Effects of post oxidation of SiO2/Si interfaces in ultrahigh vacuum below 450 °C

Growing SiO2 layer by wet-chemical oxidation of Si surfaces before growth another insulating film(s) is a used method to passivate interfaces in applications (e.g., solar cell, photodiode) at low temperatures (LT) below 450 °C. We report on potential LT ultrahigh-vacuum (UHV) treatments combined with the oxidation, investigating effects LT-UHV after and growing Al2O3 film top SiO2/Si. This modifies SiO2/Si found (i) decrease defect-level density, (ii) increase negative fixed charge (iii) carrier lifetime for Al2O3/SiO2/p-Si, as compared state-of-the-art SiO2/p-Si reference without LT-UHV. X-ray photoelectron spectroscopy shows that treatment decreases amount Si+3 oxidized atoms chemically grown also carbon contamination. In order pave way further tests silicon technology, we present design simple UHV instrument. The above-described benefits are reproduced 4-inch wafers means instrument, which utilized make complementary native oxide diode sidewalls reverse bias leakage current diodes.