Electronic traps and P b centers at the Si/SiO2 interface: Band-gap energy distribution

Abstract

Energy distribution of Pb centers (⋅Si≡Si3) and electronic traps (Dit) at the Si/SiO2 interface in metal-oxide-silicon (MOS) structures was examined by electric-field-controlled electron paramagnetic resonance (EPR) and capacitance-voltage (C-V) analysis on the same samples. Chips of (111)-oriented silicon were dry-oxidized for maximum Pb and trap density, and metallized with a large MOS capacitor for EPR and adjacent small dots for C-V measurements. Analysis of C-V data shows two Dit peaks of amplitude 2×1013 eV−1 cm−2 at Ev+0.26 eV and Ev+0.84 eV. The EPR spin density reflects addition or subtraction of an electron from the singly occupied paramagnetic state and shows transitions of amplitude 1.5×1013 eV−1 cm−2 at Ev+0.31 eV and Ev+0.80 eV. This correlation of electrical and EPR responses and their identical chemical and physical behavior are strong evidence that ⋅Si≡Si3 is a major source of interface electronic traps in the 0.15–0.95 eV region of the Si band gap in unpassivated material.

The density of states in silicon nanostructures determined by space-charge-limited current measurements

“…The steep rise in N(E) toward the Fermi level might not represent the real density of states but appears to arise from an inaccuracy of this method, because this inaccuracy generally occurs in the evaluation of N(E) using step-by-step or differential methods. 17 The deduced N(E), which is minimum at the center of the energy gap ͑Fermi level͒, is similar to the commonly observed U-shape trap distribution observed at the crystalline Si-SiO 2 interface [18][19][20][21] or to the density of states observed in amorphous Si. 10 The origin of ␥ϭ4 in the stretched exponential is not clearly understood; however, we consider that both the various energy levels originating from the size distribution of nanocrystallites and the coexistence of the tissue ͑amor-phous͒ phase with nanocrystals generate the randomness expressed by a stretched exponential distribution.…”

The ultra-sensitive electrical detection of spin-Rabi oscillation at paramagnetic defects

“…P b centers are trivalent Si atoms at the c-Si/SiO 2 interface. They dominate interface trapping and recombination, they are paramagnetic when uncharged [15,16] and they are strongly localized, anisotropic electronic states [17]. For the c-Si (111) surface orientation, all P b centers point into a direction perpendicular to the interface.…”

Extraction of additional interfacial states of silicon nanowire field-effect transistors

“…However, the peak energy levels of the interfacial state density distribution in Fig. 3͑a͒ are not consistent with the peak energy levels of P b0 and P b1 on ͑100͒, [16][17][18][19][20]23 ͑110͒, 21,23 and ͑111͒-oriented 16,17,[21][22][23] silicon/silicon dioxide interfaces. These facts indicate that the interfacial states of the SiNW nFETs are physically different from those P b0 and P b1 on ͑100͒, ͑110͒, and ͑111͒-oriented surfaces.…”