Electron Band Alignment at Interfaces of Semiconductors with Insulating Oxides: An Internal Photoemission Study
Figure 8
Cube root of the IPE yield as a function of photon energy for MOS capacitors with a 7.4 nm thick ZrO2 insulator stacked with different SiO2 ILs as illustrated in the inset. All curves are measured under an electric field of 2 MV/cm in the insulating layer closest to Si, that is, ZrO2 in the sample with or SiO2 in other samples. The arrows and indicate onsets of direct optical transition in the silicon crystal. The spectral thresholds of electron IPE from the VB of Si into different oxides are indicated by vertical lines.
