Tunneling Characteristics Depending on Schottky Barriers and Diffusion Current in SiOC

To obtain a diffusion current in SiOC, the aluminum doped zinc oxide films were deposited on SiOC/Si wafer by a RF magnetron sputtering. All the X-ray patterns of the SiOC films showed amorphous phases. The level of binding energy of Si atoms will lead to an additional potential modulation by long range Coulombic and covalent interactions with oxygen ions. The growth of the AZO film was affected by the characteristics of SiOC, resulting in similar trends in XPS spectra and a shift to higher AZO lattice d values than the original AZO d values in XRD analyses. The charges trapped by the defects at the interlayer between AZO and SiOC films induced the decreased mobility of carriers. In the absence of trap charges, AZO grown on SiOC film such as the sample prepared at O2 = 25 or 30 sccm, which has low charge carrier concentration and high mobility, showed high mobility in an ambipolar characteristic of oxide semiconductor due to the tunneling effect and diffusion current. The structural matching of an interface between AZO and amorphous SiOC enhanced the height of Schottky Barrier (SB), and then the mobility was increased by the tunneling effect from band to band through the high SB.