Comparison of the Effect of Boron and Phosphorus Impurities on Solid Phase Epitaxial Regrowth of Amorphous Silicon

1989 ◽  
Vol 157 ◽  
Author(s):  
Young-Jin Jeon ◽  
M.F. Becker ◽  
R.M. Walser
Keyword(s):  
Amorphous Silicon ◽  
Isothermal Annealing ◽  
Solid Phase ◽  
Laser Interferometry ◽  
Electron Pairs ◽  
Quadratic Equations ◽  
Low Concentrations ◽  
Fractional Ionization ◽  
Reported Data

ABSTRACTThis work was concerned with comparing the relative effects of boron and phosphorus impurities on the solid phase epitaxial (SPE) regrowth rate of self-ion amorphized layers in silicon wafers with (100) orientation. We used previously reported data measured by in situ, high precision, cw laser interferometry during isothermal annealing for temperatures from 450°C to 590°C, and concentrations in the range from 7.8×1018 cm-3 to 5×l020 cm-3 for boron (NB), and from 5×l017 cm-3 to 3×1020 cm-3 for phosphorus (Np) impurities. The basis for the comparison was a recently developed model that extends the Spaepen-Turnbull model for silicon recrystallization to include ionization enhanced processes.The experimental data for bom boron and phosphorus exhibited the linear variation in regrowth rate expected for low concentrations of implanted hydrogenic impurities having a concentration-independent fractional ionization in amorphous silicon. In the linear range the relative enhanced regrowth rate produced by these impurities can be expressed as a product of their, relative fractional ionizations, and the relative amount the rate constant for reconstruction is altered by localizing an electron, or a hole, at the reconstruction site. Assuming that a localized hole and electron equally softened the potential barrier for reconstruction, the experimental results indicated that boron had an ?40 meV lower barrier to ionization in amorphous silicon than phosphorus.The variations in the SPE regrowth rates with higher concentrations of both implanted boron and phosphorus were well fit by quadratic equations, but with different curvatures (+ and - for B and P respectively). This result was interpreted to indicate that SPE regrowth was further enhanced by localized hole pairs, but retarded by localized electron pairs.

Study of Enhanced Solid Phase Epitaxy of Amorphous Silicon with Low Concentrations of Implanted Phosphorous

1988 ◽  
Vol 128 ◽  
Author(s):  
Young- Jin Jeon ◽  
Won Woo Park ◽  
M. F. Becker ◽  
Rodger. M. Walser
Keyword(s):  
Amorphous Silicon ◽  
Annealing Temperature ◽  
Solid Phase ◽  
Functional Dependence ◽  
Laser Interferometry ◽  
Low Concentrations ◽  
Fractional Increase ◽  
Relative Change ◽  
Phosphorous Concentration

ABSTRACTIn this work we measured the functional dependence of the solid phase epitaxial (SPE) regrowth of amorphous silicon on the implanted phosphorous concentration, Np. The growth rates of self-ion amorphized layers in silicon wafers with (100) substrate orientation were measured by in situ, high precision, isothermal cw laser interferometry for temperatures from 460°C to 590°C, and concentrations in the range 2x1017 cm-3<Np<4x1020 cm-3. For low impurity concentrations, the fractional increase in the intrinsic SPE growth velocity ΔV/Vi depended linearly on Np as previously established for boron. For a given impurity concentration, the relative change V/Vi decreased with increasing annealing temperature.

Concentration Dependence of Arsenic on Solid Phase Epitaxial Regrowth of Amorphous Silicon

1989 ◽  
Vol 157 ◽  
Author(s):  
Young-Jin Jeon ◽  
M. F. Becker ◽  
R. M. Walser
Keyword(s):  
Amorphous Silicon ◽  
Low Dose ◽  
Solid Phase ◽  
Functional Dependence ◽  
Nonlinear Function ◽  
Laser Interferometry ◽  
High Dose ◽  
Temperature Dependent ◽  
Fractional Ionization ◽  
Dose Levels

ABSTRACTIn this work we measured the functional dependence of the solid phase epitaxial (SPE) regrowth rate, V, of amorphous silicon on the concentration of implanted arsenic (n-type) impurity, NAs. The SPE regrowth rates of self-ion amorphized layers in silicon wafers with (100) substrate orientation were measured by in situ, high precision, cw laser interferometry during isothermal annealing for temperatures from 470 °C to 580 °C, and concentrations in the range 1.5×1018cm−3 ≤NAs≤3.5×1020 cm−3.In the concentration range 7×1018 cm−3≤NAs≤2.2×1019 cm3, selected from the medium dose sample, the SPE regrowth data satisfied a linear equation; V/Vi=1+NAS/Ni, where Ni(T) was fit to an Arrhenius form obtained from the temperature dependent intersections of the SPE regrowth rate data with the concentration axis and Vi(T) was the temperature dependent apparent intrinsic SPE regrowth rate at zero impurity concentration. A similar linear dependence was obtained earlier for boron (B) and phosphorus (P).However, unlike B and P, an enhancement of SPE regrowth was observed for samples implanted with As in the concentration range 3×1018 cm−3 ≤NAS≤ 1.3×1019 cm−3, selected from the low dose sample. This result indicates that arsenic implanted at low dose levels has a higher fractional ionization in amorphous silicon than either boron or phosphorus implanted at the same dose.In the high dose samples with arsenic concentrations ≤NAs 2.2×1019 cm−3, the SPE regrowth rate varied nonlinearly with NAS. The nonlinear function had a negative curvature similar to that observed previously for P.

Stress Induced During the Solid-phase Crystallization of Amorphous Silicon Deposited by LPCVD

1995 ◽  
Vol 403 ◽  
Author(s):  
T. Mohammed-Brahim ◽  
K. Kis-Sion ◽  
D. Briand ◽  
M. Sarret ◽  
F. Lebihan ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Solid Phase ◽  
Chemical Vapor ◽  
In Situ Monitoring ◽  
Crystallization Time ◽  
Solid Phase Crystallization ◽  
Pressure Chemical ◽  
Hall Effect Measurements ◽  
Deposition Techniques

AbstractThe Solid Phase Crystallization (SPC) of amorphous silicon films deposited by Low Pressure Chemical Vapor phase Deposition (LPCVD) using pure silane at 550'C was studied by in-situ monitoring the film conductance. The saturation of the conductance at the end of the crystallization process is found transient. The conductance decreases slowly after the onset of the saturation. This degradation is also observed from other analyses such as ellipsometry spectra, optical transmission and Arrhenius plots of the conductivity between 250 and 570K. Hall effect measurements show that the degradation is due to a decrease of the free carrier concentration n and not to a decrease of the mobility. This indicates a constant barrier height at the grain boundaries. The decrease of n is then due to a defect creation in the grain. Hence, whatever the substrate used, an optimum crystallization time exists. It depends on the amorphous quality film which is determined by the deposition techniques and conditions and on the crystallization parameters.

Application of Solid Phase Epitaxy for Measuring Dangling Bond Densities and Impurity Ionization in Amorphous Silicon

1990 ◽  
Vol 205 ◽  
Author(s):  
R. M. Walser ◽  
Young-Jin Jeon
Keyword(s):  
Amorphous Silicon ◽  
Solid Phase ◽  
Recent Model ◽  
Solid Phase Epitaxy ◽  
Dangling Bond ◽  
Bond Model ◽  
Low Concentrations ◽  
Impurity Ionization ◽  
Considerable Support ◽  
Good Agreement

AbstractAccording to a recent model [1], the enhancement in the rate of the solid phase epitaxial regrowth (SPER) of silicon produced by implanted impurities is determined by the superposition of reconstruction at sites that capture neutral, and ionized, three-fold coordinated dangling bond states. Considerable support for this model is derived from experiments on ionization-enhanced SPER in silicon. In this paper we discuss how this dangling bond model (DBM) could be used to determine the densities of neutral dangling bonds and ionized impurities in amorphous silicon from these experimental results. Both densities, determined by a self-consistent calculation, are in good agreement with those measured by other types of experiments. This result provides further support for the DBM and indicates that simultaneous SPER and ESR measurements could make it possible to depth profile low concentrations of ionized impurities in amorphous silicon.

Real Time Monitoring of the Crystallization of Hydrogenated Amorphous Silicon

2005 ◽  
Vol 862 ◽  
Author(s):  
Paul Stradins ◽  
David Young ◽  
Howard M. Branz ◽  
Matthew Page ◽  
Qi Wang
Keyword(s):  
Amorphous Silicon ◽  
Real Time ◽  
Interference Fringe ◽  
Time Window ◽  
Solid Phase ◽  
Hydrogenated Amorphous Silicon ◽  
Optical Reflectance ◽  
Cutoff Energy ◽  
Hydrogenated Amorphous

AbstractIn-situ real-time optical reflectance spectroscopy is applied to investigate structural changes as hydrogenated amorphous silicon (a-Si:H) loses H and crystallizes at elevated temperature. The interference fringe spectrum (cutoff energy and amplitude) mainly characterize changes in the bulk, while the the crystal Si (c-Si) direct-transition ultra-violet reflectance signatures reveal the presence of any crystalline phase at the surface. Effusion of atomic hydrogen is monitored by a decrease of the interference fringe cutoff energy and is thermally activated with about 1.7 eV. In a-Si:H on glass, optical reflectance spectra are consistent with 2.8 eV activated homogeneous nucleation and growth of a small grain (˜ 100 nm) polycrystalline phase. In contrast, a-Si:H on c-Si crystallizes by solid phase epitaxy with very different spectral kinetics. Our measurements reveal the temperature-time window for thermal crystallization of a-Si:H for photovoltaic device applications, and highlight the versatility of the in-situ spectral reflectance monitoring.

Solid-phase epitaxy of undoped amorphous silicon by in-situ postannealing

2012 ◽  
Vol 520 (8) ◽  
pp. 3271-3275 ◽  
Author(s):  
Oliver Skibitzki ◽  
Yuji Yamamoto ◽  
Markus Andreas Schubert ◽  
Bernd Tillack
Keyword(s):  
Amorphous Silicon ◽  
Solid Phase ◽  
Solid Phase Epitaxy

Solid-phase epitaxy of amorphous silicon films by in situ postannealing using RPCVD

2011 ◽  
Vol 60 (1) ◽  
pp. 13-17 ◽  
Author(s):  
Oliver Skibitzki ◽  
Yuji Yamamoto ◽  
Markus Andreas Schubert ◽  
Günter Weidner ◽  
Bernd Tillack
Keyword(s):  
Amorphous Silicon ◽  
Solid Phase ◽  
Silicon Films ◽  
Solid Phase Epitaxy

Ionization Enhanced Solid Phase Epitaxy of Amorphous Silicon with Aluminum Impurities

1990 ◽  
Vol 205 ◽  
Author(s):  
Young-Jin Jeon ◽  
M. F. Becker ◽  
R. M. Walser
Keyword(s):  
Amorphous Silicon ◽  
Compensation Effect ◽  
Solid Phase ◽  
Functional Dependence ◽  
Laser Interferometry ◽  
Quadratic Equation ◽  
Nonlinear Dependence ◽  
High Concentration ◽  
High Concentration Range ◽  
P Type

AbstractIn this work we measured the functional dependence of the solid phase epitaxial regrowth (SPER) of amorphous silicon on NAI, the concentration of implanted aluminum (p-type). The SPER rates of self-ion amorphized layers in silicon wafers with (100) substrate orientation were measured by in situ high precision, isothermal, cw laser interferometry for temperatures from 470 °C to 550 °C, and concentrations in the range 3×1018 cm−3 ≤NAI≤ 4.7×1020 cm−3 obtained from samples implanted with three different doses.In the concentration range 3×1018 cm−3 ≤NAI≤ 2.3×1019 cm−3, we observed a “compensation effect” in which, with increasing NAI, the SPER rate decreased below the regrowth rate in intrinsic silicon and the activation energy of SPER increased to 2.85 eV, compared to 2.72 eV for intrinsic silicon. In the range 3.3×1019 cm−3 ≤NAI≤ 5.6×1019 cm−3, the regrowth rate increased linearly with NAI as previously observed for SPER in boron, phosphorus, and arsenic implanted samples. However, due to the compensation effect, the aluminum data could not be fit to the normalized equation; V/Vi = 1 + N/Ni, as was done previously for data obtained for boron, phosphorus, and arsenic. The regrowth rate increased nonlinearly to the maximum implanted concentration of 4.7× 1020 cm−3 at which the regrowth rate was more than double the previously observed maximum rate in boron doped silicon. In the high concentration range, the SPER rate enhancement could be fit by a quadratic equation whose curvature was positive as was the case for boron. This contrasts with the negative curvature required to fit the nonlinear dependence of the SPER rate on the concentration of donor impurities such as phosphorus and arsenic.

Sign in / Sign up

Export Citation Format

Share Document