Semiconductors & Photovoltaics

Structured substrates are widely employed in semiconductor and photovoltaics research and development. The high demands on device quality and reliability make it increasingly important to have a detailed knowledge of the inherent strain and crystalline properties of such device structures. The WITec imaging techniques provide the opportunity to analyze the samples comprehensively regarding their chemical and physical characteristics.

WITec imaging systems provide a wide range of imaging techniques which can be flexibly combined in one microscope to significantly increase the insight provided by measurement results. Confocal Raman imaging provides chemical information, AFM detects topography, structure, and physical properties such as stiffness, adhesion, etc. of the sample’s surface, and SNOM high-resolution measurements can optically reach beyond the diffraction limit. All WITec instrument configurations can be upgraded at any point to adapt the system to new or extended requirements.

Application Examples

RISE Microscopy (Raman-SEM) of a LT GaAs sample. The Raman image is overlayed on the SEM image. Raman image: Yellow: Gold substrate; Red: GaAs. 50 x 50 µm², 300 x 300 pixels = 90,000 spectra, 34 ms integration time per spectrum.
Stress map in Si around a laser-drilled hole on a Si solar cell device.
Raman-SEM image of structures in a GaN layer. Top: SEM image; Middle: confocal Raman image in x-y-direction; Bottom: 3D confocal Raman image.

AFM image of an integrated circuit.
Raman and AFM images of the same sample area at three different positions on a wafer.