Electrical Properties and Stability of Supersaturated Phosphorus‐Doped Silicon Layers

Abstract

Supersaturated solutions of phosphorus in silicon were obtained by ion implantation and pulsed ruby laser annealing. The dependence of electron mobility and electrical resistivity on carrier density was accurately determined by Hall effect and resistivity measurements. Maximum dopant concentration was 5×1021 normalatom/cm3 , corresponding to a resistivity of 110 μΩ · cm and to an electron mobility of 11 cm2/V · sec. The stability of these alloys was analyzed by isochronal and isothermal annealing. In the more heavily doped samples a remarkable deactivation of the dopant was verified also for thermal treatments of 1 hr at 300°C. TEM examinations showed a large amount of precipitates with density and size depending on supersaturation. Finally it was observed that the electron mobility depends only on the carrier density and is unaffected by the electrically inactive phosphorus, even when present at very high concentrations.

Double crystal X-ray analysis of phosphorus precipitation in supersaturated SiP solid solutions

“…Since preceding works [9,141 have shown that high phosphorus supersaturations give rise to the formation of very small precipitates, we can hypothesize that this defect is a perfectly coherent Sip precipitate of cubic structure with lattice parameter n = = 0.5241 nm [22]. I n this case, an expression like (3) can be applied to describe the strain as a function of the precipitated phosphorus concentrations.…”

Morphological stability during solidification of silicon incorporating metallic impurities

“…1,2,3,4 In recent years, silicon supersaturated with sulfur has shown strong sub-band gap infrared absorption and device response. 5,6,7 This has led to interest in alternative dopants, including Au, Zn, Fe, Ti, Co, and others.…”

Mechanism of Surface Bump Defect Formation in Phosphorus Doped Polysilicon-Silicon Nitride Film Stack

“…Once the stable SiO 2 is formed on the surface, the segregation of coefficient of less than 1 for P prevents further accumulation of P near the surface, preventing the seat formation mechanism for bump defect formation. The formation local P-rich surface regions can be explained by the possible migration of P along the grain boundaries in the Si during the initial heat-up before actual SiN x deposition process in the furnace, which can provide sufficient thermal energy crystallization of a-Si and P-diffusion along grain boundaries [4][5][6].…”