Microreflectance difference spectrometer based on a charge coupled device camera: surface distribution of polishing-related linear defect density in GaAs (001)

Abstract

We describe a microreflectance difference (microRD) spectrometer based on a charge coupled device (CCD), in contrast to most common RD spectrometers that are based on a photomultiplier or a photodiode as a light detector. The advantage of our instrument over others is the possibility to isolate the RD spectrum of specific areas of the sample; thus topographic maps of the surface can be obtained. In our setup we have a maximum spatial resolution of approximately 2.50 microm x 2.50 microm and a spectral range from 1.2 to 5.5 eV. To illustrate the performance of the spectrometer, we have measured strains in mechanically polished GaAs (001) single crystals.

In Situ Characterization of Epitaxy

“…Lastly, recent work reported the use of microreflectance difference spectroscopy to resolve RAS signals at a resolution of square microns [50]. Laterally patterned Si was used as a substrate to grow GaP with layers of alternating orientations as a result of differences in the GaP sublattice occupancy from antiphase domain differences created at steps.…”

Polarization contrast linear spectroscopies for cubic semiconductors under stress: macro‐ and micro‐reflectance difference spectroscopies

“…Micro-reflectance difference spectroscopy (μRDS) measures the RD spectra coming from specific areas of the sample; thus, topographic maps of the surface can be obtained [42]. This can be accomplished by using a charge coupled device (CCD) instead of the most common spectrometers based on a Photomultiplier or Photodiode as light detectors.…”

“…1(c). A detailed discussion can be found elsewhere [42]. Figure 7 shows the spatial dependence of density on the surface of the sample.…”

“…The image was generated by performing a linear interpolation among neighbor points. The topography of the surface is groove-like with the symmetry of the defects (lines along [110] direction), yielding the spatial dependence of the density of linear defects [42,43]. The brown and yellow colors indicate a maximum and minimum amplitude of the OA, respectively.…”

Study of Nanoscratching Process of GaAs Using Molecular Dynamics

“…Gallium arsenide (GaAs) wafer has applications in numerous fields, such as illumination, photoelectric detection, and solar energy, due to its excellent mechanical and electronic properties. For example, GaAs wafers with a super smooth surface are needed for the production of high-quality flexible solar cells and light emitting diode (LED) [1,2]. At present, chemical mechanical polishing (CMP) is critically required to fabricate GaAs wafer with a super smooth and planar surface.…”