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In the high voltage field, particularly for high-voltage devices above 20,000V, the SiC epitaxial technology still faces several challenges. One of the main difficulties is achieving high uniformity, thickness, and doping concentration in the epitaxial layer. For the fabrication of such high-voltage devices, a 200um thick silicon carbide epitaxial wafer with excellent uniformity and concentration is required.

Both epitaxial and diffused wafers are essential materials in semiconductor manufacturing, but they differ significantly in their fabrication processes and target applications. This article delves into the key distinctions between these wafer types.

The process of monocrystalline silicon growth predominantly occurs within a thermal field, where the quality of the thermal environment significantly impacts crystal quality and growth efficiency. The design of the thermal field plays a pivotal role in shaping temperature gradients and gas flow dynamics within the furnace chamber. Furthermore, the materials used in constructing the thermal field directly influence its lifespan and performance.

There are six classifications for semiconductors, which are classified by product standard, processing signal type, manufacturing process, usage function, application field, and design method.

The CVD process for SiC wafer epitaxy involves the deposition of SiC films onto a SiC substrate using a gas-phase reaction. The SiC precursor gases, typically methyltrichlorosilane (MTS) and ethylene (C2H4), are introduced into a reaction chamber where the SiC substrate is heated to a high temperature (usually between 1400 and 1600 degrees Celsius) under a controlled atmosphere of hydrogen (H2).

In traditional silicon power device fabrication, high-temperature diffusion and ion implantation stand as the primary methods for dopant control, each with its advantages and disadvantages. Typically, high-temperature diffusion is characterized by its simplicity, cost-effectiveness, isotropic dopant distribution profiles, and lower introduction of lattice damage. Conversely, ion implantation, though complex and costly, enables precise independent control over dopant concentration and depth but introduces a significant number of point defects and extended defects into the substrate.