{ silicon carbide substrate }

  • How Does Cutting Technology Affect Silicon Carbide Substrate Quality and Subsequent Processes?

    In the manufacturing process of SiC (silicon carbide) substrate, the cutting of SiC ingot is a crucial step. It not only directly determines the surface quality and dimensional accuracy of the substrate, but also has a decisive influence on cost control. The key parameters determined by the cutting process, such as surface roughness (Ra), total thickness deviation (TTV), warping (BOW) and bending (WARP), have a profound impact on the final quality, yield and production cost of the substrate. In addition, the quality of cutting is also directly related to the efficiency and cost of subsequent grinding and polishing processes. Therefore, the development and progress of SiC ingot cutting technology is of great significance to improve the level of the entire silicon carbide substrate manufacturing industry.

     

    High-precision silicon carbide substrate

     

    Diamond saw blade, circular saw blade, elimination, large Ra difference, large warpage, wide slit, slow speed, low precision, loud noise

    Electric spark: wire + current, eliminated, wide slit, large surface burn layer thickness

    Mortar line: copper-plated stainless steel wire + mortar, thin wafer, high yield, low loss, slow speed and low precision, pollution, low life of wire saw

    Diamond wire: consolidated abrasive + diamond wire, high efficiency, narrow slit, environmental protection, deep damage layer, fast line wear, substrate warping

     

    First, the status quo of SiC ingot cutting technology

    With the advancement of science and technology, SiC ingot cutting technology has made remarkable progress. At present, the mainstream cutting technology mainly includes mortar wire cutting, diamond wire cutting and laser stripping technology. These technologies differ in cutting efficiency, surface quality, cost, etc., providing a variety of options for SiC substrate manufacturing.

     

    Second, the main cutting technology characteristics analysis

    1. Mortar wire cutting: As a traditional cutting technology, mortar wire cutting cuts SiC ingot through the line containing abrasive and mortar. Although this method is low cost and easy to apply in mass production, it is slow to cut and may leave a deep damaged layer on the substrate surface, affecting subsequent processing efficiency and substrate quality.

     

     

    2. Diamond wire cutting: Diamond wire cutting technology uses diamond particles as abrasives to cut SiC ingot through high-speed rotating lines. This method not only has fast cutting speed, but also shallow surface damage layer, which helps to improve the quality and yield of substrate. Therefore, diamond wire cutting technology is gradually widely used in the field of SiC substrate manufacturing.

     

     

    3. Laser stripping technology: Laser stripping technology is an emerging cutting method, which uses the thermal effect of the laser beam to separate the SiC ingot. This technology can provide very precise cuts, significantly reducing substrate damage, and thus improving the quality of the substrate. However, due to the relatively high cost at present, laser stripping technology is mainly used in high-end fields.

     

    Third, the impact of cutting technology on substrate quality and subsequent processes

    The choice of cutting technology not only affects the direct quality of SiC substrate, but also has an important impact on its subsequent processing. High-quality cutting technology can reduce substrate surface damage, reduce the difficulty and cost of grinding and polishing, thereby improving the efficiency and effectiveness of the entire production process. Therefore, in the manufacturing process of SiC substrate, it is very important to choose the right cutting technology.

     

    In summary, the development and progress of SiC ingot cutting technology is of great significance for improving the quality, efficiency and cost control of SiC substrate. With the continuous progress of science and technology and the intensification of market competition, the future SiC ingot cutting technology will develop in the direction of more efficient, more accurate and more economical. At the same time, with the rapid development of new energy, semiconductor and other fields, the market demand for SiC substrate will continue to grow, providing a broad space and opportunities for the development of SiC ingot cutting technology.

  • Technological Advancements To Improve Silicon Carbide Substrate CMP Efficiency

    With the continuous progress of semiconductor technology, silicon carbide (SiC), as a high-performance material, has shown great application potential in the field of power electronic devices. However, in the preparation process of silicon carbide substrate, surface quality control is particularly critical, especially after thinning, grinding and polishing and other processes to obtain ultra-smooth surface. Among them, chemical mechanical polishing (CMP), as one of the key steps, is of great significance for removing the damaged layer left by the previous process and achieving high surface levelling. However, the traditional CMP process faces the problem of low material removal rate (MRR), which directly affects the production efficiency and cost. Therefore, exploring new technologies to improve the CMP efficiency of SiC substrate has become the focus of current research.

     

    Ultra-smooth surface silicon carbide substrate

     

    1. Basic principles and challenges of SiC substrate CMP

    The surface damage depth of the thinned or ground SiC substrate is usually 2-5μm and requires further treatment by CMP.

    CMP technology is based on the "chemical + mechanical" composite principle, through the combination of oxide layer formation and mechanical removal, to achieve surface smoothing.

     

    2. Low MRR is the main problem of SiC substrate CMP, and the CMP efficiency of SiC is significantly lower than that of silicon substrate.

    The impact of low MRR on production efficiency and cost:

    Lower MRR results in longer time consuming SiC substrate CMP steps, increasing processing time and cost.

    Even if the existing CMP method can produce qualified 4H-SiC substrate, low efficiency is still the bottleneck restricting its large-scale application.

     

    CMP polishing process

    CMP polishing process

     

    3. Technical progress to improve CMP efficiency:

    To meet the low MRR challenge, the industry has developed double-sided, batch polishing technology.

    These advanced technologies have significantly reduced CMP man-hours, such as the CMP polishing time for a single batch of 10 substrates from 3-5 hours to 1 hour.

    Double-sided polishing technology not only improves efficiency, but also helps maintain consistency and flatness on both sides of the substrate.

     

     

    In summary, the improvement of chemical-mechanical polishing efficiency of silicon carbide substrate is the key to promote its wide application. Through the development of advanced technologies such as double-sided and batch polishing, the problem of low material removal rate in the traditional CMP process is effectively solved, the processing time is significantly shortened, and the production cost is reduced. In the future, with the continuous improvement of the performance requirements for SiC materials and the continuous innovation of polishing technology, we have reason to believe that the preparation of SiC substrates will be more efficient and economical, laying a solid foundation for the further development of power electronic devices. Therefore, the continuous exploration and optimization of CMP process will be an important way to promote the wide application of SiC materials in the semiconductor field.