Semiconductor material stress measurement system and method based on photoelastic modulation technology

Abstract

The invention relates to the technical field of electronic equipment control, in particular to a semiconductor material stress measurement system based on a photoelastic modulation technology. The system comprises a laser light source, at least one reflector, a through hole, a polarizer, a photoelastic modulator, a first wave plate, a measured sample, a second wave plate, an analyzer and an infrared detector which are arranged in sequence, a laser beam emitted by the laser light source is guided into a measuring light path through at least one reflector, the polarizer converts the laser beam into linearly polarized light, the laser beam passes through the photoelastic modulator and then is converted into modulated polarized light which is continuously switched back and forth from the linearly polarized light to circularly polarized light, the modulated polarized light passes through a measured sample to form a birefringence signal, the infrared detector converts the birefringence signal into an electric signal, and the electric signal is transmitted to a computer for processing through the measuring circuit. The system has the beneficial effects that the requirement of other methods based on photoelastic modulation on the stress of the tested sample is met, and the tested sample in the system does not need to rotate.

Description

technical field [0001] The invention relates to the technical field of electronic equipment control, in particular to a semiconductor material stress measurement system and method based on photoelastic modulation technology. Background technique [0002] The traditional method of using birefringence technology to measure the stress of semiconductor materials is generally based on infrared photoelastic technology, using a plane or circular polarized light system to measure the birefringence of the material to measure the stress state in the material, where figure 1 Shown is a plane polarized light measurement system, including a light source L, a polarizer P, a sample M to be tested, and an analyzer A; figure 2 Shown is a circularly polarized light measurement system, including a light source L, a polarizer P, a quarter-wave plate Q1, a sample M to be measured, a quarter-wave plate Q2, and an analyzer A. The advantage of using a planar or circularly polarized light system t...

AI Technical Summary

Problems solved by technology

And adopt photoelastic modulation device and lock-in amplifier technology to measure birefringence in the prior art and also be limited by some conditions, such as some techniques need to rotate the measured sample to obtain the size and direction of birefringence; It is not necessary to rotate the measured sample to obtain the size and direction of the birefringence, but it is required that the phase generated by the birefringence of the measured sample must be small enough to approximate the angle, so it cannot meet the needs of actual measurement

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