Abstract
Room-temperature adsorption of disilane (Si2H6) on Ge(111)-c(2×8) and subsequent thermal reactions and desorption at elevated temperatures were studied using scanning tunneling microscopy and core-level photoemission. The initial adsorption results in the formation of various surface radicals, and the reacted areas on the surface grow laterally for increasing exposures. The sticking coefficient is rather low, and an exposure greater than about 30 000 langmuirs is needed to saturate the surface. The net amount of Si deposited for the saturated surface is about one-half of an atomic layer. Thermal annealing causes the hydrogen atoms to desorb and the Si atoms to move below the surface. For annealing temperatures beyond about 630 K, the desorption of hydrogen becomes complete, all of the Si atoms move below the surface, and the resulting surface resembles the starting clean Ge(111)-c(2×8) surface except that the c(2×8) long-range order is partially destroyed. Step flow and island coarsening, similar to growth by molecular-beam epitaxy, are observed.
Original language | English |
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Pages (from-to) | 1836-1843 |
Number of pages | 8 |
Journal | Physical Review B |
Volume | 49 |
Issue number | 3 |
DOIs | |
State | Published - 1994 |
Externally published | Yes |