Far-field and near-field photon emission microscopy for semiconductor devices

• Main Author: Ding, Yuzhou
• Other Authors: Poenar Daniel Puiu
• Format: Final Year Project
• Language: English
• Published: 2012
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Optics, optoelectronics, photonics
• Online Access: http://hdl.handle.net/10356/49629
• Institution: Nanyang Technological University

Optical information is the primary channel for human being to understand the physical world. In electronics industry, photon emission microscopy (PEM) is an established tool used in defect isolation. The correlation between the light emission and local currents discussed in literature shows the possibility of more convenient device characterization with PEM techniques. The first part of the project explores the usefulness of PEM other than defect isolation, and quantifies local current distribution within individual semiconductor device. Some of the observations with PEM techniques are validated with TCAD computer simulation, and more physical insights of the devices are revealed. In the second part of the project, a new type of Scanning Near-field Photon Emission Microscopy (SNPEM) has also been utilized. This is in response to the megatrend of device miniaturization in semiconductor industry: The device features continue to shrink beyond the diffraction limit of far-field imaging techniques. Near-field approach is chosen to overcome this limit. Based on near-field optics, the resolution of imaging system is no longer dependent on wavelength of light for imaging. Instead, it depends on the size of light collection probe, and the distance between probe and emission source. The developed SNPEM system is integrated with far-field imaging optics, and capable to bias semiconductor devices at wafer level. The sensitivity of the system is enhanced by lock-in amplifier, and the resolution is optimized through the fabrication of near-field probe. The system demonstrates a resolution down to 100 nm in near-field optical image of FinFET devices. Novel phenomenon in optical image is observed for the first time, which is previously unattainable with far-field imaging system.