Characteristic electronic defects at the Si-SiO2 interface

Abstract

On unannealed, thermally oxidized silicon, electron spin resonance reveals an oriented interface defect which is termed the Pb center and identified as the trivalent silicon defect. Deep level transient spectroscopy (DLTS) reveals two broad characteristic peaks in the interface-state distribution: one ∼0.3 eV above the silicon valence-band maximum and a second ∼0.25 eV below the conduction band. Isochronal anneals of oxidized silicon, coated with aluminum, show that the spin density and the densities of the two DLTS peaks have the same annealing kinetics. On large-area, Al-gated capacitors the spin density can be modulated with an applied voltage; sweeping the silicon band gap at the interface through the Fermi level reveals that the spin density is approximately constant over the central region of the band gap but decreases near the band edges. The variation of the spin density with gate voltage identifies an amphoteric center with both electronic transitions in the band gap. Both the annealing behavior and the voltage dependence of the Pb center support the conclusion that these transitions correspond to the two characteristic peaks in the interface-state distribution. The ∼0.6 eV separation of the peaks is the effective correlation energy of the dangling orbital on a trivalent silicon defect at the Si-SiO2 interface. The similarity between the disordered interface and amorphous silicon is discussed.

Defects and relaxation during the negative bias temperature instability in PMOSFET

“…At 300°C, all interface states have recovered after 20h, while at 150°C, only 3.5% have been repassivated by hydrogen species. These results are in agreement with results concerning the diffusion of hydrogen species [10]- [11].…”

Growth, Thermodynamics, and Electrical Properties of Silicon Nanowires

“…[210][211][212] It could also be shown that these P b centers are indeed the main source for the interface trap states. [213][214][215][216][217][218][219] Furthermore, it was found that the P b centers correspond to trivalent Si atoms bonded to just three other Si atoms. 214,220 In a crude approximation, one could say that the interface trap states are nothing more than Si dangling bonds; and thinking of interface states as dangling Si bonds, it is also intuitively understandable that they can act as both donors and acceptors.…”

Photoluminescence characterization of nano‐size defects in sub‐surface region of silicon wafers

“…The large peak corresponds to the deep level at 0.3 eV above the silicon valence band maximum (E v C 0.3 eV). 7 This coincides with the reported interface gap state between the silicon substrate and the oxide layer, which is called the Pb centre. Figure 5 shows the correlation between the average intensity of the band-edge emission and the interface gapstate density.…”