Evolution of surface morphology of vicinal Si(111) surfaces after aluminum deposition

Abstract

We have studied changes in surface morphology of vicinal Si(111) surfaces with a miscut of 1.3°in the [2 :11] direction after Al deposition at elevated temperatures. The clean surface phase separates into a (111)-oriented phase and a stepped phase. Submonolayer Al deposition at 650°C, the normal preparation temperature of the Al/Si(111)-(ǰ3×ǰ3)R30°structure, only induces minor changes in the surface morphology. However, after Al deposition at temperatures above the order-disorder phase transition temperature, the step bunches break apart into a uniform array of single height steps with an average step-step separation determined by the macroscopic miscut. From a quantitative analysis of the amount of meandering of steps and the terrace width distribution, we determined the diffusivity of steps and the strength of the repulsive step-step interaction. The repulsive interaction between steps is enhanced by the Al adsorption compared to both the high-temperature (1×1) and (7×7) phases of the clean surface.

Electric-current-induced step bunching on Si(111)

“…The present value is in reasonable agreement with the adatom charge obtained by first-principles calculation ͑without the wind force͒, 0.05͉e͉. 9 If we use an experimental A value of 0.01-0.04 eV nm at 900°C, 26 z eff Ϸ0.02͉e͉ -0.06͉e͉. These values may be slightly larger than the charge estimated from the decay of step bunches by Fu et al.…”

Step-step interaction on vicinal Si(001) surfaces studied by scanning tunneling microscopy

“…Making use of a more accurate expansion 29 for à , we calculate A = 0.46Ϯ 0.02 eV Å which agrees with the value A = 0.4Ϯ 0.1 eV Å measured by Williams et al 32 Remarkably, A of the clean surface is between about two and three times smaller than that of a surface covered with 0.25 Å of Al, where A is measured to be 1.2 eV Å. 33 The present result confirms the previous finding that the step interaction energy is highly sensitive to submonolayer coverage of metals and provides a firm starting ground for the investigation of the vicinal Si͑001͒ surfaces that we present in Sec. IV B.…”

Theoretical Study of Adsorption and Diffusion of Group IIIA Metals on Si(111)

“…There are many experimental and theoretical studies (mostly band structure calculations) on the adsorption of group IIIA, i.e., B, − Al, − Ga, ,,− and In − ,,,,− on Si(111) surface, concerning the geometric and electronic structure, the surface changes associated with metal diffusion on the surface, the growth of group IIIA films on Si(111), and the properties induced by the adsorption of M on the Si(111) surface.…”

“…There are many experimental and theoretical studies (mostly band structure calculations) on the adsorption of group IIIA, i.e., B, [2][3][4][5][6][7] Al, [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] Ga, 14,15,[22][23][24][25][26][27][28][29][30][31][32] and In [13][14][15]17,21,23,[33][34][35][36][37][38][39][40][41][42][43][44] on Si(111) surface, concerning the geometric and electronic structure, the surface changes associated with metal diffusion on the surface, the growth of group IIIA films on Si(111), and the properties induced by the adsorption of M on the Si...…”