Bias abutment structure for MPCVD (Micro Pressure Chemical Vapor Deposition) equipment
By employing a bias abutment structure in the MPCVD equipment, independent bias voltage can be applied to the abutment ring and the growth substrate, solving the problem of insufficient cavity vacuum and bias voltage control in the prior art. This improves the nucleation efficiency and film uniformity of diamond, and enhances the fabrication efficiency of the equipment.
Patent Information
- Application Number
- CN202511371459.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-24
- Publication Date
- 2025-11-21
AI Technical Summary
Existing MPCVD equipment cannot apply different bias voltages to the abutment ring and the growth substrate while ensuring the vacuum level of the cavity. This results in insufficient targeting and flexibility of bias voltage control, making it impossible to simultaneously meet the requirements of improving diamond nucleation efficiency and optimizing electric field distribution uniformity.
A biased base structure is adopted, including components such as a ceramic sleeve, a copper stage, an insulating ring, and a spring probe. Different bias voltages are applied to the base ring and the growth substrate through an external power supply, and the cavity and the copper stage are isolated by an insulating structure to ensure that the bias voltage is accurately applied to the target position.
While maintaining the vacuum environment of the cavity, different bias voltages are applied to the abutment ring and the growth substrate respectively to promote rapid diamond nucleation, optimize the uniformity of electric field distribution, improve the nucleation efficiency and film uniformity of single crystal diamond, and enhance the preparation efficiency of MPCVD equipment.
Smart Images
Figure CN120989709A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of single-crystal diamond preparation technology, and more particularly to a bias abutment structure for MPCVD equipment. Background Technology
[0002] Diamond, as a semiconductor material with an ultra-wide bandgap, possesses irreplaceable application value in high-power, high-frequency electronic devices due to its excellent properties such as high thermal conductivity, high refractive index, high carrier mobility, and high wear resistance. Among these, single-crystal diamond, with its absence of irregular grain boundaries and low defect density, has become the core choice in this field. However, the scarcity and high price of natural large-size single-crystal diamonds make it difficult to meet the needs of industrial applications. Therefore, the artificial cultivation of single-crystal diamonds has become a research hotspot. Microwave plasma chemical vapor deposition (MPCVD) technology is the preferred method for preparing large-size single-crystal diamonds. It uses microwaves to excite the reactive gas into plasma, which is then deposited on the substrate surface to form a diamond film. It has advantages such as no pollution, good controllability, stable deposition parameters, and high film quality. Practice has shown that applying a bias voltage to the substrate can accelerate the bombardment of the substrate by the plasma, promote diamond nucleation, and improve film uniformity and deposition rate. Therefore, the bias abutment structure has become a key component in MPCVD equipment that affects the efficiency and quality of single-crystal diamond preparation.
[0003] In existing technologies, the bias application structure of MPCVD equipment typically introduces bias voltage into the reaction chamber through a single electrode or lead. The technical principle is to use the direct contact between the electrode and the substrate or stage to transfer the voltage of the external power supply to the deposition region in order to control plasma behavior. In terms of mechanical structure, simple metal probes or conductive rods are often used as bias voltage transmission mediums. They are connected to the chamber through sealing rings and fixing components to maintain the vacuum environment of the chamber. The insulation design relies on a single insulating gasket or sleeve to separate conductive components from non-conductive structures such as the chamber and stage to avoid potential leakage.
[0004] The key problem with existing technologies is that it is difficult to apply different bias voltages to the abutment ring and the growth substrate while ensuring the vacuum level of the cavity. This results in insufficient targeting and flexibility of bias voltage control, and it is impossible to simultaneously meet the requirements of improving diamond nucleation efficiency and optimizing electric field distribution uniformity. To address this issue, a bias abutment structure for MPCVD equipment is proposed. Summary of the Invention
[0005] To overcome the above deficiencies, the present invention provides a biased abutment structure for MPCVD equipment, which aims to improve the problem in the prior art that it is difficult to apply different bias voltages to the abutment ring and the growth substrate while ensuring the vacuum level of the cavity.
[0006] To achieve the above objectives, the present invention adopts the following technical solution: A bias pedestal structure for an MPCVD device, characterized in that it comprises: The cavity has a ceramic sleeve inside and a KF single-core electrode with an external power supply installed on the outside of the cavity. A base ring is provided on the top of the inner wall of the cavity. A substrate pad, wherein a growth substrate is disposed on the upper surface of the substrate pad; The copper platform is provided with an insulating structure between the copper platform and the base plate, and between the copper platform and the cavity. The device includes a probe holder and two spring probes, both of which are connected to the probe holder and placed in the cavity and the copper platform respectively after being fitted into the ceramic sleeve. A bias lead is provided between the KF single-core electrode and the spring probe. The KF single-core electrode and the spring probe are used to simultaneously and respectively apply different bias voltages to the base ring and the base pad.
[0007] As a further description of the above technical solution: The insulating structure includes an insulating ring disposed between the cavity and the base ring.
[0008] As a further description of the above technical solution: A ceramic pad is provided between the copper platform and the base plate. A positioning pin is provided inside the cavity. Both the ceramic pad and the insulating ring are made of aluminum nitride ceramic material, and an eccentric through hole is provided inside the ceramic pad.
[0009] As a further description of the above technical solution: The multiple spring probes are all threadedly connected to the probe holder. The probe holder has an internal threaded hole on one side and an external thread on the other side. The multiple spring probes are threadedly connected to the internal threaded hole.
[0010] As a further description of the above technical solution: The ceramic sleeve has a step on one side and a bayonet on the other side. The probe seat's external thread passes through the bayonet on one side of the ceramic sleeve and is fixed with a nut. The cavity and the copper platform have bias channels inside. The spring probe, the probe seat, and the connecting parts of the ceramic sleeve are all locked in the bias channels through the step on one side of the ceramic sleeve.
[0011] As a further description of the above technical solution: The bias lead is connected to the probe holder and the KF single-core electrode via a nut, and an insulating retaining ring is provided between the cavity and the copper platform.
[0012] As a further description of the above technical solution: The cavity is equipped with a water-cooled cover plate and a spiral tube. The outer wall of the cavity is equipped with symmetrical clamps. The cavity is equipped with a support sealing ring and multiple KF interfaces. The multiple KF interfaces are connected to the KF single-core electrode through the support sealing ring and the clamps to ensure the vacuum state of the cavity.
[0013] As a further description of the above technical solution: The copper stage has a positioning pin hole inside, the ceramic pad and the base pad have through holes of the same size inside, the growth substrate has blind holes of the same size inside, the positioning pin extends into the positioning pin hole inside the copper stage, and the ceramic pad, the base pad and the growth substrate are sequentially fitted into the positioning pin.
[0014] The present invention has the following beneficial effects: In this invention, the biased abutment structure, through a bias transfer component, can apply different bias voltages to the abutment ring and the growth substrate separately with the aid of an external power supply while maintaining a good vacuum environment in the cavity. This not only promotes rapid diamond nucleation, but the bias voltage of the abutment ring also optimizes the uniformity of the electric field distribution. Its insulating structure reliably isolates the abutment ring and growth substrate from the cavity and copper stage, ensuring that the bias voltage is accurately applied to the target position without causing the cavity and copper stage to become charged. At the same time, the adjustable connection between the spring probe and the probe seat ensures contact stability, and the layout of the bias leads avoids interference with the diamond film deposition quality. Thus, it achieves the effect of applying different bias voltages to the abutment ring and the growth substrate separately while maintaining the vacuum level of the cavity, solving the problem that it is difficult to achieve this operation in the prior art, improving the nucleation efficiency and film uniformity of diamond growth, and thereby improving the efficiency of MPCVD equipment in preparing single-crystal diamond. Attached Figure Description
[0015] Figure 1 This is a three-dimensional schematic diagram of a bias base structure for an MPCVD equipment proposed in this invention; Figure 2 This is a schematic diagram of the structure of a KF single-core electrode for a bias pedestal structure in an MPCVD device proposed in this invention. Figure 3 This is a schematic diagram of the cavity structure of a bias base structure for MPCVD equipment proposed in this invention.
[0016] Legend: 1. Clamp; 2. KF single-core electrode; 3. Support sealing ring; 4. Copper platform; 5. Probe holder; 6. Water-cooled cover plate; 7. Ceramic sleeve; 8. Spring probe; 9. Abutment ring; 10. Abutment pad; 11. Growth substrate; 12. Positioning pin; 13. Ceramic pad; 14. Insulating clasp; 15. Insulating ring; 16. Cavity; 17. Spiral tube; 18. Bias lead. Detailed Implementation
[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0018] Reference Figure 1 - Figure 3 The present invention provides an embodiment of a bias pedestal structure for an MPCVD device, characterized in that it comprises: The cavity 16 has a ceramic sleeve 7 inside. The ceramic sleeve 7 is embedded in the preset mounting position inside the cavity 16 and forms a tight fit with the inner wall of the cavity 16. Its axial direction is consistent with the depth direction of the cavity 16 to ensure stable position during subsequent bias transmission. The cavity 16 is equipped with an external power supply KF single-core electrode 2. The KF single-core electrode 2 is fixedly installed at the corresponding interface on the outside of the cavity 16. Its axis is perpendicular to the outer wall of the cavity 16 to facilitate stable connection of the external power supply. The top of the inner wall of the cavity 16 is provided with a base ring 9. A substrate 10 is provided on the upper surface of the substrate 10, and a growth substrate 11 is provided thereon. The copper platform 4, the base plate 10, and the cavity 16 are all provided with insulation structures; The probe holder 5 and the spring probe 8 are two spring probes. Both spring probes 8 are connected to the probe holder 5 and are placed on the cavity 16 and the copper platform 4 respectively after being fitted into the ceramic sleeve 7. A bias lead 18 is provided between the KF single-core electrode 2 and the spring probe 8. The bias lead 18 is arranged inside the cavity 16. One end of the bias lead 18 is connected to the inner end of the KF single-core electrode 2, and the other end is connected to the spring probe 8 near the probe holder 5, forming a complete bias transmission path. The KF single-core electrode 2 and the spring probe 8 are used to simultaneously and respectively apply different bias voltages to the abutment ring 9 and the abutment pad 10; The insulation structure includes an insulating ring 15, which is disposed between the cavity 16 and the base ring 9. The insulating ring 15 is annular and horizontally embedded between the cavity 16 and the base ring 9. Its outer ring and inner ring are in contact with the cavity 16 and the base ring 9 respectively, forming an insulating separation between the two. A ceramic pad 13 is disposed between the copper base 4 and the base pad 10. A positioning pin 12 is disposed inside the cavity 16. Both the ceramic pad 13 and the insulating ring 15 are made of aluminum nitride ceramic material. The ceramic pad 13 is provided with an eccentric through hole. The position of the through hole corresponds to the distribution position of the spring probes 8, so that the spring probes 8 can pass through and contact the base pad 10. Multiple spring probes 8 are connected to the probe seat 5 by threads. The probe seat 5 is provided with an internal thread hole on one side and an external thread on the other side. Multiple spring probes 8 are threaded to the internal thread hole. The ceramic sleeve 7 has a step on one side and a bayonet on the other. The external thread of the probe holder 5 passes through the bayonet on one side of the ceramic sleeve 7. The diameter of the step is larger than the diameter of the main body of the ceramic sleeve 7. The other side has an inwardly recessed bayonet, the size of which matches the diameter of the external thread of the probe holder 5. During assembly, the external thread of the probe holder 5 passes through the bayonet on one side of the ceramic sleeve 7, so that the external thread of the probe holder 5 is exposed on the ceramic sleeve 7. Then, a nut is tightened onto the exposed external thread to firmly fix the probe holder 5 and the ceramic sleeve 7 into a whole. The cavity 16 and the copper platform are then secured. 4. An internal bias channel is provided, the diameter of which is adapted to the diameter of the stepped portion of the ceramic sleeve 7. The connecting component consisting of the spring probe 8, probe seat 5, and ceramic sleeve 7 is locked in the bias channel by the step on one side of the ceramic sleeve 7, so that the entire assembly is axially positioned within the bias channel and will not move up and down. The connecting component of the spring probe 8, probe seat 5, and ceramic sleeve 7 is locked in the bias channel by the step on one side of the ceramic sleeve 7. The bias lead 18 is connected to the probe seat 5 and KF single-core electrode 2 by a nut. An insulating retaining ring 14 is provided between the cavity 16 and the copper platform 4. The cavity 16 is internally equipped with a water-cooled cover plate 6, through which coolant can flow to regulate the temperature of the upper region inside the cavity 16. A spiral tube 17 is installed inside the cavity 16, and symmetrical clamps 1 are installed on the outer wall of the cavity 16. A support sealing ring 3 is installed inside the cavity 16. Multiple KF interfaces are installed inside the cavity 16, and all KF interfaces are connected to the KF single-core electrode 2 to the cavity 16 through the support sealing ring 3 and clamps 1 to ensure the vacuum state of the cavity 16. During assembly, the connection end of the KF single-core electrode 2 is inserted into the KF interface, and the support sealing ring 3 is pressed tightly against the KF single-core electrode 2. Between the core electrode 2 and the inner wall of the KF interface, the KF single core electrode 2 is then firmly connected to the KF interface of the cavity 16 by tightening the left and right symmetrical clamps 1, thereby ensuring the vacuum state inside the cavity 16. The copper stage 4 has a positioning pin hole inside, the diameter of which matches the diameter of the positioning pin 12. The ceramic pad 13 and the base pad 10 have through holes of the same size inside, and the growth substrate 11 has blind holes of the same size inside. The positioning pin 12 extends into the positioning pin hole inside the copper stage 4, and the ceramic pad 13, the base pad 10, and the growth substrate 11 are sequentially fitted with the positioning pin 12.
[0019] Working principle: When using this bias stage structure for MPCVD equipment, the external power supply is first connected to the KF single-core electrode 2 by an operator. The KF single-core electrode 2 is sealed to the cavity 16 through the support sealing ring 3 and the clamp 1. While ensuring the vacuum environment of the cavity 16, the power is transmitted to the probe seat 5 through the bias lead 18, and then transmitted to the target position by the spring probe 8. After the spring probe 8 and the probe seat 5 are fitted into the ceramic sleeve 7, they can respectively contact the stage ring 9 and the stage pad 10, while the growth substrate 1... 1 is placed on the base plate 10, thereby enabling the application of different bias voltages to the base ring 9 and the growth substrate 11 respectively. At the same time, the insulating structure, such as the insulating ring 15, the ceramic pad 13, and the ceramic sleeve 7, can prevent the bias potential from being conducted to the cavity 16 and the copper stage 4. In addition, the positioning pin 12 can ensure the rapid positioning of the ceramic pad 13, the base plate 10, and the growth substrate 11, ensuring that the bias voltage acts stably on the deposition area. Finally, the bias voltage accelerates the interaction between the plasma and the growth substrate 11, promoting diamond nucleation and growth.
[0020] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A bias base structure for MPCVD equipment, characterized in that, include: The cavity (16) is provided with a ceramic sleeve (7) inside the cavity (16), and a KF single-core electrode (2) with an external power supply is installed on the outside of the cavity (16). A base ring (9) is provided on the top of the inner wall of the cavity (16). A base plate (10) is provided with a growth substrate (11) on its upper surface. The copper platform (4) is provided with an insulating structure between the copper platform (4) and the base plate (10), and between the copper platform (4) and the cavity (16); The probe holder (5) and the spring probe (8) are two spring probes. Both spring probes (8) are connected to the probe holder (5) and are placed on the cavity (16) and the copper platform (4) respectively after being fitted into the ceramic sleeve (7). A bias lead (18) is provided between the KF single core electrode (2) and the spring probe (8). The KF single-core electrode (2) and the spring probe (8) are used to simultaneously and respectively apply different bias voltages to the base ring (9) and the base pad (10).
2. The bias base structure for MPCVD equipment according to claim 1, characterized in that: The insulating structure includes an insulating ring (15) disposed between the cavity (16) and the base ring (9).
3. The biasing base structure for MPCVD equipment according to claim 2, characterized in that: A ceramic pad (13) is provided between the copper platform (4) and the base plate (10). A positioning pin (12) is provided inside the cavity (16). The ceramic pad (13) and the insulating ring (15) are both made of aluminum nitride ceramic material, and an eccentric through hole is provided inside the ceramic pad (13).
4. The bias base structure for MPCVD equipment according to claim 1, characterized in that: The probe holder (5) has an internal thread hole on one side and an external thread on the other side. Both spring probes (8) are connected to the probe holder (5) by threads.
5. The biasing base structure for MPCVD equipment according to claim 1, characterized in that: The ceramic sleeve (7) has a step on one side and a bayonet on the other side. The probe seat (5) passes through the bayonet on one side of the ceramic sleeve (7) with its external thread and is fixed with a nut. The cavity (16) and the copper platform (4) are provided with bias channels. The spring probe (8), the probe seat (5) and the connecting parts of the ceramic sleeve (7) are all locked in the bias channels through the step on one side of the ceramic sleeve (7).
6. The biasing base structure for MPCVD equipment according to claim 1, characterized in that: The bias lead (18) is connected to the probe base (5) and the KF single-core electrode (2) by a nut, and an insulating retaining ring (14) is provided between the cavity (16) and the copper platform (4).
7. The biasing base structure for MPCVD equipment according to claim 1, characterized in that: The cavity (16) is provided with a water-cooled cover plate (6), the cavity (16) is provided with a spiral tube (17), the outer wall of the cavity (16) is provided with symmetrical clamps (1), the cavity (16) is provided with a support sealing ring (3), the cavity (16) is provided with multiple KF interfaces, and the multiple KF interfaces are connected to the KF single-core electrode (2) and the cavity (16) through the support sealing ring (3) and the clamps (1) to ensure the vacuum state of the cavity (16).
8. A biasing base structure for an MPCVD device according to claim 3, characterized in that: The copper platform (4) has a positioning pin hole inside. The ceramic pad (13) and the base pad (10) have through holes of the same size inside. The growth substrate (11) has blind holes of the same size inside. The positioning pin (12) extends into the positioning pin hole inside the copper platform (4). The ceramic pad (13), the base pad (10), and the growth substrate (11) are sequentially fitted with the positioning pin (12).