Yellow River Cyclone launches R&D project for 3-inch and optical-grade CVD polycrystalline diamond thin films

May 27, Henan Yellow River Cyclone Co., Ltd. announced on the investor relations platform that Yellow River Cyclone will develop 3-inch diameter and optical-grade CVD polycrystalline diamond films, and establish a CVD polycrystalline diamond detection center to promote the application of CVD diamond films in thermal, optical, electrical, acoustic, and electrochemical aspects.

        I. What is CVD polycrystalline diamond film?

CVD stands for Chemical Vapor Deposition. It is different from mining natural diamonds or synthesizing diamonds by simulating high-temperature and high-pressure environments underground (HTHP method). The principle is to introduce carbon-containing gas (such as methane CH4) and hydrogen (H2) into a vacuum or low-pressure reaction chamber. A plasma is generated by a specific energy source (such as microwave, hot wire, arc, etc.) to decompose the gas molecules. Under precisely controlled temperature (usually 800°C - 1200°C) and pressure, carbon atoms or carbon-containing groups are deposited, migrated, and arranged on the surface of the selected substrate (such as silicon wafer, molybdenum sheet, or even ceramic), finally forming a diamond structure.

        Single Crystal VS Polycrystalline

Single crystal diamond refers to the regular and continuous arrangement of atoms throughout the crystal, like a perfect crystal. It has excellent properties but is limited in size (especially large-size single crystal growth is extremely difficult and slow) and is extremely expensive.

Polycrystalline diamond film: composed of countless tiny diamond grains (usually in the nanometer to micrometer range) closely packed together. There are grain boundaries between the grains. Although grain boundaries bring some minor differences in performance (such as slightly lower thermal conductivity and optical scattering), it solves the core bottleneck of size and cost of single crystal diamond, making large-scale and customizable production possible.

CVD polycrystalline diamond film combines the excellent properties of diamond (such as high hardness, high thermal conductivity, wide band gap, etc.) and the designability of thin films (such as thickness, shape, and attached substrate), and has important application value in many fields.

Yellow River Cyclone's 2-inch polycrystalline diamond heat sink

     II. Main Application Areas

        1. Optics

Infrared optical window: used as a protective window for infrared detectors (such as missile seekers) in aerospace and military fields.

Ultraviolet light emitting devices: using the wide band gap characteristics of diamond (band gap width 5.5 eV), research and development of solar-blind ultraviolet detectors and deep ultraviolet light emitting diodes (DUV-LEDs).

       2. Semiconductor

Heat sink devices: used as heat sink materials for 5G base station chips and laser diodes (LDs) to solve the heat dissipation bottleneck of high-frequency devices.

Power device substrate: combined with wide band gap semiconductors such as silicon carbide (SiC) and gallium nitride (GaN) to improve the performance of devices in high-frequency and high-temperature environments.

      3. Biomedical and Sensors

Biocompatible coating: used for implantable medical devices (such as artificial joints), using the chemical inertness and low friction coefficient of diamond.

High-sensitivity sensors: based on nitrogen-vacancy (NV) centers in diamonds, develop magnetic field and temperature nanosensors for bioimaging and quantum computing.

As the "ultimate semiconductor material", the thermal, optical, electrical, and quantum properties of diamond are constantly being developed. Thermal management materials, optical materials, mechanical and acoustic materials, and semiconductor materials based on diamond applications have significant advantages and huge development potential, playing an important role in modern high-tech fields and national defense industry, and are becoming a new hotspot for international competition.

With the maturity of the preparation process and the decrease in cost, the application scenarios of CVD polycrystalline diamond films will be further expanded, and it is expected to play a key role in semiconductor, quantum technology, and new energy fields in the future. Yellow River Cyclone's launch of the 3-inch and optical-grade CVD polycrystalline diamond film R&D project is not only a technological breakthrough in materials, but also a solid step towards the localization of high-end and optical core materials, injecting hard-core technological strength into "Made in China".