• 专利标题:   System for growing crystalline material, has optical emission spectrometer (OES) that controls parameter in closed loop and maintains required proposition of plasma constituent for growth of crystalline materials in microwave plasma reactor.
  • 专利号:   IN202011039555-A, WO2022054072-A1, US2022084793-A1
  • 发明人:   SHARDA T, BHANDARI R, RAJNEESH B, TARUN S
  • 专利权人:   SIGMA CARBON TECHNOLOGIES, SIGMA CARBON TECHNOLOGIES
  • 国际专利分类:   C01B032/25, C23C016/27, C23C016/511, G01J003/443, H01J037/32, C30B025/02, C30B029/04, C23C016/52
  • 专利详细信息:   IN202011039555-A 12 Feb 2021 H01J-037/32 202123 Pages: 34 English
  • 申请详细信息:   IN202011039555-A IN11039555 13 Sep 2020
  • 优先权号:   IN11039555

▎ 摘  要

NOVELTY - The system has a microwave plasma reactor (102), a microwave generator (104), an optical emission spectrometer (OES) (106) and a pressure controller (108). The OES and the pressure controller are integrated with the microwave generator to form an Integrated Microwave Generator System (IMGS) (100). The IMGS is comprised with an IMGS controller (110). The OES is arranged to provide a real-time feedback loop to the IMGS controller based on microwave plasma input from microwave plasma reactor, to control parameter in a closed loop and maintain required proposition of plasma constituents for growth of crystalline materials in microwave plasma reactor. The parameter is provided with a power, pressure, power density, and pulsed power. The plasma constituents are comprised with atomic hydrogen, Hydroxide, nitrogen, nitrile, gamma hydrogen, beta hydrogen, hydrogen, hydrocarbon, alpha hydrogen, Bohrium, carbon monoxide, Diatomic carbon, delta carbon, Dioxidanyliumyl, dioxide, oxygen and argon. USE - Microwave Plasma Chemical Vapor Deposition (MPCVD) system for growing crystalline material such as Diamonds, Carbon Nitride, Boron Nitride, Silicon Nitride, Gallium Nitride, Silicon, Silicon Dioxide, Silicon Carbide, Zirconia, Tin Selenide, Gallium Oxide Whiskers and Nanowires, Carbon Nanotubes, Zinc Oxide Nanowires, and Graphene (all claimed). ADVANTAGE - The system provides dramatic improvement in the quality and production yield of diamonds. The configured IMGS replaces individual devices such as microwave source and pressure controller in the MPCVD system to produce high-quality diamonds. DETAILED DESCRIPTION - The diamonds are grown without the need of direct temperature control by an optical pyrometer. The growth of diamonds is achieved with precision of 1% or lower variation in the normalized concentration of plasma constituents. The growth of low birefringence high quality single crystalline electronic grade diamond is achieved with low birefringence on any type of diamond seed. The growth of optical grade single crystalline diamond for gem and other applications is achieved with high growth rates in larger areas and without any post growth treatment such as low pressure high temperature or high pressure high temperature. The OES is arranged to monitor real-time concentration of plasma constituents just above the growing surface of diamonds and feed the realtime information to the IMGS controller to automatically adjust power density to maintain the concentration of plasma constituents on the growing surface of the diamonds. The IMGS is facilitated with a function of providing a pulsed power output in a precisely controlled manner of the peak power with duty cycle. The function when integrated with the plasma constituents concentration feed, improves three-dimensional uniformity of the growth of diamonds. The IMGS provides the same microwave power within 50 MHz of the specified frequency of 2450 MHz and 915 MHz as output, which helps in optimizing production yield of each MPCVD unit, and stabilizes the batch to batch production in a single MPCVD unit and from unit to unit. The chip-based microwave generator is comprised with a set of semiconductor chips and devices for generating microwave frequencies. The set of semiconductor chips and devices is comprised with a voltage-controlled oscillator (VCO) and a phase-locked loop (PLL) chip. The PLL chip is comprised with a negative feedback system comprising a multiplier, a loop filter and a VCO connected together to provide the feedback in a loop, wherein the VCO generates a sine wave and its frequency is determined by an external applied voltage. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the MPCVD system for growing crystalline materials. IMGS (100) Microwave plasma reactor (102) Microwave generator (104) OES (106) Pressure controller (108) IMGS controller (110)