As the core substrate of semiconductor devices and MEMS devices, the surface step height and microstructure measurement accuracy of bulk silicon directly determine the performance and reliability of the devices. As the core equipment for microstructure characterization, the traditional contact measurement of the step instrument is prone to scratching the surface of bulk silicon. However, the eddy current sensor, with its advantages of non-contact, high precision, and high response, has become an ideal adaptation solution for step instrument bulk silicon measurement, promoting the development of bulk silicon measurement towards more precision and efficiency.

The working principle of eddy current sensors is based on electromagnetic induction effect. When high-frequency alternating current is applied to the probe coil, an alternating magnetic field is generated. As a conductive metal conductor, the surface of the silicon body will induce a closed vortex like eddy current. The reactive magnetic field generated by the eddy current will change the impedance of the probe coil, and the impedance change is in a precise linear relationship with the distance between the probe and the surface of the silicon body. This provides core theoretical support for step height measurement. The resistivity, relative permeability, and other parameters of bulk silicon are stable and highly matched with the measurement characteristics of eddy current sensors, which can effectively avoid material interference and ensure measurement accuracy.

In the measurement of silicon in step instruments, eddy current sensors solve the core pain point of traditional contact measurement. Traditional contact step meters use diamond probes to contact the surface of silicon, which can easily cause scratches on its smooth surface, especially for thin silicon and micro nano step structures. Probe pressure may also cause deformation of the silicon, affecting measurement results. The eddy current sensor adopts a non-contact measurement method, with a small gap between the probe and the surface of the bulk silicon, and can complete the measurement without direct contact, which not only avoids surface damage but also eliminates measurement errors caused by contact pressure.

This application solution also has significant technological advantages and is suitable for the diverse needs of silicon measurement. The resolution of eddy current sensors can reach nanometer level, which can accurately capture the step height differences on the surface of bulk silicon from nanometer to micrometer level, meeting the strict requirements of semiconductor devices for micro size; It has a fast response speed and can achieve rapid scanning measurement of the surface of bulk silicon, greatly improving measurement efficiency and adapting to the detection needs of bulk silicon samples. At the same time, the sensor has strong anti-interference ability and is not affected by slight oil stains or dust on the silicon surface. It is also compact in size and can be flexibly integrated into the scanning system of the stair step instrument to adapt to the measurement of different specifications of bulk silicon samples.

In practical applications, the combination of eddy current sensors and step gauges has been widely used in the research and development, production testing, and other scenarios of bulk silicon devices. In the bulk silicon etching process, the height of the etching step can be accurately measured to optimize the etching parameters; In MEMS bulk silicon structure processing, real-time monitoring of microstructure can be achieved to ensure the accuracy of device structure. Compared to traditional measurement methods, this approach not only improves measurement accuracy and efficiency, but also reduces the loss of bulk silicon samples, providing technical support for the high-quality development of the semiconductor industry.

With the development of bulk silicon devices towards miniaturization and high precision, the application of eddy current sensors in step measurement will continue to deepen. By optimizing the sensor probe design and improving signal processing accuracy, the measurement range can be further expanded, the measurement resolution can be improved, and the measurement needs of silicon micro nano structures can be better adapted. In the future, this technology will continue to drive innovation in bulk silicon measurement technology, providing more reliable measurement guarantees for technological breakthroughs in fields such as semiconductors and MEMS.