With the continuous promotion of pressure sensor research and application fields, the substrate materials of pressure sensors are also different. It is more common to select materials with specific properties for device manufacturing.
Pressure sensor base material:
The substrate material is the basis for the manufacture of pressure sensors. The choice of different substrate materials not only affects the performance of the pressure sensor, but also determines the process selection in the device fabrication process. At present, the substrate materials for pressure sensor processing are mainly divided into silicon-based materials and non-silicon-based materials, in which the processing technology of silicon-based devices is currently widely used due to its compatibility with the existing integrated circuit processing technology.
The types of silicon-based materials are mainly divided into silicon materials including polycrystalline silicon, single crystal silicon, and amorphous silicon, silicon-on-insulator including SOl and SOG, and emerging silicon carbide semiconductor materials.
The early pressure sensors were manufactured based on copper, the material of conventional pressure devices, as the base material. It has become the mainstream process for device processing and industrialization, but because devices have higher requirements in terms of device performance and size compared to integrated circuits.
In order to improve the deficiencies of conventional silicon substrate materials in the manufacture of S devices of different types and applications in terms of structure and performance, based on the improvement of conventional silicon substrate materials, Siemens proposed to use SOI substrates to manufacture pressure sensors, and Stanford University proposed to use Monolithic silicon carbide is used as the substrate to manufacture the pressure sensor.
Since then, due to the needs of the integrated industrialization of silicon-based materials for device integration, and the need to manufacture a complete sensor structure and supporting ASIC system based on the base material to achieve a complete integrated pressure sensing system, the Netherlands NX company proposed the use of SOI substrates to make MEMS sensors and circuits. Structural integrated system, the company proposed to use silicon carbide substrate to make MEMS sensor and circuit structure integrated system.