Experimental, Research MPCVD Grown Diamonds

Application Preparation of high-quality single crystal diamond; Preparation of high-quality polycrystalline free-standing diamond films; Preparation of high quality polycrystalline diamond films; Preparation of various carbon nano films such as graphene, carbon nanotubes, fullerenes and diamond films. Features a. Stainless steel cavity type 6kw microwave plasma equipment, high power density; b. The water-cooled substrate stage and the water-cooled metal chamber ensure the system can work stably for a long time; c. The substrate temperature is achieved by microwave plasma self-heating; d. The vacuum measuring instrument adopts a full-range vacuum gauge, which can accurately measure the background vacuum and working gas pressure; e. The vacuum pump and valve adopt turbo molecular pump (the ultimate vacuum is 1×10-5Pa) and the rotary vane mechanical vacuum pump (the ultimate vacuum is 1Pa), and the system can automatically control the deposition pressure; f. Cooling water circulation system to ensure long-term safe and stable operation of the device under high power; g. 15-inch touch screen, PLC automatic control, can set the temperature or pressure to be constant, can save and reuse up to 20 sets of process files; Fully automatic process control module, which can stably and reliably prepare high-quality diamond films and crystals System installation requirements The following installation conditions are provided by the customer: 1. Gas connection a) Working gas path: users need to provide four channels of CH4, H2, N2 and O2, the gas pressure is 0.2MPa, and the gas purity is determined by the user according to the process requirements b) Gas interface: 1/4"VCR interface 2. Power supply a) Power supply voltage: AC 380V (± 10%), frequency 50 Hz, three-phase four wire, There is independent ground wire in the room, the efficiency of grounding resistance is 4 Ω, and the maximum power is 20kW b) It is recommended to reserve a separate air switch on the wall 1 meter away from each equipment. The specification of air switch is 4P32A and with leakage protection. c) Before making any connections, the electronic system in the system should be shut down. 3. Cooling water Customers need to provide their own industrial chillers： a) Cooling capacity：10kw b) Flow rate：>30L/min c) Recommended inlet water temperature：20℃，maximum inlet water temperature<25℃ d) Inlet water pressure：≥5.0 kg/cm2 （or head>45 m） e) System water inlet and outlet connection：φ19mm（pagoda joint） f) In order to avoid problems caused by corrosion, pure water is recommended 4. Compressed air demand for system control a) Compressed dry air (CDA): the system needs to provide CDA gas path with gas pressure ≥ 0.4MPa. b) Interface: φ 8 quick plug (pneumatic quick plug) 5. Equipment exhaust a) Customers need to prepare their own exhaust channels, and the exhaust port of the equipment is connected to the exhaust channel through the KF25 interface. Check before acceptance 1. Vacuum leakage: the leakage rate of vacuum chamber is less than 0.1torr/12h 2. Microwave leakage: the measured value is less than 2MW/cm2 (when the microwave output is 5kW) 3. Water pipe leakage: make sure the water pipe is not leaking 4. System test: the system can start and run normally, and the plasma fireball is even and stable The experimental research on Microwave Plasma Chemical Vapor Deposition (MPCVD) grown diamonds utilizes a microwave system sourced from Sairem in France, operating at a frequency of 2450±25MHz and featuring an adjustable output power ranging from 0.6 kW to 6 kW continuously. This system employs a 3-stub tuner for microwave tuning and a mode conversion antenna to facilitate the TM013 operating mode. Ensuring safety, the microwave leak is maintained below 2 mw/cm2. The vacuum system involved in this setup has an operating pressure range spanning from 10 to 250 Torr, with automatic pressure control between 40 and 250 Torr. It relies on a 4.4 L/s rotary-vane vacuum pump and boasts excellent vacuum integrity, measuring less than 1.0x10-9 Pa·m³/sec through Helium leak detection. The pressure holding capacity ensures minimal pressure rise, staying below 0.2 Torr every 24 hours. The ultimate vacuum reaches 0.1 Pa (7.5x10-4 Torr), verified using a brand film gauge for vacuum measurement. The vacuum reactor, constructed with double-layer water-cooled stainless steel, employs a combination of metal seals and fluororubber ring seals for its load door. It has a reactor ID of φ140mm and features a 105x50mm rectangular port for the sample table window, sealed with Fluorine O-rings. Additionally, two ports with CF35 large bores, distributed at 180°, facilitate observation through watch windows. Temperature measurement windows, with a horizontal angle of 25-30° and 180° distribution, enable temperature monitoring from different angles. The sample stage consists of an electric lift water-cooled substrate platform with an adjustable height range of 0 to 70mm. It ensures complete coverage of the plasma fireball for molybdenum substrates with diameters ≥50mm, operating at 5000W and 180 Torr, with substrate temperature ranging from 250 to 1400℃, depending on process parameters. The gas channel incorporates flowmeters and flow control valves imported from Japan and offers four channels through the system-provided 4-channel MFC, with maximum flow rates for H2 at 1000sccm, CH4 at 100sccm, O2 at 20sccm, and N2 at 2sccm. Temperature measurements are carried out using a German Raytek infrared temperature measurement system, covering a temperature range from 300 to 1300℃. The system's software interface features a 15-inch touch screen with PLC control, providing a user-friendly operating experience. It supports two user levels, engineer and operator, with user authority management functionality. Safety is ensured through automatic protections for water and air shortages, power supply phase failures, fireball jumps, over temperature overload, ignition, and more. Process control is facilitated through the setup of up to 10 sets of process recipes, each comprising 40 rows of data. The system automates various processes, including air extraction, ignition, heating, cooling, and more, thereby reducing the workload for system operators.