cantilever chip with a comb-like structure, characterized in that the method comprises: a step of picking up such nano-objects, which picking up step is realized by a cantilever device or a transfer fork, which cantilever device or transfer fork comprises two spaced-apart arms, each arm is provided with tines, which two tines face each other and are arranged to pick up, hold and release the nano-objects; a step of transferring the picked up nano-objects to a receiving surface; and a step of depositing the nano-objects onto the receiving surface.

[0014] According to a second aspect, the object of the invention is therefore achieved by a method for depositing nano-objects on a receiving surface, the method comprising a first step of picking up such nano-objects located on a carrying surface, a step of transferring said picked up nano-objects to a receiving surface, and a step of depositing said nano-objects on the receiving surface, the method being characterized in that it uses a cantilever transfer device comprising two spaced-apart arms arranged to pick up, hold and release the nano-objects.

[0015] Other advantageous and non-limiting features of the invention may be combined with the first or second aspect 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, onto a receiving surface, the deposition method comprising a first step for picking up such a nano-object or at least one nano-object or at least one carbon nanotube arranged on a carrier surface, in particular a cantilever chip or a cantilever semiconductor chip.

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

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

[0019] When the method according to the invention is implemented for depositing at least one nano-object or at least one carbon nanotube, the carrier surface may comprise a cantilevered semiconductor chip.

[0020] When the method according to the invention is implemented for fastening at least one nano-object or at least one carbon nanotube, the carrier surface may comprise a cantilevered semiconductor chip.

[0021] The deposition method according to the invention can advantageously be implemented for depositing at least one nanotube, preferably at least one carbon nanotube, on the electrode separation trenches.

[0022] Preferably, during the step of depositing at least one nano-object or nanotube or several nanotubes, the arm of the cantilever transfer device penetrates two grooves surrounding the electrode.

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

[0024] Using the deposition method described herein, nano-objects or nano-tubes can be deposited on circuits with inter-electrode trench widths of less than 100 μm, typically 30 μm.

[0025] Preferably, a step is provided for detecting when the cantilever transfer device has come into contact with the receiving surface, such detection step implementing an atomic force probe comprising a tuning fork or mechanical resonator carrying the end of the cantilever transfer device and attached to a frequency controlled around a predetermined resonant frequency.

[0026] Preferably, the detection step comprises a step for providing distance information between the end of the carrier boom transfer device and the receiving surface, said distance information being processed to control the transfer step.

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

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

[0029] According to any embodiment, the method may be implemented in the production of a qubit component.

[0030] According to another aspect of the invention, a system for depositing at least one nano-object on a receiving surface is proposed, the system implementing the deposition method according to the invention and comprising a mechanism for picking up such a nano-object located on a carrying surface, preferably a cantilever chip, a mechanism for transferring the picked-up nano-object to a receiving surface and a mechanism for depositing the nano-object on the receiving surface. The system comprises at least one cantilever transfer device or at least one transfer fork as the picking mechanism, transfer mechanism and deposition mechanism, the at least one cantilever transfer device or at least one transfer fork comprising two spaced-apart arms arranged to pick up, hold and release the nano-object.

[0031] In particular, a deposition system for depositing nano-objects on a receiving surface is proposed, which deposition system implements a deposition method according to the invention and comprises a mechanism for picking up such nano-objects located on a carrying surface.

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

[0033] Preferably, the cantilever transfer means may be in the form of two substantially parallel blades separated by an insulating member.

[0034] For example, each blade may include an elongate portion having a cantilevered end with an arm substantially perpendicular to the elongate portion.

[0035] The arms may include a conductive coating.

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

[0037] Preferably, the width of the grooves between the electrodes is less than 100 μm.

[0038] Preferably, the system is implemented in a system for fastening nanotubes, in particular carbon nanotubes, to a plurality of electrodes of an electronic circuit of quantum dots.

[0039] In a particular implementation of the invention, a system for fastening nanotubes, in particular carbon nanotubes, to a plurality of electrodes is proposed, comprising a deposition system according to the invention, fastening means and means for receiving an electronic circuit of quantum dots.

[0040] Preferably, the system further comprises a mechanism for detecting when the cantilever transfer device has contacted or is at risk of contacting a receiving surface, the detection mechanism comprising an atomic force probe having an end carrying the cantilever transfer device and attached to a tuning fork whose frequency is controlled near a predetermined resonant frequency.

[0041] Preferably, the detection mechanism further comprises a mechanism for outputting deviation information between the tip of the carrying cantilever transfer device and the receiving surface, and further comprises a mechanism for controlling the transfer mechanism based on the deviation information.

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

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

[0044] The present invention involves transferring the carbon nanotubes onto a single small cantilever intermediate. This allows for smaller trenches, saving space on the chip and facilitating future upgrades to the design.

[0045] References

[0046] [1] "One-step Direct Transfer of Pristine Signe-Walled CarbonNanotubes for Functional Nanoelectronics", Chung Chiang Wu et al., Nanoletters, 2010

[0047] [2] "Fork stamping of pristine carbon nanotubes onto ferromagnetic contacts for spin-valve devices", J.Gramich et al., Phys.Status, 2015

[0048] [3] “Transfer of carbon nanotubes onto microactuators for hysteresis-free transistors at low thermal budget”, M. Muoth and C. Hierold, 2012 25th IEEE International Conference on Microelectromechanical Systems (MEMS), 2012, pp. 1352-1355, doi:10.1109 / MEMSYS.2012.6170417

[0049] [4] MicroMegascope (Canale et al.), arXiv:1805.05231v1 [physics.ins-det], 14 May 2018 BRIEF DESCRIPTION OF THE DRAWINGS

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[0074] refer to Figure 7 and Figure 8 We will first describe an example of a cantilever transfer device 3. This transfer device 3 comprises two elongated blades 310, 320 separated by a piece of insulating material. The two blades 310, 320 have curved arms 31, 32 at one end and a portion at the other end for attachment to a mechanical fastening device (not shown) located in a fastening chamber.

[0075] The cantilever transfer device 3 is designed to pick up the carbon nanotubes 4 arranged on the cantilevers 41, 42 of the support structure 23, Fig. 9 and Fig.10 .

[0076] When the arms 31, 32 of the cantilever transfer device 3 come into contact with the nanotube 4, the latter is held in place by van der Waals forces. Figure 11 to Figure 12 , the transfer device 3 can then bring the nanotubes to the receiving structure. Fig.13 , Fig.14 and Fig.17 As shown, the cantilever transfer device 3 carrying the nanotube 4 approaches a receiving structure housing an electronic chip 5 arranged between two grooves and then deposits the nanotube 4 on the chip 5 .

[0077] It should be noted that if Fig.15 and Fig.16As shown, the transfer and deposition technique provided by the present invention makes it possible to significantly reduce the groove width of the receiving structure. This makes it possible to switch from a groove width of about 3 mm to a groove width of about 30 μm. In this way, the receiving chip 5 is positioned on the protrusion 26 between two very thin grooves. Then, the nanotubes 4 can be deposited on the receiving chip 5 arranged between the two grooves 41, 42 and connected to the circuit 6 arranged on the receiving structure 20, as shown in FIG. Fig.16 shown.

[0078] 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 out" the nanotube between two cantilevers suspended on a cantilever growth chip with a comb-like structure. After this transfer, the nanotube is attached to the end of the fork, suspended between two tines. The fork with the nanotube attached is then contacted with the chip of the qubit device to accurately transfer this nanotube to the source and drain electrodes suspended above the gate electrode array. A more detailed overview of the intermediate fork design and the transfer process is given below.

[0079] 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 made of insulating materials such as silicon or silicon nitride (the specific materials are irrelevant) using conventional photolithography and etching techniques. The ends of the tines must be metallized and electrically connected to the flares of the support base by evaporated coating or photolithography. This connection is essential for the second transfer process of the qubit chip and can also facilitate the first transfer of the growing chip.

[0080] The width of the fork is limited by the space between the cantilever pairs that need to be mounted on the growth chip for the first transfer (approximately 30 μm). The gap between the fork tines must be large enough to allow the outermost qubit device electrodes to make the second transfer between the tines (approximately 10 μm). The tines must also be long enough so that the ends of the fork can be easily resolved with an optical microscope at a small angle to the normal (approximately 2 degrees), such as Fig.13 The tines must also be much longer than the thickness of the growing cantilever and the depth of the grooves / pits on the qubit chip to facilitate easy transfer of the nanotubes. Therefore, tines with lengths on the order of 100 μm to 500 μm are required. Finally, the tines must be thick enough to provide a large enough surface area for the nanotubes to attach to the end of the tine during the first transfer, and should therefore be approximately 10 μm thick. This thickness also affects the mechanical strength of the tine, which is designed to survive multiple nanoassembly cycles.

[0081] The first transfer begins by optically aligning the tip of the fork over the location of the target nanotube suspended between two cantilevers on the growth chip. Once aligned, the fork is lowered, bringing the metallized tip of the fork into contact with the suspended nanotube.

[0082] refer to Figures 18 to 24 We will now describe a specific embodiment of a fastening system according to the present invention that provides detection of contact of a cantilever transfer device with a receiving surface and implements an atomic force microscopy architecture.

[0083] Document WO2021009290A1 (Niguès et al.) discloses an atomic force microscope for evaluating a sample surface, the atomic force microscope comprising: a sample holder having a first area suitable for receiving a fixedly mounted sample; a probe having an end suitable for positioning facing the sample surface, the microscope being configured to allow the position of the end to be adjusted relative to the surface; and a support, the sample holder having at least one second area that is different from the first area and is fixed relative to the support, the sample holder being deformable so as to allow relative displacement of the first area relative to the second area, and the microscope comprising a detector suitable for detecting displacement of the first area relative to the second area.

[0084] The MicroMegascope document (Canale et al., 2018, [4]) discloses an atomic force imaging device with a centimeter-scale oscillator. This device uses a centimeter-sized tuning fork or mechanical resonator equipped with an accelerometer to measure the resonator oscillations, thereby producing nanometer-resolution topographic images.

[0085] AFM (atomic force microscopy) technology can be used to detect when the tip of the cantilever approaches a groove. The problem is that this requires substantial changes to the cantilever design. In AFM technology, the oscillator is very small and difficult to integrate into any design.

[0086] refer to Fig.23 and Fig.24 , the fastening system comprises a forked transfer probe 10 coupled to a tuning fork (or mechanical resonator) and a nanopositioner assembly 200. In order to utilize AFM detection during the transfer process, the forked probe 10 in the form of a microchip attached to a printed circuit board 100 is attached to the end 121 of the tuning fork or mechanical resonator, which is inspired by the micromegascope described in the aforementioned document [4], which is mounted on a stack 130 of x / y / z nanopositioning motors.

[0087] The vibration of the tuning fork 200 is driven by a piezoelectric actuator 120 mounted on the top of the tuning fork 200. A MEMS (micro-electromechanical system) accelerometer chip 122 attached to one side of the tuning fork 200 near the tip is used to detect the movement of the tuning fork 200. When attached to the end of the tuning fork 200, the fork-shaped probe 10 will transduce the interaction between its tip and the surface / nanotube during the transfer process, disturbing the vibration of the tuning fork 200.

[0088] These vibration changes of the tuning fork 200 are then measured by the accelerometer and electrically encoded. A phase-locked loop (PLL) controller (external electronics, not shown) is used to retract and extend the nanopositioning motor along the z-axis based on the signal from the accelerometer 122. The phase-locked loop PLL can then be configured to trigger an alarm when the end of the forked transfer probe 10 contacts the nanotube or surface 20, and avoid collision by maintaining a safe separation between the end of the probe 10 and the surface of the quantum circuit chip.

[0089] Of course, the invention is not limited to the examples that have just been described 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 initially being located on a cantilever chip having a comb-like structure, It is characterized in that The method comprises: - a step of picking up the nano-object (4), the picking up step being implemented by a cantilever device or transfer fork (3), said cantilever device or transfer fork comprising two spaced arms (31, 32), each arm being provided with tines, said two tines facing each other and being arranged to pick up, hold and release said nano-object (4), - a step of transferring said picked-up nano-objects (4) to said receiving surface (20), and - A step of depositing said nano-objects (4) on said receiving surface (20).

2. Deposition method according to the preceding claim for depositing at least one nano-object (4) on an electrode separation trench.

3. Deposition method according to the preceding claim, characterized in that During the step of depositing the at least one nano-object, the arm of the cantilever transfer device penetrates into two grooves surrounding an electrode.

4. Deposition method according to the preceding claim, characterized in that The width of the grooves between the electrodes is less than 100 μm.

5. Deposition method according to any one of the preceding claims, characterized in that The deposition method further comprises a step of detecting when the cantilever transfer device (30) has come into contact with the receiving surface (20), the detection step being implemented by an atomic force probe (1) comprising an end (10) carrying the cantilever transfer device (30) and attached to a tuning fork or mechanical resonator (11, 12) whose frequency is controlled near a predetermined resonant frequency.

6. Deposition method according to the preceding claim, characterized in that The detection step comprises a step of providing distance information between the end (10) carrying the cantilever transfer device (30) and the receiving surface (20), the distance information being processed to control the transfer step.

7. Deposition method according to the preceding claim, used for depositing at least one carbon nanotube (4) on a microelectronic circuit (20).

8. Deposition method according to the preceding claim, characterized in that The step of transferring the at least one carbon nanotube (4) is arranged to deposit the at least one carbon nanotube on an electrode.

9. Deposition method according to any one of the preceding claims, characterized in that The deposition method 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), said system implementing a deposition method according to any of the preceding claims, said system comprising means (3) for picking up the nano-object located on a carrying 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), and comprising at least one cantilever transfer device (3) as said picking up device, said transfer device and said deposition device, said at least one cantilever transfer device comprising two spaced-apart arms (31, 32), each arm being provided with tines, which face each other and are arranged to pick up, hold and release the nano-object (4), It is characterized in that The cantilever transfer device (3) takes the form of two substantially parallel blades (310, 320) separated by an insulating member (33).

11. Deposition system (10) according to the preceding claim, characterized in that Each blade (310, 320) includes an elongated portion having a cantilevered end with an arm substantially perpendicular to the elongated portion.

12. Deposition system according to the preceding claim, characterized in that The arms have a conductive coating.

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

14. Deposition system according to the preceding claim, characterized in that The width of the grooves between the electrodes is less than 100 μm.

15. The deposition system according to any one of claims 10 to 14, characterized in that The deposition system is implemented in a system for fastening nanotubes to multiple electrodes of an electronic circuit of quantum dots.

16. The deposition system according to any one of claims 10 to 15, characterized in that The deposition system further comprises means (1) for detecting when the cantilever transfer device (3, 30) has come into contact with the receiving surface (20) or is at risk of coming into contact with the receiving surface, these detection means comprising an atomic force probe (1) having an end (10) carrying the cantilever transfer device (3, 30) and attached to a tuning fork (11, 12) whose frequency is controlled around a predetermined resonant frequency.

17. Deposition system (2) according to the preceding claim, characterized in that The detection mechanism further comprises a mechanism for outputting deviation information between the end (10) carrying the cantilever transfer device (3, 30) and the receiving surface (20), and further comprises a mechanism for controlling the transfer mechanism based on the deviation information.

18. Deposition system according to the preceding claim, characterized in that The deposition system is disposed in a secure chamber within a system for producing qubit components.

19. A system for fastening carbon nanotubes to produce qubit components, the system comprising a fastening chamber incorporating a deposition system according to any one of the three preceding claims.

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