Effect of the Flash Annealing on the Impurity Distribution and the Electronic Structure in the Inversion Layer

Abstract

We investigated the relationship among the number of flash annealing times to obtain Si clean surface and the change of arsenic dopant concentration and subband levels using secondary ion mass spectroscopy (SIMS) and angle-resolved photoelectron spectroscopy(ARPES). The SIMS result shows that the first five times of the flash annealing already induces significant reduction of the dopant concentration in agreement with the recent work [Pitter et al., J. Vac. Sci. Technol. B 30, 021806 (2012)]. We found the energies of hole subband levels rapidly decrease as the number of the flash annealing times increases. We calculated the subband levels in a broadened confinement potential taking the dopant reduction determined by SIMS into account. The energy separations of the calculated subband levels were in good agreement with the ARPES results.

Unusual energy separation of subbands in Si(111) p-channels induced by In adsorption

“…It is already known that As atoms out-diffuse from the surface through high temperature FA. 21,22) Therefore, we supposed the concentration of the As dopant to be a lower value, so that the calculated energy separations from TPA become closer to those from ARPES. In the case of Sample 1, the calculated energy separations from TPA become closer to those from ARPES within the range of 0.02 and 0.01 eV in the case of Sample 2 as shown in Table IV.…”

Empirical potential profile model for subbands with unusual energy separation in Si(111) p-type inversion layer

“…1(a), 1(b)] has been reported using ultra-violet photoelectron spectroscopy. [8][9][10][11][12][13][14] Through the studies, some of the observed subbands quantum levels were found to be inconsistent with the result of the triangular potential approximation (TPA) calculation. In the TPA, the band edge profile V(z) in the space charge layer is approximated to a linear line so that the subband energy levels are obtained analytically.…”

“…XPS results showed no proof of the penetration of the metal atoms, 13) whereas SIMS results indicated that the dopant (As) concentration was decreased in the surface region. 12,13) Though the non-uniform impurity distribution was found, the actual V(z) curve which produced the observed energy level has still been missing.…”