A broadband micro-region semiconductor photocurrent imaging system and method

Abstract

The application discloses a wide-band micro-region semiconductor photocurrent imaging system and method, and belongs to the technical field of semiconductor testing. The system comprises a temperature adjusting module, a picosecond pulse laser output module, an optical chopper, a microscopic imaging module, an electric piezoelectric displacement table and a lock-in amplifier. The temperature adjusting module is used for adjusting the temperature of a semiconductor device to be tested to 4K to 296K. The picosecond pulse laser output module is used for outputting a pulse laser beam in a wave band of 430nm to 2000nm. The optical chopper is used for modulating the laser beam into an optical pulse signal with a fixed modulation frequency. The lock-in amplifier is used for applying a bias voltage to the semiconductor device to be tested and collecting a photocurrent signal under the fixed modulation frequency. The electric piezoelectric displacement table is used for moving the semiconductor device to be tested point by point under a low-temperature environment. The microscopic imaging module is used for synchronously acquiring a surface topography image and constructing a photocurrent spatial distribution map. The application solves the technical problem that the current technology cannot simultaneously realize multi-wavelength excitation, weak signal extraction and micro-region spatial resolution imaging under an extremely low-temperature environment.

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