The Application of Synthetic Diamonds in High-Tech Field
The physical properties of diamonds not only make them the king of gemstones, but also an important material in modern industry, especially in high-tech industries. The development of synthetic diamond technology has further expanded the application of diamonds. Today, apart from diamond jewelry, diamonds have been widely used in many fields such as drilling (from oil and deep earth drilling to drilling holes in teeth), cutting (from cutting marble to cutting gemstones), aerospace (from cabin windows to space probes), electronics (from electronic instruments to supercomputer chips), and heat exchange (from large boilers to kitchen utensils), or have shown great potential for use. Currently, about 100 million carats of diamonds are mined each year from diamond mines, while the amount of synthetic industrial diamonds reached 400 million carats in 1995, and 75% of the 100 million carats of natural diamonds are industrial diamonds.
The low friction coefficient of diamonds makes it less likely for food to stick on the bottom of the pan. The high hardness of diamonds ensures that kitchen utensils are not easily damaged. The high thermal conductivity of diamonds ensures a near-uniform temperature distribution across different parts of the pan,greatly reducing the risk of food burning. Moreover, people will no longer need to place a copper sheet at the bottom of the pan as they currently do.
Since the 1950s, the semiconductor electronics industry has experienced periodic replacements of materials such as germanium, silicon, and silicon carbide. In the foreseeable future, synthetic diamonds will replace silicon carbide as the next generation of semiconductor materials. At least for now, people can't imagine a better semiconductor material than diamond. The advantages of synthetic diamond as a semiconductor material lie mainly in the following aspects: a. Among all materials, the movement speed of electrons and holes in a strong electric field inside a diamond is the highest, making it the ideal material for high-speed, high-frequency amplifiers; b. The breakdown voltage of the diamond is the highest among all semiconductor materials, making it the ideal material for high-power amplifiers (power is directly proportional to the square of the voltage); c. In a diamond crystal, the energy required for an electron to transition from a covalent bond to an ionic bond is 5.5 electron volts, while the band gaps of silicon and germanium are 1.1 and 0.7 electron volts, respectively. This means that diamonds can work normally at higher temperatures (>1000℃, while silicon semiconductors cannot work normally above 200℃). At normal operating temperatures, the current leakage caused by diamond semiconductors is minimal; d. The permittivity of diamonds (capacitance) is only half that of conventional semiconductor materials, making them ideal for working in the microwave and millimeter-wave spectrum. In the 1980s, President Reagan's Star Wars program in the United States invested heavily in the application research and development of diamonds in the semiconductor field.
Conventional bearings all require lubricating oil to maintain operation. If a diamond film is coated on the surface of the bearing, the friction coefficient of the bearing will be much lower and it will not be easily damaged.
(4) Diamond Window
Diamonds are completely transparent to electromagnetic radiation in a considerable spectral range, including visible light and infrared light.Diamonds have strong resistance to high-speed raindrops and dust. Diamonds can quickly conduct heat generated by air friction.These characteristics of diamonds make them important for space exploration.In 1978, during the exploration of Venus by the Pioneer Venus spacecraft, a diamond window with a diameter of 18.2mm and a thickness of 2.88mm was installed (Harlow, 1998).Due to Venus having an atmospheric pressure nearly 100 times that of Earth, the diamond window was capable of withstanding immense heat and pressure as the probe descended through the Venusian atmosphere.
The advent of large-area CVD-synthesized diamond films has enabled the cutting of thousands of diamond heat sinks for use in the electronics industry from a single diamond film. Additionally, it has opened up application areas that natural diamonds lack, with one of them being the usage in three-dimensional multicore modules for supercomputers.
The processing speed of large-scale computers that utilize integrated circuits depends on the speed at which signals are transmitted between different chips. This transmission speed, in turn, relies on the arrangement of the chips. When chips are placed only on a single plane, the distance between them can significantly impact the computational speed, especially when dealing with a large number of chips. To overcome this limitation, the concept of three-dimensional chip modules emerged. In this approach, a large number of two-dimensional chip layers are tightly stacked together in the vertical direction. By adopting this three-dimensional chip module design, the computational speed of the computer can be greatly enhanced.However, a significant consequence of this approach is the release of a large amount of heat during high-speed signal transmission between chips. In the case of the Cray-3 supercomputer, this issue was addressed by using liquid helium between the chip layers to cool them. The CVD method, which can synthesize large-area diamond films, offers a solution to this crucial problem. The synthesized diamond has high purity, making it a perfect electrical insulator. By directly placing the chips on the diamond film, this key issue of supercomputers can be effectively resolved.