UV Sensitivity of MOS Structures with Silicon Nanoclusters

Area of Science:

• Materials Science
• Nanotechnology
• Semiconductor Physics

Background:

• Metal-Oxide-Semiconductor (MOS) structures are fundamental electronic components.
• Silicon nanostructures offer unique optical and electronic properties.
• Understanding UV sensitivity in MOS devices is crucial for optoelectronic applications.

Purpose of the Study:

• To investigate the selective UV sensitivity of MOS structures incorporating silicon nanoclusters.
• To compare the UV response of structures with silicon nanocrystals versus amorphous silicon nanoparticles.
• To elucidate the underlying mechanism for UV selectivity.

Main Methods:

• Fabrication of SiOₓ films with varying silicon content.
• Controlled furnace annealing to form silicon nanocrystals and amorphous silicon nanoparticles.
• X-ray Photoelectron Spectroscopy (XPS) and Transmission Electron Microscopy (TEM) for material characterization.
• Electrical measurements to assess UV light responsivity.

Main Results:

• Formation of silicon nanocrystals in a SiO₂ matrix and amorphous silicon nanoparticles in a SiO₁.₇ matrix was confirmed.
• Both structures demonstrated selective sensitivity to UV light.
• The silicon nanocrystal structure showed approximately 4 times higher responsivity to 365 nm UV light compared to green light at 4V.
• The UV selectivity was more pronounced in the silicon nanocrystal-containing structure.

Conclusions:

• Silicon nanoclusters within MOS structures enable selective UV light detection.
• The observed UV sensitivity is attributed to photocarrier generation primarily by short-wavelength radiation within the nanoclusters.
• These findings suggest potential for developing novel UV photodetectors based on silicon nanostructures.