The effect of hydrogen passivation on the intersubband absorption in δ-doped multiple Si layers is studied. The passivation is carried out using a dc plasma of hydrogen in a quartz reactor. Fourier transform infrared spectroscopy is used to measure the absorption spectra and the effectiveness of the passivation of boron acceptors. The intersubband absorption intensity is reduced considerably upon H passivation and the effectiveness of the hydrogenation is a function of the boron concentration in the δ layers and the duration of the exposition to the H plasma. A resonance peak at 1870 cm-1 is observed after passivation, characteristics of a boron-hydrogen complex. After annealing the samples in nitrogen at sufficiently high temperature, the absorption intensity recovers nearly to its initial value and the process of hydrogenation is reversed. The activation energy of the dissociation of the boron-hydrogen complex is calculated and found to be 1.9±0.1 eV, in reasonable agreement with the B-H complex dissociation energy in bulk Si.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)