Large-area / wafer-scale cmos-compatible 2d-material intercalation doping tools, processes, and methods, including doping of synthesized graphene

Abstract

An intercalation doping apparatus includes: a reaction chamber for placing a single or plurality of wafers or substrates therein and for applying a pressure in the range of 2 bar to 500 bar to at least one surface of the single or plurality of wafers or substrates within the reaction chamber, wherein the single or plurality of wafers or substrates have a diameter or side margin of 25 mm to 450 mm; a heater for applying thermal energy to the single or plurality of wafers or substrates to a temperature including 25 °C to 500 °C; and a dopant application device, including at least a valve and conduit for bringing dopant from the outside into the reaction chamber, and at least one dopant crucible disposed within the reaction chamber, wherein the dopant comprises a material in a solid phase, liquid phase, or gas phase, and includes an intercalation dopant.

Description

Technical Field

[0001] This application refers to U.S. Patent Application No. 17 / 863,232, filed July 12, 2022, entitled "LOW-TEMPERATURE / BEOL-COMPATIBLE HIGHLY SCALABLE GRAPHENE SYNTHESIS TOOL"; U.S. Patent Application No. 17 / 857,954, filed July 5, 2022, entitled "LOW-TEMPERATURE / BEOL-COMPATIBLE HIGHLY SCALABLE GRAPHENE SYNTHESIS TOOL"; and U.S. Provisional Patent Application No. 63 / 218,498, filed July 6, 2021, entitled "WAFER-SCALE CMOS-COMPATIBLE GRAPHENE SYNTHESIS TOOL". The entire contents of these applications are incorporated herein by reference.

[0002] Furthermore, this application claims priority to U.S. Patent Application No. 18 / 527,043, filed December 1, 2023, which claims domestic priority to U.S. Provisional Application No. 63 / 441,766, filed January 27, 2023, entitled "LARGE-AREA / WAFER-SCALE CMOS-COMPATIBLE 2D-MATERIAL DOPING TOOLS, PROCESSES, AND METHODS, INCLUDING DOPING OF SYNTHESIZED GRAPHENE." The entire contents of the latter are incorporated herein by reference. Prior Technology

[0003] In many applications, including microelectronics, the conductivity of atomically thick two-dimensional (2D) layered materials (including synthetic multilayer graphene (MLG)) or any layered semiconductor material (such as molybdenum disulfide (MoS2) or tungsten disulfide (WS2)) needs to be modulated. Typically, this modulation involves increasing the carrier concentration of electrons, holes, or other charge carriers. This carrier concentration can be increased through a process called doping, which involves inserting or adsorbing certain atoms or molecules into the host material, thereby inducing charge transfer between the dopant and the material (e.g., MLG). In some cases, dopant can be designed to be placed at specific crystal sites to induce electroactivity or ionization (resulting in an excess of electrons or holes). Some dopant may require thermal annealing to move; for example, applying heat energy can be used to move dopant, such as arsenic (As) atoms in single-crystal silicon, from interstitial sites in silicon to alternative crystal sites. To integrate MLG / layered material doping processes into CMOS fabrication technologies, a dedicated large-area (200 / 300 / 450 / XXX mm) reactor needs to be designed. This reactor must also be able to operate within the current and anticipated back-end-of-line (BEOL) thermal budget (<450 °C) and high pressure (1-500 bar) range. This doping acceleration can be generated by temperature or pressure, or a combination of both.

[0004] In the realm of atomically thin two-dimensional (2D) materials, particularly graphene or MLG (essentially single or multiple atomic layers of carbon atoms arranged in a hexagonal lattice), it is now possible to synthesize directly on desired substrates (typically dielectrics or metals). Previous techniques required a transfer step (depositing graphene / MLG onto the desired substrate after synthesis on a metal catalyst film), which was considered infeasible and cost-inefficient in mainstream electronics manufacturing (or CMOS) due to contamination, defects / wrinkles, and other problems associated with the transferred graphene / MLG. Furthermore, previous techniques presented numerous challenges in doping MLG or other 2D materials using conventional methods. The future leader in interconnect material selection will be graphene / MLG layers, which must be doped to meet certain resistivity targets. These are the materials of choice for various BEOL (back-end process steps in wafer fabrication after the formation of active components such as transistors and diodes), particularly for on-chip interconnects.

[0005] Due to their geometries, such as the layered structure of many 2D materials, intercalation doping can be used to minimize the size requirements of single-layer or multi-layer stacked materials. Intercalation doping refers to the insertion of dopant atoms / molecules from the sidewall surfaces of material layers through diffusion. This method has been shown to be able to dope narrow geometries (linewidths) of two-dimensional materials. Accelerating this doping process by applying temperature and / or pressure can make the doping process usable in manufacturing and reduce costs.

[0006] Widespread applications in microelectronics, optoelectronics, bioelectronics, quantum computing, and antennas (5G / 6G / THz) require doping at relatively low temperatures (<450 °C). However, to enable this doping process for manufacturing, particularly for fabricating components on large "wafer-scale" substrates (e.g., 200 mm, 300 mm, 450 mm, etc.) within a reasonable timeframe, novel devices need to be designed and fabricated. These devices must be able to uniformly apply a wide range of temperatures and pressures across the entire surface area of ​​a semiconductor wafer or other substrate. The core component of such a device is a reactor that not only accommodates such a large substrate area but also provides a chemically purified environment, heats the large substrate with acceptable temperature uniformity, and applies relatively large and uniform pressures (e.g., up to 7000 psi, 500 bar, etc., but within the substrate's fracture limits) to the wafer / substrate using simple mechanisms via gaseous and / or mechanical means. Note that in some examples, atmospheric pressure can be used to apply pressure.

[0007] For example, there is a growing demand for such large-area devices in the emerging field of atomically thin two-dimensional (2D) materials, particularly graphene or MLG. Such graphene / MLG layers are preferred materials for a variety of BEOL applications, especially on-chip interconnects. However, achieving interconnects in BEOLs requires efficient synthesis and doping within a tight thermal budget of <450 °C to avoid any damage to the underlying active components (e.g., damage to transistors, diodes, etc. due to increased impurity diffusion). Therefore, it is crucial to incorporate pressure control to achieve doping at relatively low temperatures within an acceptable timeframe for high-volume manufacturing environments.

[0008] The device and doping technology provided by this invention can also be extended to various substrates, including substrates of different materials (e.g., glass), substrates of different geometries (e.g., square), and substrates with multiple configurations (e.g., multilayers), as well as other applications that require a low thermal budget (< 450 °C) in terms of characteristics. Summary of the Invention

[0009] One aspect of the present invention is to provide an intercalation doping apparatus for inserting dopant atoms, ions, or molecules into a layered 2D material. The apparatus includes: a reaction chamber for placing one or more wafers or substrates within the reaction chamber and for applying a pressure in the range of 2 bar to 500 bar to at least one surface of the single or multiple wafers or substrates within the reaction chamber, wherein the single or multiple wafers or substrates have a diameter or side margin of 25 mm to 450 mm; a heater for applying heat energy to the single or multiple wafers or substrates, wherein the single or multiple wafers or substrates have a temperature of 25 °C to 500 °C; and a dopant application device, the dopant application device including at least a valve and conduit for bringing dopant from the outside into the reaction chamber, wherein the dopant application device includes at least one dopant crucible disposed within the reaction chamber, wherein the dopant comprises a material in a solid, liquid, or gas phase, and wherein the dopant includes an intercalation dopant.

[0010] Another aspect of the present invention is to provide an intercalation doping apparatus for inserting dopant atoms, ions, or molecules into layered 2D materials. The apparatus includes: a reaction chamber for placing a single or plurality of wafers or substrates within the reaction chamber and for applying a pressure in the range of 2 bar to 500 bar to at least one surface of the single or plurality of wafers or substrates within the reaction chamber, wherein the single or plurality of wafers or substrates have a diameter or side margin of 25 mm to 450 mm; a heater for applying heat energy to the single or plurality of wafers or substrates, wherein the single or plurality of wafers or substrates have a temperature of 25 °C to 500 °C; and a dopant application device, the dopant application device including at least a valve and conduit for bringing the dopant from the outside into the reaction chamber, wherein the dopant application device includes at least one dopant crucible disposed within the reaction chamber, wherein the dopant comprises a material in a solid, liquid, or gas phase, and wherein the dopant includes an intercalation dopant, and wherein the single or plurality of wafers or substrates comprise a single-layer, few-layer, or multi-layer graphene ribbon.

[0011] Another aspect of the present invention is to provide an intercalation doping method, wherein the intercalation doping includes using a device to induce dopant atoms, ions, or molecules to intercalate into a layered 2D material, the method comprising: providing a reaction chamber, a heater, and a dopant application device; providing a single or plurality of wafers or substrates, wherein the single or plurality of wafers or substrates are placed in the reaction chamber, wherein the single or plurality of wafers or substrates have a diameter or side margins of 25 mm to 450 mm; and applying heat energy to the single or plurality of wafers or substrates using the heater, wherein the single or plurality of wafers or substrates comprise a temperature range of 25 °C to 500 °C. A temperature of ℃ and a pressure in the range of 2 bar to 500 bar applied to the single or majority wafers or substrates; wherein the dopant application device introduces and / or arranges a dopant into and / or places a dopant in the reaction chamber, wherein the dopant comprises a material in a solid, liquid, or gas phase, wherein the dopant comprises an intercalation dopant, wherein the single or majority wafers or substrates comprise a single layer, a few layers, or multiple layers of graphene ribbon; and the single or majority wafers or substrates are processed at the temperature and the pressure in the presence of at least one of the intercalation dopants. Simple Explanation of the Diagram

[0012] The contents of this invention will become clearer from the following detailed description and with reference to the accompanying drawings. In the drawings, similar elements may be represented by similar element symbols.

[0013] Figure 1A shows an example of the batch / single wafer processing apparatus of the present invention, which is suitable for inserting gaseous dopant atoms or molecules into monolayer, few-layer, or multilayer graphene (MLG) or any other layered or non-layered material by applying gas pressure to the wafer. The material can be synthesized by any method and can have any arbitrary geometry and thickness. Figure 1B shows a schematic diagram of an example device according to some embodiments of the invention similar to the device of Figure 1A, which adds the additional capability of using gas vaporized with solid / liquid dopants while simultaneously pressurizing the gas on the substrate / wafer; Figure 2 shows a schematic diagram of an example apparatus and a process flow diagram of a second embodiment of the present invention. According to some embodiments, this process flow introduces gas into a reaction chamber and pressurizes the dopant (gas or gas obtained by vaporizing a liquid / solid) to dope a single or multiple horizontally placed wafers / substrates. Figure 2A shows a schematic diagram of an example apparatus according to a third embodiment of the present invention. The figure shows that the processing / reaction chamber is located in the apparatus of, for example, Figure 2. According to some embodiments, in addition to other apparatus elements, a piston located above the horizontally placed substrate / wafer is used for non-contact pressure-accelerated doping. Figure 2B shows a schematic diagram of the gas supply system used in Figure 2A; and Figure 3 shows a schematic diagram of an example device according to a third embodiment of the present invention. According to some embodiments, the device pressurizes a gaseous or solid / liquid dopant source (vaporized or unvaporized) in a direct contact mechanical manner.

[0014] The accompanying drawings are illustrative and are not intended to exhaustively list all specific embodiments of the present invention. Implementation

[0015] The systems, methods, and articles disclosed in this invention are applicable to a variety of low-temperature / BEOL-compatible, highly scalable doping tools configured to allow efficient doping of difficult-to-dopant materials. An example of such difficult-to-dopant materials is single-layer and multi-layer high-quality graphene, which is increasingly becoming the material of choice for miniaturization technologies in microelectronic interconnects. The following description is intended to enable those skilled in the art to understand, and to make and use, various embodiments of the invention. Descriptions of specific devices, techniques, and applications are provided by way of example only. Various modifications to the embodiments described herein will be apparent to those skilled in the art. Furthermore, the general principles defined herein can be applied to other examples and applications without departing from the spirit and scope of the various embodiments.

[0016] The terms "an embodiment," "an example," or similar expressions used in this specification refer to specific technical features, structures, or characteristics described in the description of that embodiment, which may be included in at least one embodiment of the present invention. Therefore, the use of the terms "in an embodiment," "in one embodiment," and similar expressions throughout the specification may, but not necessarily, indicate the same embodiment.

[0017] Furthermore, the technical features, structures, or characteristics of the present invention described in this specification can be combined in any suitable manner in one or more embodiments. Numerous specific details, such as programming, software modules, user selection, online transactions, database queries, database structures, hardware modules, hardware circuits, and hardware chips, will be provided in the following description to enable the reader to fully understand the embodiments of the present invention. However, those skilled in the art will recognize that the present invention can be implemented without one or more of these specific details, or using other alternative methods, components, materials, etc. On the other hand, to avoid obscuring various aspects of the invention, well-known structures, materials, or operations are not shown or described in detail.

[0018] The schematic flowcharts included in this specification are generally referred to as logic flowcharts. Therefore, the sequence and labeled steps depicted are merely illustrative of one embodiment of the presented method. The shown method may be understood as being functionally, logically, or effectively equivalent to one or more other steps, or portions thereof, of the method. Furthermore, the format and symbols used in this specification are only for interpreting the logical steps of the method and should not be construed as limiting the scope of the method. While various arrows and lines may be used in the flowcharts, it should be understood that such arrows and lines are not intended to limit the scope of the corresponding method. In fact, some arrows or other lines may also be used to indicate the logical flow of the method. For example, an arrow may indicate a period of waiting or monitoring not shown in the diagram between two steps listed in the depicted method. Furthermore, the order in which a particular method occurs may or may not strictly adhere to the order of the corresponding steps shown.

[0019] [Term Definition]

[0020] Back-End-Of-Line (BEOL): This refers to the second part of the IC manufacturing process. In this part, interconnects and other circuit elements are formed on and between individual devices (mainly transistors) arranged on the wafer (e.g., metallization layers) and isolated by in-layer and / or inter-layer insulators.

[0021] Complementary metal-oxide-semiconductor (CMOS): a metal-oxide-semiconductor field-effect transistor (MOSFET) process that uses complementary and multi-phase electrically symmetrical p-type and n-type MOSFET pairs to implement at least the logic function.

[0022] Grain boundary (GB): refers to the interface between two grains and / or microcrystals in a polycrystalline material.

[0023] Graphene is an allotrope of carbon, consisting of a single layer of atoms arranged in a two-dimensional honeycomb lattice.

[0024] Graphene nanoribbons (GNRs) refer to graphene strips with a width of less than approximately 100 nm.

[0025] Graphite is a layered crystalline form of carbon, with its atoms arranged and covalently bonded within the layers to form a hexagonal structure.

[0026] Intercalation doping: Intercalation refers to the reversible insertion of molecules or ions into a compound. Between layers (e.g., potassium ions inserted between graphite layers). Doping is the addition of impurities to a material. Dopant (impurity ions) integrates into the material's crystal lattice. N-type dopant donates electrons to the material, while P-type dopant accepts electrons from the material. Doping alters the carrier density, thus changing the material's electronic properties.

[0027] Intercalation dopants: Numerous studies have documented this. See recent publications by Kaustav Banerjee et al., which specifically address graphene. For example, J. Jiang, Jae Hwan Chu, and Kaustav Banerjee, "CMOS-Compatible Doped-Multilayer-Graphene Interconnects for Next-Generation VLSI", IEDM 2018, pp. 799-802, 34.5.1-4; and J. Jiang et al., "Intercalation doped multilayer-graphene-nanoribbons for next-generation interconnects", Nano Letters, Vol. 17, No. 3, pp. 1482-1488, 2017.

[0028] Piezoelectricity: refers to the electrical charge that accumulates in certain solid materials in response to applied mechanical stress.

[0029] A resistance temperature detector (RTD) is a sensor that measures temperature by monitoring the change in resistance of a conductor with temperature. An RTD element can be formed from a thin wire wound around a heat-resistant ceramic or glass core, but other structures can also be used.

[0030] Silicon dioxide: It is an oxide of silicon and an insulator with the chemical formula SiO2.

[0031] A wafer is a thin sheet of semiconductors (such as silicon or germanium) used to manufacture integrated circuits.

[0032] [Large area] [ / ] [Wafer Level Low Temperature] [ / BEOL] [First Embodiment of Compatible Highly Scalable Complex Tool] [:batch] [ / ] [single tablet; adulterant] [=] [gas; substrate pressurization] [=] [gas pressurization]

[0033] It should be stated first that the doped materials discussed in the following embodiments are only exemplary in nature. Thus, other doped equipment or methods may be utilized in other exemplary embodiments.

[0034] 1A, Figure 1B, Figure 2, Figure 3, and Figure 4 show several exemplary devices and methods for inserting dopant atoms or molecules in the solid / liquid phase (vaporized or unvaporized) or in the gas phase into a single, minority, or multilayer graphene (MLG), or in any other layered material synthesized using any method with arbitrary geometry and thickness. Among them, Figure 1A shows exemplary Schematic and sample method flow of doping devices for [Batch] (single wafer / substrate can of course also be handled in this device). For example, graphene / MLG doping can be described, for example, using pressure- and temperature-accelerated gas-phase doping, particularly, but not limited to, intercalation doping of MLG. However, the processes and equipment of the present invention are not limited to intercalation doping of MLG, but the equipment can be applied to doping a variety of other materials using other methods.

[0035] As shown in Figure 1A, the batch processing apparatus 100 may include, but is not limited to: a reaction chamber 102, a reaction chamber door and seal 104, a substrate / wafer 105, a paddle 106, a dopant processing gas / mist inlet 108, an internal space of the entire reactor processing chamber 110, a multi-directional high-pressure valve 112, a piston chamber space 114, a pump purging and pressurizing gas 116, a pressurizing / exhausting pump 118, a piston motion shaft 120, a piston chamber 122, a solenoid or screw motor 124, a piston 126, a chamber sidewall heater 130, additional settings 132 for gases 3 and 4 (optional), a pump-to-chamber valve 134, a gas control panel 140, a dopant gas mixing block 142, an MFC (mass flow controller) iso valve - output 146, an MFC (mass flow controller) 148, and an MFC... ISO valve-input 150, gas regulator 152, particulate filter 154, dopant 1 gas cylinder 156, dopant 2 gas cylinder 157, and cleanroom gas supply facility 158.

[0036] The reaction chamber 102 may include a steel-encased pressure vessel capable of withstanding applied pressure and temperature, and a tubular liner that may use, for example, a high-quality, high-purity quartz material. The reaction chamber 102 may include openings, such as a reaction chamber door and seal 104, a dopant treatment gas / mist inlet 108 (which may be integrated with a high-pressure shut-off valve), and an opening connected to a pressurization device via a multi-way high-pressure valve 112. The reaction chamber door and seal 104 may be opened (after the reaction chamber 102 has been vented of toxic gases and atmospheric pressure has been reached) to load the substrate / wafer 105 onto the propeller 106. The propeller 106 may include a quartz boat (not shown) with slots for holding the substrate / wafer 105 in a desired position—typically arranged parallel to each other at a spacing that satisfies uniformity through engineering calculations and considerations. However, there are still many different alternatives for how the substrate and wafer are held and processed. In this example shown in Figure 1, the batch processing apparatus 100 is drawn in a horizontal configuration. As an alternative, the batch processing apparatus 100 can be rotated 90 degrees from the arrangement shown in FIG1 to become a vertical high-pressure processing chamber. The reaction chamber 102 may include a gas movement and exhaust system (not shown) for mixing the input gas and / or providing process gas, which may be located at the end opposite the gas inlet.

[0037] The propeller 106, reaction chamber door and seal 104, and substrate / wafer 105 can be moved together into reaction chamber 102 until the reaction chamber door and seal 104 are closed and sealed. The movement of propeller 106 and the loading of substrate / wafer 105 onto the quartz boat, and then onto propeller 106, can be performed by a robotic arm (not shown) to minimize defect generation (e.g., quartz dust) and human labor requirements. At this point, substrate / wafer 105 is fully positioned within reaction chamber 102. The temperature of substrate / wafer 105 should be at least brought to equilibrium. A composition of dopant gas and / or single or multiple types of gaseous mixtures suitable for doping substrate / wafer 105 is then introduced into reaction chamber 102 via different MFCs. Note that these gases can be preheated, or placed at approximately room temperature (to provide at least part of the required pressurization from a fixed volume of heated gas), and can also be placed under high pressure, or the internal volume of reaction chamber 102 can be placed under part or all of the desired high pressure as is present in the full reactor processing chamber 110. Pressure regulation can be achieved by moving the multi-directional high-pressure valve 112 to the desired position and utilizing the pressurization pump 118 (which provides pressurized gas via pump purging and pressurization gas 116) and opening the pump to chamber valve 134. Alternatively, or in combination, the desired pressure can be obtained by adjusting the pressure of the internal space 110 of the full reactor processing chamber in a volume manner by moving the piston 126 along the piston movement axis 120 using a solenoid or screw motor 124 (for a given T, decreasing V will increase P). The pressure of the dopant gas in the internal space 110 of the full reactor processing chamber will accelerate the injection of dopant atoms into the surfaces and sidewalls of the substrate / wafer 105 structure (e.g., interconnects).

[0038] The accelerated dopant atoms bombard the surface of the substrate / wafer 105. The resulting solid-state diffusion rate on a portion of the substrate / wafer 105 can also be accelerated / enhanced by increasing the temperature of the substrate / wafer 105 and the temperature of the dopant gas introduced into the internal space 110 of the whole reactor processing chamber through the dopant processing gas / mist inlet 108. Heating is achieved, at least via the chamber sidewall heaters 130. Note that the dopant gas injected into the internal space 110 of the whole reactor processing chamber through the dopant processing gas / mist inlet 108 can also be preheated or cooled, as needed, through engineering management and chemical calculations and considerations. The temperature range of the internal space 110 of the whole reactor processing chamber, and the temperature at which at least the substrate / wafer 105 is reached at equilibrium, can be from about 25°C to about 500°C, with a uniformity of less than ±5°C. The internal space 110 of the whole reactor processing chamber can be designed to accommodate substrates / wafers 105 with a diameter of at least 450 mm (if a circular wafer). Conversely, if the substrate is square / rectangular, it accommodates a substrate / wafer 105 with each side measuring 450 mm. The pressure range of the internal space 110 of the entire reactor processing chamber can be approximately 20 psi, approximately 30 psi, approximately 40 psi, approximately 50 psi, approximately 60 psi, approximately 70 psi, approximately 80 psi, approximately 90 psi, approximately 100 psi, approximately 110 psi, approximately 120 psi, approximately 130 psi, approximately 150 psi, approximately 200 psi, approximately 250 psi, approximately 300 psi, approximately 350 psi, approximately 400 psi, approximately 450 psi, and can be greater than approximately 500 psi, or 1-500 bar, depending on engineering management and design objectives, selections, and considerations.

[0039] The acceleration of gas pressure for dopant movement can be achieved in at least four ways: 1) by heating the gas in a fixed volume of at least the reactor processing chamber 110; 2. by adding additional gas molecules to a fixed space in at least the reactor processing chamber 110; 3. by reducing the total space of the reactor processing chamber 110 and the piston chamber space 114 ("piston-type" pressurization); 4. by increasing the pressure in at least the reactor processing chamber 110 by pumping gas through / from the pump purging and pressurizing gas 116 using a pressurizing / exhausting pump 118.

[0040] Methods for supplying dopant to the interior space 110 of the whole reactor processing chamber may include an operating gas control panel 140 and a cleanroom gas supply facility 158. While gaseous dopant delivery is shown in Figure 1A, liquid dopant may also be delivered to the interior space 110 of the whole reactor processing chamber. This can be achieved at least by bubbling a carrier gas such as N2, Ar, etc. (non-reactive gases), and may also include using a reactive carrier gas such as O2 to carry liquid dopant such as POCl3. A typical gas control panel may include multiple sets of MFC iso valves-output 146, MFC (mass flow controller) 148, MFC iso valves-input 150, gas regulators 152, and particulate filters 154. Each "route" consisting of these components may be equipped with dopant gas from dopant 1 cylinder 156 and dopant 2 cylinder 157, respectively; the cylinders may be stored in the cleanroom gas supply facility 158. Additional settings 132 for supplying gases 3 and 4 may also be connected to the dopant gas mixing block 142. If desired, liquid dopants and solid dopants (e.g., powders heated to release dopant metals, which can then be "carried" by an inert carrier gas) may also be provided to the dopant gas mixing block 142. These dopants are ultimately carried into the interior space 110 of the whole reactor processing chamber by the dopant processing gas / mist inlet 108.

[0041] For the examples of materials used in the process mentioned in this specification, the doping process can be performed as follows. A substrate / wafer 105 is loaded onto a paddle 106, and then both are moved together and loaded into the internal space 110 of the reaction chamber 102 and the full reactor processing chamber. The substrate / wafer 105 already has an MLG interconnect layer patterned as needed by photolithography. The MLG is etched to expose the MLG sidewalls for intercalation doping. For example, dopant gases such as PH3 and O2 are used to fill the internal space 110 of the full reactor processing chamber, and the temperature of the full reactor processing chamber is equilibrated at, for example, about 400°C. The pressure can then be brought to an appropriate level for the interconnect dimensions of the MLG on the substrate / wafer 105. The pressure in the internal space 110 of the full reactor processing chamber can typically be maintained for 10-60 minutes, or even longer. This is also based on engineering management calculations and considerations to dope MLG lines of various geometries into the desired thin-film resistors. After the pressure is reduced and the residual dopants and reaction gases in the tube are removed, the blade 106 can be safely removed from the reaction chamber 102, and then the substrate / wafer 105 can be removed for further processing.

[0042] [Large area] [ / ] [Wafer Level Low Temperature] [ / BEOL] [Compatible highly scalable doping tools] [second] [Example: Batch] [ / ] [single shot; adulterant] [=] [solid that vaporizes into a gas] [ / ] [Liquid; Pressurized Substrate] [=] [gas pressurization]

[0043] FIG. 1B and the embodiments shown therein have the same features of the embodiments shown in FIG. For example, doping of graphene / MLG can be described, for example, by doping of solid / liquid (vaporized to gas phase) phases with gas pressure and temperature acceleration, particularly, but not limited to, intercalation doping of MLG. This process and equipment is not limited to intercalation doping of MLG, but many other materials can be mixed using other methods through the equipment.

[0044] As shown in Figure 1B , the batch (and of course, a single substrate / wafer) treatment device 101 may include, but not limited to, at least: reaction chamber 102 (within the dashed line segment), reaction chamber doors and seals 104, substrate / wafer 105, propeller blades 106, dopant-treated gas / mist inlet 108, full reactor treatment chamber internal space 110, multi-directional high pressure valve 112, piston chamber space 114, pump sweep and pressurized gas 116, pressurization / exhaust pump 118, piston motion shaft 120, piston chamber 122, solenoid or screw motor 124, piston 126, chamber sidewall heater 130, temperature control of solid doping source 131, gas 3 and 4 additional setup 132 (optional), pump-to-chamber valve 134, solid doping source to chamber valve 135, gas control panel 140, dopant gas mixing block 142, MFC-iso valve-output 146, MFC (mass flow controller) 148, MFC-iso valve-input 150, gas regulator, pellet regulator Gas cylinder 156, dopant 2 gas cylinder 157, dust-free chamber gas supply facility 158, solid-doped source crucible 160 and solid / slurry / liquid-doped source material 162 .

[0045] The reaction chamber 102 may include a steel-encased pressure vessel capable of withstanding applied pressure and temperature, and a tubular liner that may use a material such as high-quality, high-purity quartz. The reaction chamber 102 may include several openings, such as a reaction chamber door and seal 104, a dopant treatment gas / mist inlet 108 (which may be integrated with a high-pressure shut-off valve), and an opening via a multi-way high-pressure valve 112 connecting to a pressurization device (and a pre-configured setup for supplying solid / slurry / liquid dopant source material 162 to the chamber valve 135 via a solid dopant source). The reaction chamber door and seal 104 may be opened during feeding (after the reaction chamber 102 has been vented of toxic / reactive gases and reached atmospheric pressure). The substrate / wafer 105 may be loaded onto a paddle 106. The paddle 106 may include slotted quartz "boats" (not shown) to hold the substrate / wafer 105 in a desired position—typically maintaining parallel alignment with each other at a spacing determined through engineering calculations and considerations to meet uniformity requirements.

[0046] However, there are several alternatives to how the substrate and wafer are held and processed. In the embodiment shown in Figure 1B, the batch processing apparatus 100 is drawn in a horizontal configuration. As an alternative embodiment, the batch processing apparatus 100 can also be rotated 90 degrees in the z-direction and converted into a vertical high-pressure processing chamber. The reaction chamber 102 may include a system (not shown) for mixing the input gas (possibly a dopant gas mixing block 142) and / or for providing movement and exhaust of the processing gas during operation (and movement and exhaust of the purge gas during idle periods or when the door is open). This system may be configured at the opposite end to the gas inlet location. Due to engineering and chemical considerations and selections, the dopant processing gas / mist inlet 108 may also have several alternative configurations, such as nozzles, quartz injectors, heating or cooling gas conduits, etc.

[0047] The propeller 106, reaction chamber door and seal 104, and substrate / wafer 105 can be moved together into reaction chamber 102 until the reaction chamber door and seal 104 are closed and sealed. Manual and / or automatic latches, locking teeth, etc. (not shown) can be used to provide a sufficiently strong mechanical seal for the reaction chamber door and seal 104 to maintain the pressure in reaction chamber 102 and ensure operational safety. The movement of propeller 106 and the loading of substrate / wafer 105 onto the quartz boat, and then onto propeller 106, can be performed by a robotic arm (not shown) to at least minimize defect generation (e.g., quartz dust) and human labor requirements. At this point, substrate / wafer 105 is completely located within reaction chamber 102. The temperature of substrate / wafer 105 should at least be brought to equilibrium.

[0048] Next, a composition of dopant gas and / or single or multiple types of gaseous mixtures suitable for the doped substrate / wafer 105 is introduced into the reaction chamber 102 via different MFCs. Note that these gases may be preheated, or at approximately room temperature (to provide at least part of the required pressurization from a fixed volume of heated gas), and may also be under high pressure, or the internal volume of the reaction chamber 102 may be placed under partial or full desired high pressure in the entire reactor processing chamber 110. Pressure regulation can be performed by moving the multi-directional high-pressure valve 112 to the desired position and utilizing the pressurization / exhaust pump 118 (providing pressurized gas via pump purging and pressurization gas 116) and opening the pump to the chamber valve 134. Alternatively, or in combination, the pressure in at least the entire internal space 110 of the reactor processing chamber can be regulated by changing the volume by moving the piston 126 along the piston movement axis 120 using a solenoid or screw motor 124 (for a given T, decreasing V will increase P).

[0049] The doping gas pressure within the interior space 110 of the full reactor processing chamber accelerates dopant atoms, which, combined with doping sources supplied from solid or liquid sources and in contact with the top structure of the substrate / wafer 105, increases the likelihood of implantation onto the surfaces and sidewalls of structures (e.g., interconnects) on the substrate / wafer 105. For example, doped SOGs (P-SOG, B-SOG, BP-SOG, etc.) can be applied to the substrate / wafer 105 before temperature and pressure acceleration using processing equipment 101. Alternatively, a saturated or approximately desired dopant atom layer can be deposited on the substrate / wafer 105 before processing it in processing equipment 101. Similarly, the step of forming a doped layer covering at least the substrate / wafer 105 can also be part of a process within the processing apparatus 101; in practice, for example, a carrier gas can be bubbled through POCl3 plus O2 gas running in the reaction chamber 102 to form deposited phosphorus-doped glass (PSG) on the substrate / wafer 105 and on the inner surface of the reaction chamber 102. Alternatively, a solid dopant, such as arsenic or FeCl3 powder, or a slurry, can be placed as a solid / slurry / liquid dopant source material 162 in a solid dopant source crucible 160, and then appropriately heated to degas by controlling the temperature of the solid dopant source 131, thereby providing a gaseous doping method accelerated by temperature and pressure. An alternative method is to place the solid / slurry / liquid dopant source material 162 within the reaction chamber 102, but this would prevent individual temperature control of the solid / slurry / liquid dopant source material 162. It is worth noting that a significant pressure increase can be achieved simply by heating the gas within a fixed volume of the sealed / isolated reaction chamber 102.

[0050] The dopant atoms colliding with the surface of the substrate / wafer 105 can be accelerated by increasing the temperature of the substrate / wafer 105 and the dopant gas, thereby increasing the solid-state diffusion rate through a portion of the substrate / wafer 105. One method of heating involves applying the dopant process gas / mist inlet 108 into the interior space 110 of the entire reactor process chamber, which is heated by at least the chamber sidewall heaters 130. However, it should be noted that the dopant gas may be preheated or cooled before being injected into the interior space 110 of the entire reactor process chamber through the dopant process gas / mist inlet 108, if deemed necessary by engineering management and chemical calculations and considerations. The temperature range of the interior space 110 of the entire reactor process chamber, and the temperature range of at least the substrate / wafer 105 when the temperature reaches equilibrium, can be from about 25°C to about 500°C, with a uniformity of less than ±5°C. The interior space 110 of the entire reactor process chamber can be designed to accommodate substrates / wafers 105 with a diameter of at least 450 mm (if circular wafers). Alternatively, if the substrate is square / rectangular, it should be able to accommodate a substrate / wafer 105 with a side length of 450 mm. The tooling processing unit 101 can also be modified to accommodate substrates in continuous form. The pressure range of the internal space 110 of the full reactor processing chamber can be approximately 20 psi, approximately 30 psi, approximately 40 psi, approximately 50 psi, approximately 60 psi, approximately 70 psi, approximately 80 psi, approximately 90 psi, approximately 100 psi, approximately 110 psi, approximately 120 psi, approximately 130 psi, approximately 150 psi, approximately 200 psi, approximately 250 psi, approximately 300 psi, approximately 350 psi, approximately 400 psi, approximately 450 psi, and may exceed approximately 500 psi, or 1-500 bar, depending on engineering management and design objectives, selections, and considerations.

[0051] A method for supplying gaseous and material dopants that can form solid / liquid (glass can be considered a viscous liquid) dopants to the interior space 110 of the total reactor processing chamber may include an operating gas control panel 140 and a cleanroom gas supply facility 158. Although gaseous dopant delivery is shown in Figure 1B, liquid dopants may also be delivered to the interior space 110 of the total reactor processing chamber. This may be done at least by bubbling a carrier gas such as N2, Ar, etc. (non-reactive gases), and may also include using a reactive carrier gas such as O2 to carry liquid dopants such as POCl3. A typical gas control panel may include multiple sets of MFC iso valve-output 146, MFC (mass flow controller) 148, MFC iso valve-in 150, gas regulator 152, and particulate filter 154. Each "route" consisting of these components may be equipped with dopant gas from dopant 1 gas cylinder 156 and dopant 2 gas cylinder 157, respectively; the gas cylinders may be stored in the cleanroom gas supply facility 158. Additional settings 132 for gases 3 and 4 can also be connected to the dopant gas mixing block 142. If desired, liquid dopant as well as solid dopant (e.g., powder heated to release dopant metal, which can then be "carried" by an inert carrier gas) can be supplied to the dopant gas mixing block 142. These dopants are ultimately carried into the interior space 110 of the entire reactor processing chamber by the dopant processing gas / mist inlet 108.

[0052] For the examples of materials used in the process mentioned in this specification, MLG can be formed first, and then the intercalation doping process can be performed as follows: A substrate / wafer 105 is loaded onto a paddle 106, and then both are moved together and loaded into the internal space 110 of the reaction chamber 102 and the full reactor processing chamber. The substrate / wafer 105 already has an MLG interconnect layer patterned as needed by photolithography. The MLG is etched to expose the MLG sidewalls for intercalation doping. For example, dopant gases such as PH3 and O2 are used to fill the internal space 110 of the full reactor processing chamber, and the temperature of the reactor processing chamber is equilibrated at, for example, about 400 °C. Simultaneously, the pressure can be made appropriate for the interconnect dimensions of the MLG on the substrate / wafer 105. (See the description of "at least four ways" of increasing pressure in the preceding paragraphs of this document.) The pressure in the internal space 110 of the full reactor processing chamber can typically be maintained for 10-60 minutes, or even longer. This is also based on engineering management calculations and considerations to dope MLG lines of various geometries into the desired thin-film resistors. Afterwards, the pressure is reduced and residual dopant and reactive gases in the tube are removed, and then the paddle 106 can be safely removed from the reaction chamber 102. After that, the substrate / wafer 105 can be removed for further processing.

[0053] [Large area] [ / ] [Wafer-level low temperature] [BEOL] [Third embodiment of a compatible, highly scalable doped tool: pressure plate] [ – ] [Single Film] [ / ] [Multiple wafers; dopant] [ = ] [A solid that vaporizes into a gas] [ / ] [Liquid; Substrate pressurization] [ = ] [Gas pressurization]

[0054] Figure 2 shows a schematic diagram of an exemplary embodiment of a non-contact pressurization system that uses solid / liquid dopants (vaporized into gas) and horizontal monolithic or multi-wafer / substrate pressure plates to generate gas pressure in a piston-like manner. The piston-like gas pressure generation system 200 of this embodiment may include, but is not limited to, a substrate / wafer 202, a slit 206, a processing chamber space 204, a bottom heating plate 208, a valve 207, a piston 218, a minimum space processing chamber 210, a solenoid or screw motor 212, a piston space 214, a piston movement shaft 220, a chamber sidewall heater 230, a temperature controller 231 for the solid dopant source, a valve 235 from the solid dopant source to the chamber, a solid dopant source crucible 260, and a solid dopant source material 262. The piston-like gas pressure generation system 200 of this embodiment may also include a gas supply system, shown in Figure 2B above the center of Figure 2A. This figure is taken from Figure 1B, and therefore the gas supply system can be similar to the gas supply system of Figure 1B.

[0055] The piston-type pneumatic generation system 200 of this embodiment utilizes a combination of gas laws to allow machine operators to manipulate volume and temperature conditions via software control devices. This alters the pressure applied to the top surface of the substrate / wafer 202, accelerating the diffusion of dopant atoms or molecules through the material to be doped. This material can be, for example, graphene, such as single-layer or few-layer graphene structures, or multilayer graphene (MLG) structures. The graphene layer to be doped can be located on the sidewalls of graphene lines or thin strips, primarily through intercalation doping to provide more efficient and higher-quality doping.

[0056] As will be described in more detail below, the substrate / wafer 202 can enter the minimum space processing chamber 210 via slit 206 and be placed on top of the bottom heating plate 208. Heating control of the wafer and gas can be performed via at least the bottom heating plate 208 and various chamber sidewall heaters 230, the actual method of which can be determined through engineering management choices and considerations / trades. Alternative methods for heating the gas and wafer may include, for example, heating lamps. The bottom heating plate 208 may include a rotation function to allow for improved temperature uniformity in the heat treatment, which may include doping processes, interconnect agent application, and some thin film formation processes. The aforementioned rotation function of the bottom heating plate 208 can be combined with most non-contact pressure functions to provide diffusion acceleration for diffusion pairs and doping processes such as intercalation doping. In this application, processing chamber and reaction chamber may refer to the same concept.

[0057] Figure 2 illustrates the pressure applied to the surface above the substrate / wafer 202 controlled by a piston system (and the increased pressure as the gas heats up in a fixed volume). Both the processing chamber space 204 and the piston space 214 can be changed from their initial space (204 + 214) to a final space (204 + 214 minus the space where the piston 218 is inserted) by using a solenoid or screw motor 212 to move the piston 218 along the piston movement axis 220. This changes the overall volume, but because the dimensions of the container walls do not increase, the pressure in the processing chamber space 204 and the piston space 214 can be increased.

[0058] The operation of another embodiment of the processing chamber 210 is described below. A clean and dry substrate / wafer 202 is placed on a bottom heating plate 208 through a slit 206. A small vacuum pump (not shown) can be used to bring the processing chamber 204 to 100-300 mTorr, and the wafer 202 can be heated to approximately 200 °C using the bottom heating plate 208 to dry the wafer. The vacuum pump (not shown) can also be used to hold the wafer / substrate 202 securely on the bottom heating plate 208 and can be used to assist in the substrate / wafer 202 dehydration process. The substrate / wafer 202 may then have a dopant layer already deposited thereon, or it can be doped using a piston-type gas pressure generation system 200 configured for depositing a doped layer, for example, forming SiO2 doped with POCl3. The above process has been described in detail at least in the description of FIG. 1B in this specification. In this stage, in addition to temperature, gas pressure can be used to accelerate the movement of dopant atoms from the doped layer of wafer 202 through the material to be doped (e.g., single-crystal silicon or MLG). The time the system is at this temperature and the applied gas pressure can be controlled to produce the desired dopant movement. At least as described in this specification with reference to FIG1A, the dopant supplied to the surface of substrate / wafer 202 can originate from gas injected into reaction chamber 210 (not shown in FIG2, but shown in FIG1). The possibility of dopant atoms entering the surface of substrate / wafer 202 and, as needed, being injected and diffused into the top structure, top structure region, or layer of wafer / substrate 202 can be increased by pressurizing these gases and / or pressurizing the reaction chamber. It should be noted that the bottom heating plate 208 can be configured with a multi-wafer / substrate holder, such as a wafer platen, to process more than one wafer simultaneously, thereby increasing tooling productivity (see exploded schematic diagram of the right-hand top view of FIG2).

[0059] Furthermore, another embodiment of the invention includes orienting the pressurized cylinder piston space 214 and the moving piston 218 vertically, rather than in the horizontal configuration shown in the embodiment of FIG2. Additionally, the pressurized cylinder piston space 214 and the moving piston 218 can be placed directly above each wafer / substrate 202 and the bottom heating plate 208, similar to, for example, a large internal combustion engine cylinder in a 6-cylinder automobile engine. FIG2A shows a schematic diagram of an example embodiment of a non-contact pressurization system with the above-described vertical orientation configuration. This system utilizes a piston cylinder above the substrate / wafer to generate gas pressure containing gaseous / solid / liquid dopants and uses pressure plates for holding single or multiple wafers / substrates. FIG2A shows a portion of the overall tooling. The embodiment of FIG2A may also include various embodiments of both FIG2 and FIG1B.

[0060] The piston-cylinder type pneumatic generation system 299 of this invention may include, but is not limited to: a substrate / wafer 202, a slit 206 (see FIG. 2), a processing chamber / reactor internal space 204, a bottom heating plate 208, a valve 207 (see FIG. 2), a piston 266, a solenoid or screw motor 268, a shaft 264 from the piston 266 to the motor 268, a piston movement direction 270, a processing chamber sidewall 262, a processing chamber sidewall heater 230 (see FIG. 2), a shaft 280 of the heating base 208, a support structure 278 for the bottom heating plate 208, solid vaporization structures 235, 231, 260, 262 (see FIG. 2), a main substrate / wafer 272, a dopant layer 276 (optional), an exemplary structure to be doped 274 (or the substrate to be processed, such as glass), and a substrate (typically silicon) 272. As previously described, the piston-cylinder type gas pressure generating system 299 of this embodiment may also include a gas supply system, shown in Figure 2B, which is taken from Figure 1B, at the top center of Figure 2A. Therefore, this gas supply system may be similar to the gas supply system in Figure 1B. Similarly, the pump and solid / slurry / liquid dopant source are also shown in the shaded area at the bottom left. This figure is taken from Figure 1B, so this part may also be similar to the corresponding part in Figure 1B.

[0061] Optional dopant layer 276 (if configured for solid / liquid doping) can be deposited to form a highly doped layer as a dopant source. For example, it can be formed in a diffusion tube (e.g., POCl3) via doping CVD or PECVD processes. Alternatively, optional dopant layer 276 can be formed by depositing a thin oxide layer and treating the oxide via a PLAD process or conventional ion implantation. Furthermore, optional dopant layer 276 can also comprise a spin-coated layer of doped glass (d-SOG) or other organic material, which can be baked and degassed before pressure is applied, or can remain "soft" without baking. The structure 274 to be doped in this embodiment can include an MLG interconnect structure implemented after etching and cleaning, such that the MLG edges are exposed to the optional dopant layer 276, or the exposed structure is exposed to the interior space 204 of the processing chamber / reactor. Note that Figure 2A only shows the processing reactor / chamber portion of the tool / apparatus and can be combined with certain portions of Figure 2 to show a substantially complete high-order schematic of the tool.

[0062] A typical process for the tool formed in conjunction with Figure 2A may include the following steps: First, the substrate / wafer 202 may be placed / loaded onto the bottom heating plate 208 through the slit 206, with the pin (not shown) of the heating plate 208 facing upwards. The pin is then retracted, so that the main substrate / wafer 272 on the back side of the substrate / wafer 202 is firmly in contact with the bottom heating plate 208. At least the processing chamber sidewalls 262 and piston 266 are retracted upwards in this step to avoid obstructing the loading of the substrate / wafer 202. At this time, at least the two sidewalls 262 of the processing chamber are moved downwards to contact the bottom heating plate 208, sealing the space. (However, if a pressure chamber has already been used to surround most of the piston-cylinder pneumatic generation system 299 of this embodiment, this sealing step is no longer important.) During the doping layer deposition step, a gap may be left between the processing chamber sidewalls 262 and the bottom heating plate 208. The internal space 204 of the processing chamber / reactor may then be purged and emptied. This step may be repeated if necessary based on engineering management data and selection. The substrate / wafer 202 can be brought to the desired temperature using the bottom heating plate 208 and the chamber sidewall heaters 230. A solenoid or screw motor 268, driven by a piston 26 and a shaft 264 to the motor 268, can be used to compress the volume of the processing chamber / reactor interior space 204, thereby increasing the gas pressure within the processing chamber / reactor interior space 204. This increases the pressure applied to the upper surface of the optional dopant layer 276 or the upper surface of the exemplary structure 274 to be doped, for direct gaseous doping. The position of the piston 266 can be adjusted to obtain the desired pressure in the processing chamber / reactor interior space 204 and on the upper surface of the exemplary structure 274 to be doped or the optional dopant layer 276. The pressure can also be maintained or regulated by changing the applied pressure. The pressure can also be regulated by vibrating or moving the piston 266 to achieve the required pressure (and temperature) acceleration for doping the exemplary structure 274 to be doped.

[0063] [Large area] [ / ] [Wafer-level low temperature] [BEOL] [Fourth embodiment of a compatible, highly scalable doped tool: a pressure plate] [ – ] [Single Film] [ / ] [Multiple wafers; dopant] [=] [gas] [ / ] [solid] [ / ] [Liquid, vaporized, or not vaporized into gas; substrate pressurized] [=] [Direct contact mechanical type]

[0064] Figure 3 shows a schematic diagram of a batch (and of course, can also be used to operate a single wafer / substrate in an apparatus) doping apparatus and an example process of an embodiment of the present invention. In this embodiment, gas is introduced into processing chamber 310 to dope the substrate / wafer 202 of the embodiment, and mechanical pressure and temperature are used to accelerate the doping process. The mechanical pressure generated in the tool / apparatus 300 of this embodiment is a direct-contact type of mechanical pressure. The substrate / wafer 202 used can include a variety of materials in various configurations for doping. However, the example used in this embodiment is a substrate / wafer 202 formed as a single-crystal silicon wafer with a formed thick oxide structure having openings etched into the silicon layer. In-situ doping tool / apparatus 300 may include, but is not limited to: a top heating plate 340, a bottom heating plate 208, a processing or reaction chamber 310, a substrate / wafer 202 including a silicon substrate having an oxide structure on the top layer, a drive motor 302, a mechanical / turbine pump 304, a shaft 305 from the motor 302 to the top heating plate 340, a control valve 306, an exhaust device 308, a purging device 311, a bottom heating power supply 350, a shaft 354 from the bottom heating power supply 350 to the bottom heating plate 208, a gas nozzle 312, a dopant gas mixing block 314, an MFC ISO valve-output 316, and an MFC (mass flow controller) 318. ISO valve-input 320, gas regulator 322, particulate filter 324, dopant 1 gas cylinder 326, dopant 2 gas cylinder 327, cleanroom gas supply facility 328, gas control panel 330, and additional settings 332 for gases 3 and 4 (if needed). The apparatus and process of this embodiment include introducing a carrier gas containing dopant into a chamber at a suitable pressure to allow the dopant to diffuse / migrate into a silicon material having an oxide structure. The above process can be performed directly in the processing chamber of the present invention having a top heating plate and a bottom heating plate; or in the processing apparatus of other embodiments described in this specification. If plasma is required to enhance the process, electrodes can be provided in each heating plate to achieve this. However, the use of a remote / downstream plasma source is also conceivable. This aforementioned application method can also be used in other chamber embodiments described in this application (e.g., pressurized batch chambers, including at least the embodiment shown in Figure 1 of this specification).

[0065] Dopant can be inserted into the topmost monocrystalline silicon surface, for example, through physical contact with a solid dopant material (as is commonly done in industry using boron disks to contact Si for boron doping). In this invention, after a wafer with a monocrystalline silicon and oxide structure is placed, a solid dopant disk (functionally similar to the aforementioned optional dopant layer 276) can be placed into a chamber, for example, with top and bottom heaters. The solid dopant disk can be placed on top of the wafer with the monocrystalline silicon and oxide structure. Then, the top heating disk is first gently moved, and the pressure is gradually increased until the desired pressure is reached to push the dopant disk against the front (top) surface of the substrate / wafer 202. The pressure level should be set at a value that optimizes dopant diffusion. Heating with heaters and applying an electric field (neither shown) can be used as needed to facilitate the process. As shown at least in Figure 2A and the related description section, if a liquid or solid type of dopant source is desired, the substrate / wafer 202 may include at least a dopant layer 276 (optional), an exemplary structure 274 to be doped (or a portion of the substrate to be doped, such as glass, etc.) and the substrate 272 itself (typically silicon).

[0066] Pressure on the substrate / wafer 202 can be mechanically applied by pressing a top heating pad 340 down onto the top of a solid dopant pad. This solid dopant pad is located on top of the structure to be doped, such as the MLG interconnect structure in other embodiments of this specification, and the single-crystal silicon and oxide structure in this embodiment, thereby forcing the dopant into the single-crystal silicon and oxide structure and regions of the device. High temperatures, as described above, can also be applied to aid in induction, completing the doping in the desired single-crystal silicon and oxide structure and regions. Using this process may require rigorous surface cleaning and may result in a higher defect rate than in other doping processes of the present invention. The solid dopant pad may comprise a relatively soft layer of doped material, such as PECVD BPSG or PSG, or a doped SOG (spin-coated glass) layer. These materials are soft enough to be forced into the spaces between exposed interconnects on the substrate / wafer 202 by pressure applied, for example, by the top heating pad 340. These interconnects contain, for example, molecular alignment materials (e.g., MLG). Therefore, the applied pressure can induce a considerable degree of intercalation doping into / through the sidewalls of the MLG interconnect.

[0067] [Exemplary Example]

[0068] The following describes the configuration of a reactor used to apply other forms of heat and / or pressure to a substrate. It should be noted that the above configuration is only one of many available configurations. Alternative configurations of the present invention may include, but are not limited to: - Subjecting the heated film to high pressure (e.g., pneumatic or hydraulic pressure); - Available in clamshell configurations for high-temperature and high-pressure heating of N2, Ar, or other similar gases; - Large-scale reactors with the same characteristics as described above; - A clamshell configuration, but using a combination of methods for pressurizing and heating the substrate as described above. For example, high-temperature, high-pressure gas can be introduced; high pressure can be introduced, and the substrate can be heated by a bottom heater, while the high-temperature gas is heated by a bottom heater, simultaneously performing the pressurization function and maintaining the temperature, etc. - A quartz body with a support plate placed on a base, using high-pressure gas for induction heating and pressure loading; and - It can also include configuring an array of lamps in the quartz body for final temperature control.

[0069] The following description demonstrates several operating ranges of the system of the present invention, as well as the range of parameters such as material structure and composition required to obtain optimal process results.

[0070] It should be noted that the reaction apparatus can be implemented as a batch reactor and / or a single-substrate (wafer) reactor. It is worth noting that using a single-substrate configuration allows for finer substrate-to-substrate process control compared to batch reactors. Batch processing can also be achieved using only a single-wafer architecture by placing a stack of wafers between two heaters.

[0071] [Alternating Doping Method]

[0072] Another embodiment of the device system of the present invention can also be used to introduce dopants into wafers, as well as into structures on / within wafers. This is because the chamber infrastructure allows for such operations. At least six methods for material carrier doping are listed in the literature: 1) boron or nitrogen substitution doping; 2) deposition of alkali metal atoms; 3) adsorption of gases such as NO2; 4) charge transfer of conjugated organic molecules; 5) liquid-phase interaction between graphene and dopant molecules; 6) spin-coating, for example, a mixture of TCNQ and PMMA. References for the doping methods listed above can include at least Hans He et al.: “Uniform doping of graphene close to the Dirac point by polymer-assisted assembly of molecular dopants”, Nature Communications, September 27, 2018, pp. 1–7; and V. Narendar et al.: “First Principle Study of Doped Graphene for FET Applications”, Silicon v, Vol. 11, pp. 277–286 (2019). R. Ishikawa et al., “Doping graphene films via chemically mediated charge transfer,” Nanoscale Research Letters, Vol. 6, pp. 111-116 (2011). All of the above is incorporated herein by reference. For a description of intercalation doping techniques, see at least W. Liu, J. Kang, and K. Banerjee, “Characterization of FeCl3 Intercalation Doped CVD Few-Layer Graphene,” IEEE Electron Device Letters, Vol. 37, No. 9, pp. 1246-1249, September 2016; and J. Jiang, JH Chu, and K. Banerjee, “CMOS-compatible doped-multilayer-graphene interconnects for next-generation VLSI,” IEEE IEDM, 2018, pp. 34.5.1-34.5.4. All of the above is incorporated herein by reference. However, much of what it contains may be impractical for certain types of doping, such as charge transfer through surface adsorption doping.

[0073] Intercalation doping applications typically require access to the "edges" of layered structures because doping directly through the tight matrix of layered atoms is very difficult. Therefore, layered materials such as graphene / MLG can be used to perform the desired photolithography and etching processes for that particular interconnect layer. The wafer can then be cleaned in a separate machine or within the processing chamber of the apparatus described in this invention, and a dopant source layer can be deposited. The dopant can then be driven into the exposed MLG sidewalls using the heating and pressurizing capabilities of the apparatus disclosed in this invention. The wafer can then be removed from the processing chamber, and the dopant layer can be selectively removed. In some applications, the dopant layer can also be left on the wafer as a capping layer to prevent dopant diffusion outwards from the MLG lines.

[0074] The apparatus described at least in Figures 1 through 3 may further include a transfer chamber for loading substrates / wafers into a reactor / processing chamber, and may be used to pre-treat the substrates / wafers before they move from the transfer chamber to the reactor / processing chamber. Pre-treatment of the substrates / wafers may include rotational and / or translational movements of the wafers to fix the alignment of, for example, a “notch” or “plane” or some other substrate (wafer) crystal orientation indicator, to place the wafers in a constant or variable alignment position before transfer to the reactor / processing chamber. Wafer pre-treatment may also include heating the wafers to dry moisture and / or preparing the wafers to a temperature that can shorten heating time or improve the processing performed in the reactor / processing chamber. Wafer pre-treatment may also include purging the transfer chamber with an inert gas (e.g., N2, Ar, He, etc.); or purging the transfer chamber with a reactive gas, such as O2, O3, etc. Wafer pretreatment may also include various exposures to the electromagnetic spectrum, such as UV, X-rays, and IR, to activate or push specific atoms into excited states, for example, RTA (rapid thermal annealing) or RTO (rapid thermal oxidation). Furthermore, wafer pretreatment may also include plasma exposure to the wafer, for example, to clean the wafer surface or to chemically activate portions of the wafer surface in preparation for other processes (e.g., growing oxides, deactivating the wafer surface, etc.).

[0075] Various combinations and sub-combinations of at least the preprocessing options described above can be performed to, for example, create a preprocessing procedure. Examples include heating the wafer, exposing the wafer to UV light and subjecting it to an O2 or O3 purging / atmosphere (and possibly an oxidizing or reducing atmosphere, particularly for wafer cleaning) to form a thin oxide layer on some or all of the wafer's surface, and so on.

[0076] The term "substrate / wafer" as used herein can include various sizes (e.g., diameters of approximately 450 mm, 400 mm, 300 mm, 200 mm, 150 mm, etc.). When viewed from above, the substrate / wafer can include other overall shapes (ignoring notches, planes, etc.), such as circular, square, rectangular, etc. The substrate / wafer composition can include, for example, materials containing crystalline substances, such as elemental silicon, germanium, aluminum, copper alloy SiGe, aluminum, h-BN, various glasses (amorphous or crystalline), amorphous forms of Si, Ge, etc. The substrate / wafer composition can also include, for example, composite materials, such as SOI (silicon-on-insulator), GeOI, etc. The wafer / substrate can be placed into the transfer chamber by an operator / user / robot. The machine can be configured to perform this loading in an automated manner, including using wafer containers, such as FOUPs, etc.

[0077] The reactor / processing chamber and the transfer chamber can be connected via a slit structure. The machine control software can be configured to automatically open the slit once the pressure inside the two chambers is equalized. The equipment may include a hardwired backup control system with redundant pressure sensors to ensure that wafers are transferred only when the pressure between the reactor / processing chamber and the transfer chamber is equal, for safety reasons.

[0078] In addition to accelerating dopant diffusion, this reactor / processing chamber can also serve as the main reaction chamber (or reactor) for growing or depositing various material layers (e.g., doped layers) on wafers. However, due to contamination and particle issues, the growth of many materials, such as graphene (and / or other carbon materials), requires dedicated processing chambers. The reactor / processing chamber can be configured to accommodate substrates slightly larger than 450 mm. The reactor / processing chamber can be equipped with a heater system to heat the inner walls, thereby not only meeting processing requirements but also making cleaning and maintenance easier or less frequent. Depending on process details, the gases used, and other engineering considerations, the inner walls of the reactor / processing chamber can also include a cooling system to suppress bypass deposition of process reaction gases, thereby achieving longer chamber cleaning and maintenance cycles and reducing film defects caused by particles deposited on the inner walls falling onto the wafer or being blown onto the wafer by process gas flow during in-situ processes.

[0079] A top heating plate or heating disk (e.g., see top heating disk 340) can also be installed in the reactor / processing chamber. The top heating disk 340 and / or the bottom heating disk 208 can each be equipped with their own heating mechanism (e.g., heating power supply 350 shown for the bottom heating disk 208). In this way, the wafer-placed tray and the heated top disk can be heated independently and their temperatures controlled separately by machine software. For example, the top can be kept at approximately room temperature (or vice versa) while the tray is heated. The top heating disk and / or the bottom heating disk can be configured to include multiple independently controllable areas located on the disk. For example, concentric rings with different temperature controls, or temperature-controlled zones like those for slicing a pizza. Combinations of the above can also be configured.

[0080] The substrate surface (used to cover the heating plates, such as the top heating plate 340 and / or the bottom heating plate 208, and to cover the inner wall of the reactor / processing chamber 310) can be made of graphite, but can also be made of other materials such as aluminum nitride, quartz, silicon carbide, etc. Coated graphite, etc., can be used. Several such materials can also be used—generally, materials that allow for good heat transfer and pressure distribution can be considered. Particle formation can also be affected by surface finish, adhesion of the deposited film, coefficient of thermal expansion, etc. The reactor / processing chamber 310 and other chambers described in this specification can include, for example, the ability to ignite plasma using NF3 and Ar to provide in-situ internal chamber surface cleaning procedures to help minimize the risk of wafer surface contamination or the formation of embedded thin film defects, thereby extending chamber maintenance cycles.

[0081] Mechanical / turbine pump 304 can be used to control the pressure in reactor / processing chamber 310 and / or transfer chamber (not shown). The mechanical pump can be used to reduce the pressure in the reactor / processing chamber (e.g., to 10⁻³ Torr). The turbine pump can be a more powerful pump for further pressure reduction (e.g., 10⁻⁷ Torr). Low pressure is required during some operating cycles to purge any impurities from the chamber.

[0082] The temperature on the bottom heating plate 208 can be heated and controlled using the heating power supply 350. Heating and temperature control can be achieved through the ±5°C uniformity (and / or near-zero non-uniformity) of the bottom heating plate 208. The top heating plate 340 and the bottom heating plate 208 may each include multiple thermocouples embedded in each heating plate or temperature sensing devices inserted therebetween to provide temperature input values ​​to the temperature control system (e.g., a proportional feedback control system). The bottom heating plate 208 can generate heat using a current resistor from the heating power supply 212, or it can be heated by water to a certain temperature range (not shown), or it can be heated by a light source (not shown) placed inside the reactor / processing chamber 310, to simultaneously at least assist the bottom heating plate 208.

[0083] The top heating plate 340 can move up and down along an axis 352 perpendicular to the bottom surface of the top heating plate 340 and the top surface of the bottom heating plate 208. The top heating plate 340 can have an independent heating source. The top heating plate 340 is operable to generate mechanical pressure above the substrate / wafer. For example, pressure can be achieved using a shaft 305, a motor, screw telescopic motion, etc. In addition to mechanical pressure, gas pressure can also be used. Alternatively, gas pressure can be used instead of mechanical pressure. The purpose of applying pressure is to generate a higher dopant diffusion rate in the doped top layer of the substrate / wafer 202, or to generate a higher dopant diffusion rate in the substrate material of the substrate / wafer 202 (e.g., single-crystal silicon, SiO2 as glass, as a network modifier, etc.).

[0084] Please see at least U.S. Patent Application No. 63 / 123,587 and PCT / US21 / 61361, and at least the following papers: J. Jiang et al., “Intercalation doped multilayer-graphene-nanoribbons for next generation interconnect”, Nano Letters, 17(3), pp. 1482-1488, 2017; J. Jiang et al., “All-carbon interconnect scheme integrating graphene wires and carbon-nanotube-vias”, IEEE IEDM, pp. 14.3.1-14.3.4, 2017. J. Jiang et al., “CMOS-Compatible Doped-Multilayer-Graphene Interconnects for Next-Generation”, VLSI, IEEE IEDM, pp. 34.5.1-34.5.4, 2018. K. Agashiwala et al., “Reliability and Performance of CMOS-Compatible Multi-Level Graphene Interconnects Incorporating Vias”, IEEE IEDM, 2020. K. Agashiwala et al., “Demonstration of CMOS-Compatible Multi-Level Graphene Interconnects with Metal Vias”, IEEE Transactions on Electron Devices, Vol. 68, No. 4, April 2021, pp. 2063-2091. All of the above are cited and incorporated in this specification.

[0085] The top heating plate 340 can be moved to provide mechanical pressure to the substrate / wafer 202 when it is positioned on the bottom heating plate 208. For example, this mechanical pressure can be approximately 20 psi, approximately 30 psi, approximately 40 psi, approximately 50 psi, approximately 60 psi, approximately 70 psi, approximately 80 psi, approximately 90 psi, approximately 100 psi, approximately 110 psi, approximately 120 psi, approximately 130 psi, approximately 150 psi, approximately 200 psi, approximately 250 psi, approximately 300 psi, approximately 350 psi, approximately 400 psi, approximately 450 psi, and can be greater than approximately 500 psi, or 1-500 bar. When the top heating plate 340 applies mechanical pressure to the top surface of the substrate / wafer 202, the pressure in the reactor / processing chamber 310 can be maintained at a low value. The pressure inside the reactor / processing chamber 310 can be, for example, 10⁻⁶ to 10⁻⁷ Torr to prevent contamination during the diffusion process. The pressure inside the reactor / processing chamber 310 can be regulated at least by means of a mechanical / turbine pump 216.

[0086] The diffusion pressure applied to the top surface of the substrate / wafer 202 can also be generated by alternative means; for example, it can be generated by using the pressure of high-pressure gas applied inside the reactor / processing chamber 310 (or another sub-chamber contained therein) within the reactor / processing chamber 310. Another alternative is to generate the gas pressure in a piston-like manner, which can produce a smaller number of particles within the reactor / processing chamber 310 and still does not require contact with the top surface of the wafer.

[0087] Please note that when the substrate / wafer 202 has a temperature below ~450°C, it is compatible with the CMOS / BEOL thermal budget. BEOL is a process step performed after the fabrication of front-end transistors to form a semiconductor integrated circuit. Once the manufacturing process has built transistors on the wafer, subsequent processing steps should be performed within a thermal budget of approximately 450°C to avoid damaging the transistors and various contacts, which could lead to short circuits and reliability issues. Not all applications of the tools described in this invention are subject to this temperature limitation. For example, doping at junctions in single-crystal silicon, dopant diffusion through spacer materials, etc., are examples in semiconductor processes where the upper temperature limit can be much higher, possibly around 650°C or 900°C. Similarly, processing using a glass substrate can be implemented, for example, in a similar tape-and-roll layout and requires temperatures above 450°C.

[0088] The pressure in the reactor / processing chamber can be calibrated and monitored using a pressure sensor, which can be placed on the steps of the base. Measurement can be achieved by monitoring the current drawn by a motor that applies pressure between the surfaces, or by using a configured flexural element, such as a strain gauge embedded in the substrate material. Similarly, temperature can be monitored using thermocouples and RTDs mounted in the base, IR sensors, phosphorus-based sensors, and laser spectroscopy sensors for chemical and / or elemental determination.

[0089] While several embodiments of the invention have been described above with reference to specific examples, various modifications and variations can be made to these embodiments without departing from the spirit and scope of the various embodiments. Therefore, this specification and drawings are illustrative in nature and not intended to limit the scope of the invention.

[0090] 100: Batch processing device 101: Batch processing device 102: Reaction Chamber 104: Reaction chamber door and seals 105: Substrate / Wafer 106: Paddle Blade 108: Dopant Processing Gas / Mist Inlet 110: Internal space of the entire reactor processing chamber 112: Multi-directional high-pressure valve 114: Piston chamber space 116: Pump purging and pressurizing gas 118: Pressurization / Exhaust Pump 120: Piston motion shaft 122: Piston Chamber 124: Solenoid or screw motor 126: Piston 130: Chamber sidewall heater 131: Temperature control of solid-state doped sources 132: Additional settings for gases 3 and 4 134: Chamber valve 135: Chamber valve 140: Gas Control Panel 142: Dopant Gas Mixing Block 146: MFC (Mass Flow Controller) ISO Valve - Output 148: MFC (Mass Flow Controller) 150: MFC ISO valve - input 152: Gas Regulator 154: Particulate Filter 156: Gas cylinder containing dopant 1 157: Gas cylinder containing dopant 2 158: Cleanroom Gas Supply Facilities 160: Solid doped source crucible 162: Solid / Slurry / Liquid Doped Source Materials 200: Piston-type pneumatic generation system 202: Substrate / Wafer 204: Processing Room Space 206: Slit 207: Valve 208: Bottom heating plate 210: Minimum Space Processing Room 212: Solenoid or screw motor 214: Piston Space 216: Mechanical / Turbine Pump 218: Piston 220: Piston motion shaft 230: Chamber sidewall heater 231: Temperature controller for solid-state doped sources 235: Valve from solid-doped source to chamber 260: Solid doped source crucible 262: Solid doped source material / processing chamber sidewall 264: Shaft of motor 268 266: Piston 268: Solenoid or screw motor 270: Piston movement direction 272: Main substrate / wafer 274: Exemplary structure to be doped 276: Dopant layer 278: Bottom heating plate 208 support structure 280: Bottom heating plate 208 shaft 299: Piston-cylinder type pneumatic generation system 302: Drive motor 304: Mechanical / Turbo Pump 305: Shaft from motor 302 to top heating plate 340 306: Control valve 308: Exhaust system 310: Processing Room 311: Purge device 312: Gas Nozzle 314: Dopant Gas Mixing Block 316: MFC ISO valve - output 318: MFC (Mass Flow Controller) 320: MFC ISO valve - input 322: Gas Regulator 324: Particulate Filter 326: Dopant Cylinder 1 327: Dopant 2 cylinders 328: Cleanroom Gas Supply Facilities 330: Gas Control Panel 332: Additional settings for gases 3 and 4 340: Top heating plate 350: Bottom heating power supply 352: Axis 354: Shaft from bottom heating power supply 350 to bottom heating plate 208

Claims

1. An intercalation doping device for inserting dopant atoms, ions, or molecules into a two-dimensional material under pressure and temperature acceleration, the device comprising: A reaction chamber, configured to receive at least one substrate, wherein a pressure in the range of 1.1 bar to 500 bar is applied to at least one surface of the at least one substrate; a heater, wherein the heater applies heat to the at least one substrate, and wherein the at least one substrate is heated to a temperature between 25°C and 500°C; and a dopant application device, wherein the dopant application device includes a valve and a conduit connecting a dopant source to the reaction chamber, and the valve controls the flow of the dopant into the reaction chamber, or includes a crucible containing the dopant and placed within the reaction chamber, wherein the dopant includes an intercalation dopant, wherein the at least one substrate includes a single or multiple layered graphene (MLG) or other layered two-dimensional material, wherein the single or multiple layered graphene or the other layered two-dimensional material includes an etched pattern, wherein the etched pattern includes an edge, wherein the edge is exposed to the dopant, and wherein the pressure is generated at least partially by introducing gas into the reaction chamber.

2. The apparatus according to claim 1, wherein, This intercalation doping reversibly inserts atoms, molecules, or ions between the layers of the layered two-dimensional material.

3. The apparatus according to claim 1, wherein, The pressure is applied in the form of gas.

4. The apparatus according to claim 1, wherein, The pressure is applied mechanically.

5. The apparatus according to claim 1, wherein, The at least one substrate comprises at least one wafer, wherein the diameter or side length of the at least one substrate is between 25 mm and 450 mm.

6. The apparatus according to claim 1, wherein, The reaction chamber is horizontally oriented.

7. The apparatus according to claim 1, wherein, The dopant application device includes at least one movable pressure piston designed not to contact the at least one substrate.

8. An intercalation doping device for inserting dopant atoms, ions, or molecules into a two-dimensional material under pressure and temperature acceleration, the device comprising: A reaction chamber, wherein the reaction chamber is configured to receive at least one substrate, wherein a pressure in the range of 1.1 bar to 500 bar is applied to at least one surface of the at least one substrate; a heater, wherein the heater applies heat to the at least one substrate, and wherein the at least one substrate is heated to a temperature between 25°C and 500°C; and a dopant application device, wherein the dopant application device includes at least one crucible containing the dopant and placed within the reaction chamber, wherein the dopant includes an intercalation dopant, wherein the at least one substrate includes a monolayer or multilayer graphene (MLG) strip, wherein the monolayer or multilayer graphene strip includes an etched pattern, wherein the etched pattern includes an edge, wherein the edge is exposed to the dopant, and wherein the pressure is at least partially generated by the thermal expansion of gases in the reaction chamber.

9. The apparatus according to claim 8, wherein, This intercalation doping reversibly inserts atoms, molecules, or ions between the layers of the multilayer graphene (MLG) strip.

10. The apparatus according to claim 8, wherein, The pressure is applied in the form of gas.

11. The apparatus according to claim 8, wherein, The pressure is applied mechanically.

12. The apparatus according to claim 8, wherein, The at least one substrate includes at least one wafer, wherein the diameter or side length of the at least one substrate is between 25 mm and 450 mm.

13. The apparatus according to claim 8, wherein, The solid-phase dopant is sublimated into the gas phase.

14. The apparatus according to claim 8, wherein, The dopant application device includes at least one movable pressure piston designed not to contact the at least one substrate.

15. A pressure-accelerated intercalation doping method, the method comprising the steps of: providing a reaction chamber, a heater, and a dopant application device; providing one or more wafers or substrates, wherein, The single or multiple wafers or substrates are disposed within the reaction chamber, wherein the diameter or side length of the single or multiple wafers or substrates is between 25 mm and 450 mm; the single or multiple wafers or substrates are loaded into the reaction chamber; heat is applied to the single or multiple wafers or substrates using a heater, wherein the single or multiple wafers or substrates are heated to a temperature between 25°C and 500°C; a pressure in the range of 1.1 bar to 500 bar is applied to at least one surface of the single or multiple wafers or substrates; wherein a dopant application device introduces and / or retains dopant within the reaction chamber; wherein the dopant includes intercalation dopant; wherein the single or multiple wafers or substrates include monolayer, few-layer, or multilayer graphene strips or other layered two-dimensional materials; wherein the monolayer, few-layer, or multilayer graphene strips or other layered two-dimensional materials include etched patterns; wherein the etched patterns include edges. The edge is exposed to the dopant; and the single or multiple wafers or substrates are processed at the temperature and pressure in the presence of at least one of the intercalation dopants in a gaseous or liquid state, wherein the pressure is at least partially generated by the thermal expansion of the gas in the reaction chamber.

16. The method according to request item 15, wherein, Intercalation doping refers to the reversible insertion of atoms, molecules, or ions between the layers of a layered two-dimensional material.

17. The method according to claim 15, further comprising the step of: treating the single or multiple wafers or substrates at the temperature and the pressure for a specific time in the presence of at least one of the intercalation dopants, wherein, The specific time is not less than the time obtained by dividing half of the maximum width of the graphene strip by the rate of intercalation doping, wherein the rate of intercalation doping depends on the type of at least one of the intercalation dopants, as well as the temperature and the pressure.

18. The method according to request item 15, wherein, The pressure is applied in the form of gas.

19. The method according to claim 15, wherein, The pressure is applied mechanically.

20. The method according to request item 15, wherein, The process involves applying an electric field to accelerate the intercalation doping.

21. The method according to request item 15, wherein, The solid-phase dopant was sublimated into the gas phase.

22. The method according to request item 15, wherein, The dopant application device includes at least one movable pressurizing piston designed not to contact the single or multiple wafers or substrates.

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