Epitaxy and Nucleation in Cu and Ag Doped Amorphous Si

AbstractThe competition between solid phase epitaxy and random nucleation during thermal annealing of amorphous Si implanted with the fast diffusers Cu and Ag has been studied. For low concentrations of these impurities, solid phase epitaxy proceeds with small deviations from the intrinsic rate and with the impurity remaining in the shrinking amorphous layer. At a critical metal concentration in the amorphous layer of ∼ 0.12 at.% rapid random nucleation occurs, halting epitaxy and transforming the remaining amorphous material to polycrystalline Si via grain growth. The nucleation rate is at least 8 orders of magnitude greater than the intrinsic homogeneous rate. At higher Cu concentrations nucleation is observed below the temperature needed for epitaxy (400°C). This nucleation, clearly caused by the presence of Cu or Ag in the layer, may be induced by the impurities exceeding the absolute stability concentration and starting to phase separate, leading to enhanced crystal Si nucleation in the metal rich regions.

Download Full-text

Epitaxial growth versus nucleation in amorphous Si doped with Cu and Ag

Journal of Materials Research ◽

10.1557/jmr.1993.0820 ◽

1993 ◽

Vol 8 (4) ◽

pp. 820-829 ◽

Cited By ~ 14

Author(s):

J.S. Custer ◽

Michael O. Thompson ◽

D.J. Eaglesham ◽

D.C. Jacobson ◽

J.M. Poate

Keyword(s):

Epitaxial Growth ◽

Solid Phase ◽

Intrinsic Rate ◽

Amorphous Layer ◽

Solubility Limit ◽

Solid Phase Epitaxy ◽

Metal Impurities ◽

Random Nucleation ◽

Si Doped ◽

Amorphous Si

The competition between solid phase epitaxy and random nucleation in amorphous Si implanted with Cu and Ag has been studied. At low metal concentrations, solid phase epitaxy proceeds with slight deviations from the intrinsic rate, with the impurity segregated and evenly distributed in the amorphous layer. At an impurity concentration of 0.12 at.%, rapid nucleation occurs, transforming the remaining layer into polycrystalline Si. The nucleation rate is ≥108 the intrinsic homogeneous rate. The effects of the metals on epitaxy scale with the amount of metal–Si interaction. Nucleation appears to occur when the metal impurities exceed their absolute solubility limit and begin to phase separate.

Download Full-text

Process and Mechanism of CoSi2/Si Solid Phase Epitaxy by Multilayer Reaction

MRS Proceedings ◽

10.1557/proc-580-117 ◽

1999 ◽

Vol 580 ◽

Author(s):

Bing-Zong Li ◽

Xin-Ping Qu ◽

Guo-Ping Ru ◽

Ning Wang ◽

Paul Chu

Keyword(s):

Epitaxial Growth ◽

Solid Phase ◽

Amorphous Layer ◽

Solid Phase Epitaxy ◽

Initial Stage ◽

Vital Effect ◽

Amorphous Si ◽

Kinetics Of ◽

State Amorphization

AbstractA multilayer structure of Co/a-Si/Ti/Si(100) together with Co/Ti/Si(100) is applied to investigate the process and mechanism of CoSi2 epitaxial growth on a Si(100) substrate. The experimental results show that by adding an amorphous Si layer with a certain thickness, the epitaxial quality of CoSi2 is significantly improved. A multi-element amorphous layer is formed by a solid state amorphization reaction at the initial stage of the multilayer reaction. This layer acts as a diffusion barrier, which controls the atomic interdiffusion of Co and Si and limits the supply of Co atoms. It has a vital effect on the multilayer reaction kinetics, and the epitaxial growth of CoSi2 on Si. The kinetics of the CoSi2 growth process from multilayer reactions is investigated.

Download Full-text

Crystallization and Melting of Amorphous Silicon on a Microsecond Time Scale

MRS Proceedings ◽

10.1557/proc-74-109 ◽

1986 ◽

Vol 74 ◽

Cited By ~ 4

Author(s):

G. L. Olson ◽

J. A. Roth ◽

E. Nygren ◽

A. P. Pogany ◽

J. S. Williams

Keyword(s):

Film Thickness ◽

Time Scale ◽

Laser Heating ◽

Solid Phase ◽

Solid Phase Epitaxy ◽

Amorphous Films ◽

Random Nucleation ◽

Cw Laser ◽

Time Regime ◽

Amorphous Si

AbstractMeasurements of the competition beween solid phase epitaxy, solid phase random nucleation, and melting in amorphous Si on a microsecond time scale are reported. We find that the behavior of amorphous Si under microsecond pulsed dye laser irradiation depends strongly on film thickness and temperature. In “thin” (≲1000 Å) films solid phase epitaxy is observed at temperatures up to and exceeding 1300°C with random nucleation dominating at T>1330° C; however, melting of amorphous Si does not occur. In contrast, in “thick” (2600 Å) amorphous films melting is observed at T˜1190°C. These results are discussed with respect to measurements obtained previously in the nanosecond time regime using Q-switched laser heating and in the 0.1–1 millisecond regime using “chopped beam” cw laser heating.

Download Full-text

Kinetics of solid phase epitaxy in thick amorphous Si layers formed by MeV ion implantation

Applied Physics Letters ◽

10.1063/1.103477 ◽

1990 ◽

Vol 57 (13) ◽

pp. 1340-1342 ◽

Cited By ~ 82

Author(s):

J. A. Roth ◽

G. L. Olson ◽

D. C. Jacobson ◽

J. M. Poate

Keyword(s):

Ion Implantation ◽

Solid Phase ◽

Solid Phase Epitaxy ◽

Amorphous Si ◽

Kinetics Of

Download Full-text

Amorphous‐Si/crystalline‐Si facet formation during Si solid‐phase epitaxy near Si/SiO2 boundary

Journal of Applied Physics ◽

10.1063/1.333958 ◽

1984 ◽

Vol 56 (2) ◽

pp. 279-285 ◽

Cited By ~ 40

Author(s):

Yasuo Kunii ◽

Michiharu Tabe ◽

Kenji Kajiyama

Keyword(s):

Solid Phase ◽

Solid Phase Epitaxy ◽

Amorphous Si ◽

Facet Formation

Download Full-text

The Effect of Hydrogen on the Kinetics of Solid Phase Epitaxy in Amorphous Silicon

MRS Proceedings ◽

10.1557/proc-205-45 ◽

1990 ◽

Vol 205 ◽

Cited By ~ 9

Author(s):

J. A. Roth ◽

G. L. Olson ◽

D. C. Jacobson ◽

J. M. Poate ◽

C. Kirschbaum

Keyword(s):

Growth Rate ◽

Solid Phase ◽

Intrinsic Value ◽

Amorphous Layer ◽

Inert Gas ◽

Solid Phase Epitaxy ◽

Depth Profiles ◽

Kinetics Of ◽

Crystal Interface ◽

Good Agreement

AbstractThis paper discusses the intrusion of H into a-Si layers during solid phase epitaxy and the effect of this H on the growth kinetics. We show that during annealing in the presence of water vapor, H is continuously generated at the oxidizing a-Si surface and diffuses into the amorphous layer, where it causes a reduction in the epitaxial growth rate. The measured variation of growth rate with the depth of the amorphous/crystal interface is correlated with the concentration of H at the interface. The diffusion coefficient for H in a-Si is determined by comparing measured depth profiles with calculated values. Hydrogen intrusion is observed even in layers annealed in vacuum and in inert gas ambients. Thin (<;5000 Åthick) a-Si layers are especially susceptible to this effect, but we show that in spite of the presence of H the activation energy for SPE derived earlier from thin-layer data is in good agreement with the intrinsic value obtained from thick, hydrogen-free layers.

Download Full-text

Solid phase epitaxy of implantation-induced amorphous layer in (11̄00)- and (112̄0)-oriented 6H-SiC

Journal of Applied Physics ◽

10.1063/1.1338983 ◽

2001 ◽

Vol 89 (3) ◽

pp. 1986 ◽

Cited By ~ 23

Author(s):

Masataka Satoh ◽

Yuuki Nakaike ◽

Tomonori Nakamura

Keyword(s):

Solid Phase ◽

Amorphous Layer ◽

Solid Phase Epitaxy

Download Full-text

Lateral Solid Phase Epitaxy of Amorphous Si Films under Ultrahigh Pressure

10.7567/ssdm.1992.a-1-4 ◽

1992 ◽

Author(s):

H. Ishiwara ◽

H. Wakabayashi ◽

K. Miyazaki ◽

K. Fukao ◽

A. Sawaoka

Keyword(s):

Solid Phase ◽

Ultrahigh Pressure ◽

Solid Phase Epitaxy ◽

Amorphous Si ◽

Si Films

Download Full-text

Polycrystalline Si Films Fabricated by Low Temperature Selective Nucleation and Solid Phase Epitaxy Process

MRS Proceedings ◽

10.1557/proc-485-67 ◽

1997 ◽

Vol 485 ◽

Cited By ~ 3

Author(s):

Claudine M. Chen ◽

Harry A. Atwater

Keyword(s):

Thin Film ◽

Grain Size ◽

Crystal Growth ◽

Incubation Time ◽

Solid Phase ◽

Solid Phase Epitaxy ◽

Grain Sizes ◽

Random Nucleation ◽

Nucleation Sites ◽

Si Films

AbstractWith a selective nucleation and solid phase epitaxy (SNSPE) process, grain sizes of 10 μm have been achieved to date at 620°C in 100 nrm thick silicon films on amorphous SiO2, with potential for greater grain sizes. Selective nucleation occurs via a thin film reaction between a patterned array of 20 rnm thick indium islands which act as heterogeneous nucleation sites on the amorphous silicon starting material. Crystal growth proceeds by lateral solid phase epitaxy from the nucleation sites, during the incubation time for random nucleation. The largest achievable grain size by SNSPE is thus approximately the product of the incubation time and the solid phase epitaxy rate. Electronic dopants, such as B, P, and Al, are found to enhance the solid phase epitaxy rate and affect the nucleation rate.

Download Full-text