Quantum dot device, preparation method thereof and electronic equipment
By adjusting the ion implantation concentration in quantum dot devices and using FDSOI substrates, the difficulties in controlling traditional silicon-based MOS quantum bits have been solved, achieving more efficient quantum bit coupling and stable device control effects.
Patent Information
- Application Number
- CN202510584303.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-07
- Publication Date
- 2025-09-05
AI Technical Summary
The quantum dots of traditional silicon-based MOS quantum bits are difficult to manipulate, especially the middle position, which affects the overall control effect and calculation accuracy of the device.
The ion injection concentration in the quantum dot region of the quantum dot device is lower than that in the non-quantum dot region. By adjusting the local channel concentration to improve the coupling efficiency between quantum bits, a deeper energy valley is formed using the FDSOI substrate and multiple ion injection processes to facilitate carrier capture and tunneling.
Under the same gate voltage, the gate voltage requirement of the quantum dot area is reduced to achieve easier tunneling and carrier capture, improve the coupling efficiency between quantum bits, and stabilize the control effect of the device.
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Figure CN120603296A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of semiconductor technology, and in particular to a quantum dot device, a preparation method thereof, and an electronic device. Background Art
[0002] Quantum computers use quantum bits (qubits), which can be in a superposition of both 0 and 1 simultaneously. This allows quantum computers to perform parallel computations in certain situations. In quantum computing, qubits must interact and communicate with each other to perform quantum gate operations and transmit quantum information. Quantum dot coupling can achieve this coupling between qubits, allowing them to influence each other and transmit quantum information.
[0003] Traditional silicon-based MOS qubits are usually made based on the FinFET process. The control of quantum dots in this qubit layout can only be adjusted by adjusting the voltage between the source and drain on both sides. There will be a significant difference in the gate voltage and threshold voltage at different positions. The control of quantum dots in the middle position will become very difficult, which will affect the overall control effect and calculation accuracy of the device. Summary of the Invention
[0004] The purpose of the embodiments of the present disclosure is to provide a quantum dot device and a preparation method thereof, and an electronic device to solve the problems existing in the prior art.
[0005] The embodiments of the present disclosure adopt the following technical solution: a quantum dot device, wherein the ion injection concentration in the quantum dot region of the quantum dot device is lower than the ion injection concentration in the non-quantum dot region.
[0006] In some embodiments, the quantum dot region is a gate control region in the channel region of the quantum dot device, and the non-quantum dot region is other regions in the channel region excluding the gate control region.
[0007] In some embodiments, the quantum dot device has a FDSOI substrate.
[0008] The embodiments of the present disclosure also provide a method for preparing a quantum dot device as described above, which at least includes: providing a substrate; injecting ions into a channel region on a surface of one side of the substrate, so that the ion injection concentration of the quantum dot region in the channel region is lower than the ion injection concentration of the non-quantum dot region.
[0009] In some embodiments, the ion injection into the channel region on one side surface of the substrate so that the ion injection concentration of the quantum dot region in the channel region is lower than the ion injection concentration of the non-quantum dot region includes: performing a first ion injection into the channel region; forming a first mask on the surface of the channel region, the first mask being used to cover the quantum dot region; performing a second ion injection into the channel region; and removing the first mask.
[0010] In some embodiments, the ion injection into the channel region on the surface of one side of the substrate so that the ion injection concentration of the quantum dot region in the channel region is lower than the ion injection concentration of the non-quantum dot region includes: forming a first mask on the surface of the channel region, the first mask being used to cover the quantum dot region; performing a first ion injection into the currently exposed surface of the channel region so that the non-quantum dot region has a first ion concentration; removing the first mask and forming a second mask on the surface of the channel region, the second mask being used to cover the non-quantum dot region; performing a second ion injection into the currently exposed surface of the channel region so that the quantum dot region has a second ion concentration, the second ion concentration being less than the first ion concentration; and removing the second mask.
[0011] In some embodiments, providing a substrate includes: providing an FDSOI wafer as the substrate; or, sequentially preparing a buried oxide layer and a second semiconductor layer on one side surface of the first semiconductor layer to form the substrate, and the thickness of the second semiconductor layer is less than the thickness of the first semiconductor layer.
[0012] In some embodiments, the method further includes: sequentially preparing source and drain regions, a gate dielectric layer, a gate interconnection metal, and a source and drain interconnection metal.
[0013] An embodiment of the present disclosure also provides an electronic device, which at least includes the quantum dot device as described above.
[0014] In some embodiments, the electronic device includes at least a computer, a mobile phone, a tablet, a vehicle-mounted device, a smart wearable device, a digital camera, a personal digital assistant, and a media player.
[0015] The beneficial effects of the embodiments of the present disclosure are: by targetedly increasing the ion injection concentration in the non-quantum dot area, the gate voltage required to achieve inversion in the quantum dot area is reduced under the same gate voltage. Under the same gate voltage, a deeper energy valley is formed in the quantum dot area, which makes tunneling easier to achieve. At the same time, the deeper energy valley is also convenient for capturing carriers, thereby improving the efficiency of coupling between quantum bits, providing more convenient conditions for quantum dot coupling manipulation, and achieving the purpose of overall manipulation effect and stable device function. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In order to more clearly illustrate one or more embodiments of this specification or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0017] Figure 1 A partial hierarchical cross-sectional diagram of a quantum dot device in the first embodiment of the present disclosure;
[0018] Figure 2 Schematic diagram of current transport of the quantum dot device during actual operation in the first embodiment of the present disclosure;
[0019] Figure 3 : is the current bias triangle of the quantum dot device in the first embodiment of the present disclosure;
[0020] Figure 4 This is a flow chart of a method for preparing a quantum dot device in the second embodiment of the present disclosure;
[0021] Figures 5 to 7 Schematic diagram of the implementation process of the first channel region ion implantation method in the second embodiment of the present disclosure;
[0022] Figures 8 to 11 Schematic diagram of the implementation process of the second channel region ion implantation method in the second embodiment of the present disclosure. DETAILED DESCRIPTION
[0023] In order to enable those skilled in the art to better understand the technical solutions in one or more embodiments of this specification, the technical solutions in one or more embodiments of this specification will be clearly and completely described below in conjunction with the drawings in one or more embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on one or more embodiments of this specification, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this document.
[0024] Quantum computers use quantum bits (qubits), which can be in a superposition of both 0 and 1 simultaneously. This allows quantum computers to perform parallel computations in certain situations. In quantum computing, qubits must interact and communicate with each other to perform quantum gate operations and transmit quantum information. Quantum dot coupling can achieve this coupling between qubits, allowing them to influence each other and transmit quantum information.
[0025] Traditional silicon-based MOS qubits are usually made based on the FinFET process. The control of quantum dots in this qubit layout can only be adjusted by adjusting the voltage between the source and drain on both sides. There will be a significant difference in the gate voltage and threshold voltage at different positions. The control of quantum dots in the middle position will become very difficult, which will affect the overall control effect and calculation accuracy of the device.
[0026] In order to solve the above problems, the first embodiment of the present disclosure provides a quantum dot device, which can have a conventional transistor structure, for example, including a substrate, a channel region, a source-drain region, a gate dielectric, a gate interconnect metal, a source-drain interconnect metal, etc. In this embodiment, the ion implantation concentration of the quantum dot region of the quantum dot device is lower than the ion implantation concentration of the non-quantum dot region. Figure 1 In the schematic diagram of a partial hierarchical cross-section of a quantum dot device shown, the horizontally shaded area represents quantum dot region 1, and the diagonally shaded area represents non-quantum dot region 2. Both quantum dot region 1 and non-quantum dot region 2 are located in a channel region 20, which is fabricated on the surface of substrate 10. Under the same gate voltage, the gate voltage required to achieve inversion in the quantum dot region is reduced. While the gate voltage remains unchanged, the barrier between the quantum dot region and the non-quantum dot region is raised, making tunneling easier. The deeper energy valley also facilitates carrier capture, thereby improving the efficiency of coupling between qubits and providing more convenient conditions for controlling quantum dot coupling, achieving overall control effectiveness and stable device function.
[0027] It should be noted that the specific difference in ion concentration between the quantum dot region and the non-quantum dot region can be tailored to the specific process requirements, annealing temperature, device size requirements, and actual control effects, and is not specifically limited in this embodiment. Furthermore, the specific type of ion implanted also depends on the type of device required, and the appropriate ion implantation can be selected based on the type of quantum dot device being used.
[0028] In this embodiment, the quantum dot region primarily refers to the gate-controlled region within the device's channel region, i.e., the area of the channel region directly facing or affected by the gate. The quantum dot region is the region of the channel region excluding the gate-controlled region, i.e., the area of the channel region not directly affected by the gate. By adjusting the local channel concentration to improve the efficiency of inter-qubit coupling, qubit coupling can be controlled, providing more convenient conditions for adjusting source, drain, and gate voltages to achieve quantum dot coupling control.
[0029] In some embodiments, the quantum dot device has a FDSOI substrate, such as Figure 1As shown, the substrate 10 is an FDSOI substrate, which is actually a single crystal silicon (Si), a buried oxide layer (BOX) and a top silicon layer arranged in sequence from bottom to top. When the device is actually prepared, the top silicon layer is used as the active area for ion implantation in the channel area and the source and drain area.
[0030] In some embodiments, the semiconductor material layer of the FDSOI substrate may be made of semiconductor materials other than silicon, for example, it may be made of one or more of silicon-28, germanium, gallium arsenide, silicon germanium, gallium aluminum arsenide, gallium indium arsenide and their dopants. Figure 1 The positions, sizes, cross-sectional shapes, etc. of the quantum dot region and the non-quantum dot region shown in the figure are merely examples and can be adjusted according to the actual preparation process and requirements, and are not specifically limited in this embodiment. At the same time, the specific shape of the active area is not shown in the figure, and it can be any one of a rectangle, square, diamond, and circle, which is not specifically described in this embodiment.
[0031] Figure 2 A schematic diagram of current transport of the quantum dot device of this embodiment during actual operation is shown. As can be seen from the figure, the quantum dot device of this embodiment improves the ability to capture carriers, thereby facilitating the coupling of dual quantum dots or even multiple quantum dots. Figure 3 The current bias triangle of the quantum dot device of this embodiment is shown, and bit coupling is achieved through the current bias triangle, thereby reflecting the excellent performance of the quantum dot device of this embodiment.
[0032] This embodiment specifically increases the ion injection concentration in the non-quantum dot region, and reduces the gate voltage required to achieve inversion in the quantum dot region under the same gate voltage. Under the same gate voltage, a deeper energy valley is formed in the quantum dot region, which makes tunneling easier. At the same time, the deeper energy valley is also easier to capture carriers, thereby improving the efficiency of coupling between quantum bits, providing more convenient conditions for quantum dot coupling manipulation, and achieving the overall manipulation effect and stable device function.
[0033] Based on the same inventive concept, the second embodiment of the present disclosure provides a method for preparing a quantum dot device as provided in the first embodiment, and its flow chart is as follows: Figure 4 As shown, it at least includes the following steps:
[0034] S1, providing a substrate;
[0035] S2, injecting ions into the channel region on one surface of the substrate so that the ion implantation concentration in the quantum dot region within the channel region is lower than the ion implantation concentration in the non-quantum dot region.
[0036] In this embodiment, the substrate provided in step S1 can be an FDSOI wafer, or a buried oxide layer and a second semiconductor layer can be prepared in sequence on one side surface of the first semiconductor layer to form a substrate, and the thickness of the second semiconductor layer is less than the thickness of the first semiconductor layer, and the two can be prepared based on the same semiconductor material.
[0037] When actually executing step S2, it can be implemented in different ways. Figures 5 to 11 The ion implantation process in the channel region is described in detail. It should be noted that: Figures 5 to 11 The top silicon layer in the FDSOI substrate of the silicon base is used as the channel region.
[0038] Steps S21 to S24 illustrate one of the channel region ion implantation methods of this embodiment, specifically:
[0039] S21, performing the first ion implantation into the channel region; Figure 5 As shown, without setting a mask, the first ion injection is performed simultaneously to the quantum dot region and the non-quantum dot region. At this time, the ion concentrations in the quantum dot region and the non-quantum dot region are the same;
[0040] S22, forming a first mask on the surface of the channel region, the first mask is used to cover the quantum dot region; Figure 6 As shown, the first mask 31 is used to cover the quantum dot region in the channel region to facilitate the second ion implantation in the non-quantum dot region;
[0041] S23, a second ion implantation is performed into the channel region; Figure 7 As shown, at this time, ions are only injected into the non-quantum dot area, so that the ion injection concentration in the quantum dot area is lower than the ion injection concentration in the non-quantum dot area;
[0042] S24, removing the first mask.
[0043] Steps S25 to S29 illustrate another channel region ion implantation method of this embodiment, specifically:
[0044] S25, forming a first mask on the surface of the channel region, the first mask is used to cover the quantum dot region; Figure 8 As shown, the first mask 31 is used to cover the quantum dot region in the channel region to facilitate ion implantation in the non-quantum dot region;
[0045] S26, performing a first ion implantation on the currently exposed surface of the channel region so that the non-quantum dot region has a first ion concentration; Figure 9 As shown;
[0046] S27, removing the first mask and forming a second mask on the surface of the channel region, the second mask being used to cover the non-quantum dot region; Figure 10 As shown, the second mask 32 is used to cover the non-quantum dot region in the channel region to facilitate ion implantation in the quantum dot region;
[0047] S28, performing a second ion implantation on the currently exposed surface of the channel region, so that the quantum dot region has a second ion concentration, which is less than the first ion concentration; Figure 11 As shown;
[0048] S29, removing the second mask.
[0049] It should be noted that the above two methods are specific methods used to achieve different ion implantation concentrations in the quantum dot region and the non-quantum dot region. In the actual preparation process, other methods that can achieve the same effect can also be used. This embodiment does not specifically limit this. At the same time, the process for implementing ion implantation can be implemented using various processes such as cold implantation. This embodiment does not limit the specific implantation method. In addition, the etching processes used in the process of implementing ion implantation include but are not limited to dry etching, wet etching, electron beam lithography, etc., and the heat treatment processes include but are not limited to rapid thermal annealing, laser annealing, etc. The above etching and heat treatment steps can be implemented in accordance with the lithography and heat treatment requirements of the existing ion implantation process flow.
[0050] In actual implementation, after the quantum dot region and the non-quantum dot region of the channel layer are prepared, the required layers of the device, such as the source and drain region, the gate dielectric layer, the gate interconnection metal, and the source and drain interconnection metal, should be prepared in sequence. These layers can be directly implemented according to the existing process flow, and finally form a Figure 1 The quantum dot device shown.
[0051] This embodiment specifically increases the ion injection concentration in the non-quantum dot region, and reduces the gate voltage required to achieve inversion in the quantum dot region under the same gate voltage. Under the same gate voltage, a deeper energy valley is formed in the quantum dot region, which makes tunneling easier. At the same time, the deeper energy valley is also easier to capture carriers, thereby improving the efficiency of coupling between quantum bits, providing more convenient conditions for quantum dot coupling manipulation, and achieving the overall manipulation effect and stable device function.
[0052] Based on the same inventive concept, a third embodiment of the present disclosure provides an electronic device that includes at least the quantum dot device of the first embodiment of the present disclosure, thereby implementing quantum computing capabilities. Specifically, the electronic device of this embodiment can be any of a computer, a mobile phone, a tablet, an in-vehicle device, a smart wearable device, a digital camera, a personal digital assistant, and a media player.
[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present disclosure.
Claims
1. A quantum dot device, characterized in that: The ion implantation concentration in the quantum dot region of the quantum dot device is lower than the ion implantation concentration in the non-quantum dot region.
2. The quantum dot device according to claim 1, characterized in that The quantum dot region is a gate control region in the channel region of the quantum dot device, and the non-quantum dot region is other regions in the channel region except the gate control region.
3. The quantum dot device according to claim 1 or 2, characterized in that The quantum dot device has an FDSOI substrate.
4. A method for preparing a quantum dot device according to any one of claims 1 to 3, characterized in that: At least: providing a substrate; Ions are implanted into a channel region on one side surface of the substrate, so that the ion implantation concentration of the quantum dot region in the channel region is lower than the ion implantation concentration of the non-quantum dot region.
5. The preparation method according to claim 4, characterized in that The step of injecting ions into the channel region on one side of the substrate so that the ion implantation concentration of the quantum dot region in the channel region is lower than the ion implantation concentration of the non-quantum dot region includes: performing a first ion implantation into the channel region; forming a first mask on the surface of the channel region, wherein the first mask is used to cover the quantum dot region; performing a second ion implantation into the channel region; The first mask is removed.
6. The preparation method according to claim 4, characterized in that The step of injecting ions into the channel region on one side of the substrate so that the ion implantation concentration of the quantum dot region in the channel region is lower than the ion implantation concentration of the non-quantum dot region includes: forming a first mask on the surface of the channel region, wherein the first mask is used to cover the quantum dot region; Performing a first ion implantation on the currently exposed surface of the channel region so that the non-quantum dot region has a first ion concentration; Removing the first mask and forming a second mask on the surface of the channel region, wherein the second mask is used to cover the non-quantum dot region; Performing a second ion implantation on the currently exposed surface of the channel region so that the quantum dot region has a second ion concentration, wherein the second ion concentration is less than the first ion concentration; The second mask is removed.
7. The preparation method according to claim 4, characterized in that The method provides a substrate, comprising: Providing an FDSOI wafer as the substrate; or, A buried oxide layer and a second semiconductor layer are sequentially formed on one side surface of the first semiconductor layer to form the substrate, wherein the thickness of the second semiconductor layer is smaller than that of the first semiconductor layer.
8. The preparation method according to any one of claims 4 to 7, characterized in that Also includes: The source and drain regions, the gate dielectric layer, the gate interconnection metal and the source and drain interconnection metal are prepared in sequence.
9. An electronic device, characterized in that: At least comprising the quantum dot device according to any one of claims 1 to 3.
10. The electronic device according to claim 9, characterized in that At least include computers, mobile phones, tablets, car devices, smart wearable devices, digital cameras, personal digital assistants, and media players.