Segregation and Trapping of Gold During Ion-Induced Crystallization of Amorphous Si

1988 ◽  
Vol 100 ◽  
Author(s):  
J. M. Poate ◽  
J. Linnros ◽  
F. Priolo ◽  
D. C. Jacobson ◽  
J. L. Batstone ◽  
...  

ABSTRACTA novel regime of crystal growth and segregation has been observed. Amorphous Si layers were uniformly doped with Au and epitaxial crystallization was induced in the temperature range 250–420°C using 2.5 MeV Ar ion irradiation. The Au segregation at the amorphous/crystal interface is analogous to behavior at liquid/solid interfaces except that the interfacial segregation coefficient of 0.007 at 320°C is independent of velocity between 0.6 and 6A/sec. This process results in the trapping of Au in crystalline Si at concentrations some ten orders of magnitude in excess of equilibrium concentration.

1988 ◽  
Vol 128 ◽  
Author(s):  
J. M. Poate ◽  
D. C. Jacobson ◽  
F. Priolo ◽  
Michael O. Thompson

ABSTRACTSegregation and diffusion of impurities in amorphous Si during furnace and ion-beam-induced epitaxy will be discussed. The use of ion beams to enhance the crystal growth process has resulted in novel behavior for fast diffusers such as Au. Diffusion is enhanced in the temperature range 300–700 K with activation energies ∼0.3 eV. Segregation and trapping are analogous to behavior at liquid-solid interfaces


1986 ◽  
Vol 74 ◽  
Author(s):  
R. G. Elliman ◽  
J. S. Williams ◽  
S. T. Johnson ◽  
E. Nygren

AbstractThin amorphous layers in crystalline Si and GaAs substates have been irradiated at selected temperatures with 1.5 MeV Ne+ ions to induce either epitaxial crystallization or amorphization. In Si, such irradiation can induce complete epitaxial crystallization of a 1000 A surface amorphous layer for temperatures typically >200°C whereas, at significantly lower temperatures, layer-by-layer amorphization results. Although epitaxial crystallization can also be stimulated in GaAs by ion irradiation at temperatures >65°C, the process is non-linear with ion dose and results in poor quality crystal growth for amorphous layers greater than a few hundred Angstroms in thickness. Layer-by-layer amorphization has not been observed in GaAs.


1989 ◽  
Vol 157 ◽  
Author(s):  
J. S. Custer ◽  
Michael O. Thompson ◽  
D. C. Jacobson ◽  
J. M. Poate

ABSTRACTThe interface velocity of Au and Ag doped amorphous Si during ion beam induced epitaxy was measured using in situ time resolved reflectivity. Interfacial segregation coefficients were determined as a function of composition from numerical simulations. At 320°C Au impurities enhanced the velocity by up to a factor of 2.5 compared to the intrinsic case. Silver slightly retarded re-growth by 10 %. These effects are qualitatively similar to the case of thermal solid phase epitaxy. Using the measured impurity profiles and interface velocity, computer simulations relate the segregation coefficient to the concentrations of the impurity at the interface. In both cases, the segregation coefficient increases with increasing interfacial impurity concentration.


1991 ◽  
Vol 6 (10) ◽  
pp. 2103-2108 ◽  
Author(s):  
G. Carter ◽  
M.J. Nobes

A simple phenomenological model is developed to explain, qualitatively, the observed temperature and ion flux dependences of either recrystallization or further amorphous growth of amorphous layers in semiconductors when exposed to ion irradiation. The model includes radiation assisted annealing processes and thermally modified amorphous zone production at the amorphous-crystal interface.


2019 ◽  
Vol 523 ◽  
pp. 119628 ◽  
Author(s):  
G. Maity ◽  
R. Singhal ◽  
S. Dubey ◽  
S. Ojha ◽  
P.K. Kulriya ◽  
...  

1983 ◽  
Vol 23 ◽  
Author(s):  
Jun-ichi Chikawa ◽  
Fumio Sato ◽  
Tadasu Sunada

ABSTRACTAtomic processes at the interface in regrowth following laser induced melting were investigated by observing behavior of impurity segregation. The interfacial segregation coefficient k* was obtained from depth profiles of solute atoms redistributed by laser irradiation of uniformly doped Si, Ge, and GayAl1−yAs crystals. It was found that k*=k0 for B in Si, Ga in Ge ih the growth rate range of 1 m/s. It is concluded that rapid growth freezes a state of liquid monolayer adjacent to the interface which has the character of ideal solution from dilute to eutectic composition for dopant-silicon systems and in the entire range of composition for the mixed crystal.


Materia Japan ◽  
2004 ◽  
Vol 43 (12) ◽  
pp. 1010-1010
Author(s):  
Masaru Itakura ◽  
Noriyuki Kuwano

1990 ◽  
Vol 201 ◽  
Author(s):  
James S. Im ◽  
Jung H. Shin ◽  
Harry A. Atwater

AbstractIn situ electron microscopy has been used to observe crystal nucleation and growth in amorphous Si films. Results demonstrate that a repeated intermediate temperature ion irradiation/thermal annealing cycle can lead to suppression of nucleation in amorphous regions without inhibition of crystal growth of existing large crystals. Fundamentally, the experimental results indicate that the population of small crystal clusters near the critical cluster size is affected by intermediate temperature ion irradiation. Potential applications of the intermediate temperature irradiation/thermal anneal cycle to lateral solid epitaxy of Si and thin film device technology are discussed.


Sign in / Sign up

Export Citation Format

Share Document