Electronic properties of sulfur passivated undoped-n+ type GaAs surface studied by photoreflectance

Photoreflectance and Raman Study of Surface Electric States on AlGaAs/GaAs Heterostructures

“…As we can see, (4) corresponds to a linear function with slope (ℎ ) 3/2 , which can be determined using experimental data by a linear fitting of the plot of (4/3 )( − ) 3/2 versus the index number . Next, can be determined using (2).…”

“…Frequently, the surfaces of semiconductor devices are passivated in order to stabilize their chemical nature and to eliminate reactivity. Ammonium polysulfide (NH 4 ) 2 S x has been frequently used to passivate the surface of GaAs with covalently bonded sulfur atoms [1][2][3][4][5][6][7][8][9]. However, sulfur passivation only provides short-term surface stability.…”

“…Photoreflectance and Raman spectroscopy are very useful approaches that have been widely used for the study of GaAs-based devices [4,[23][24][25][26][27][28][29][30][31]. The PR technique has been used to study the AlGaAs/GaAs system in numerous reports, which were focused on determining the origin of Franz-Keldysh oscillations (FKO) that usually are observed at the PR spectra [24][25][26][27][28][29][30][31].…”

A complex Fourier transformation study of the contactless electroreflectance of an undoped-n+GaAs structure

“…These perfect FKOs lead to accurate determination of the built-in electric field in the undoped layer and the Fermi level pinning on the semiconductor surface. Thus, the UN + /P + structure is often used in modulation spectroscopy for the characterization of electronic properties of semiconductor surfaces [3][4][5][6].…”