Characteristics and Charge Storage of Silicon Quantum Dots Embedded in Silicon Nitride Film
Silicon-rich silicon nitride (SRSN) films were prepared by plasma-enhanced chemical vapor deposition. Silicon quantum dots (Si QDs) were obtained after high temperature annealing. Fourier transform infrared spectroscopy, x-ray diffraction, Raman and x-ray photoelectron spectroscopy spectra were used to describe the structure behaviors of the as-deposited and annealed samples. The hydrogen-related bonds disappeared when the annealing temperature was above 650°C for 30 min. Crystalline and amorphous Si QDs co-existed in the SRSN film annealed at 1100°C. The photoluminescence (PL) spectra of the SRSN under Xe lamp were studied. The red-shift and blue-shift of PL peaks were ascribed to the size and phase evolution of Si QDs, and the PL intensity strongly depended on the passivation condition of Si QDs. The charge storage effect was investigated on Al/the SRSN annealed at 1100°C/n-Si/Al structure by capacitance–voltage (C–V) measurements. The C–V hysteresis width increased to 1.8 V at the sweeping voltage of ±10 V.