Dopant Diffusion in Silicon Substrate during Oxynitride Process

2000 ◽  
Vol 610 ◽  
Author(s):  
Nobutoshi Aoki ◽  
Toshitake Yaegashi ◽  
Yuji Takeuchi ◽  
Makoto Fujiwara ◽  
Naoki Kusunoki ◽  
...  
Keyword(s):  
Reasonable Agreement ◽  
Nitrogen Concentration ◽  
Surface Recombination ◽  
Anomalous Behavior ◽  
Dopant Diffusion ◽  
Si Substrate ◽  
Enhanced Diffusion ◽  
Surface Recombination Rate ◽  
Oxynitride Film ◽  
Simulation Results

AbstractWe found an anomalous behavior of dopant diffusion in Si substrate during the oxynitride process. SIMS measurements showed a notably enhanced diffusion during the NO and N2O oxynitride process. The considerably enhanced diffusion was also observed in re-oxidation of oxynitride film grown by the NO annealing or NH3 nitridation of a SiO2 film. In order to simulate the enhanced diffusion, an enhancement coefficient was introduced, showing that the simulation results are in reasonable agreement with the experimental ones. We applied the diffusion model to the simulations of MOSFETs fabricated under various conditions of the oxynitride process. The device characteristics of MOSFETs were successfully reproduced by adopting a suitable dependence of nitrogen concentration CN on the surface recombination rate of interstitial Si at the oxynitride/Si substrate interface.

Formation of Counter Doped Shallow Junctions by Boron and Antimony Implantation and Codiffusion in Silicon

1997 ◽  
Vol 469 ◽  
Author(s):  
S. Solmi ◽  
R. Canteri
Keyword(s):  
Si Substrate ◽  
Junction Region ◽  
Simulation Code ◽  
Acceptor Interaction ◽  
Thermal Budget ◽  
Enhanced Diffusion ◽  
Shallow Junctions ◽  
Donor Acceptor ◽  
Simulation Results ◽  
Good Agreement

ABSTRACTVery shallow p+/n junctions (lower than 60 nm) have been fabricated by implanting Sb and subsequently BF2, at a higher dose, in a n-type Si substrate. The preamorphisation with Sb avoids the B channeling and increases the n-type doping in the junction region, thus confining the depth of the p layer. Furthermore, both the transient enhanced diffusion, being the B implanted in a preamorphized layer, and the standard diffusion, due to the pairing between donors and acceptors, are strongly reduced. This procedure allows us to obtain very shallow junctions even after annealings with relatively high thermal budget, like 800 C/8h, or 900 C/lh, or 950 C/15min or 1000 C/60s. Dopant diffusion is strongly affected by the direct donor-acceptor interaction. Good agreement between experimental and simulation results can only be obtained using a simulation code which takes into account the formation of neutral, near immobile, Sb-B pairs.

scholarly journals Self- and Dopant Diffusion in Extrinsic Boron Doped Isotopically Controlled Silicon Multilayer Structures

2002 ◽  
Vol 719 ◽  
Author(s):  
Ian D. Sharp ◽  
Hartmut A. Bracht ◽  
Hughes H. Silvestri ◽  
Samuel P. Nicols ◽  
Jeffrey W. Beeman ◽  
...  
Keyword(s):  
Multilayer Structure ◽  
Secondary Ion Mass Spectrometry ◽  
Diffusion Processes ◽  
Quantitative Description ◽  
Multilayer Structures ◽  
Dopant Diffusion ◽  
Enhanced Diffusion ◽  
Self Diffusion ◽  
Boron Doped ◽  
P Type

AbstractIsotopically controlled silicon multilayer structures were used to measure the enhancement of self- and dopant diffusion in extrinsic boron doped silicon. 30Si was used as a tracer through a multilayer structure of alternating natural Si and enriched 28Si layers. Low energy, high resolution secondary ion mass spectrometry (SIMS) allowed for simultaneous measurement of self- and dopant diffusion profiles of samples annealed at temperatures between 850°C and 1100°C. A specially designed ion-implanted amorphous Si surface layer was used as a dopant source to suppress excess defects in the multilayer structure, thereby eliminating transient enhanced diffusion (TED) behavior. Self- and dopant diffusion coefficients, diffusion mechanisms, and native defect charge states were determined from computer-aided modeling, based on differential equations describing the diffusion processes. We present a quantitative description of B diffusion enhanced self-diffusion in silicon and conclude that the diffusion of both B and Si is mainly mediated by neutral and singly positively charged self-interstitials under p-type doping. No significant contribution of vacancies to either B or Si diffusion is observed.

Effect of Energy and Dose on Transient-Enhanced Diffusion and Defect Microstructure in Low Energy High Dose As+ Implanted Si

1996 ◽  
Vol 438 ◽  
Author(s):  
V. Krishnamoorthy ◽  
D. Venables ◽  
K. Moeller ◽  
K. S. Jones ◽  
B. Freer
Keyword(s):  
Point Defects ◽  
Surface Recombination ◽  
High Dose ◽  
Enhanced Diffusion ◽  
Projected Range ◽  
Diffusion Enhancement ◽  
Defect Microstructures ◽  
Dose Dependent ◽  
Higher Doses ◽  
Defect Microstructure

Abstract(001) CZ silicon wafers were implanted with arsenic (As+) at energies of 10–50keV to doses of 2×1014 to 5×1015/cm2. All implants were amorphizing in nature. The samples were annealed at 700°C for 16hrs. The resultant defect microstructures were analyzed by XTEM and PTEM and the As profiles were analyzed by SIMS. The As profiles showed significantly enhanced diffusion in all of the annealed specimens. The diffusion enhancement was both energy and dose dependent. The lowest dose implant/annealed samples did not show As clustering which translated to a lack of defects at the projected range. At higher doses, however, projected range defects were clearly observed, presumably due to interstitials generated during As clustering. The extent of enhancement in diffusion and its relation to the defect microstructure is explained by a combination of factors including surface recombination of point defects, As precipitation, As clustering and end of range damage.

Damage Induced By A Low-Biased 92-MHz Anode-Coupled Reactive Ion Etcher Using Chlorine-Nitrogen Mixed Plasmas

1996 ◽  
Vol 442 ◽  
Author(s):  
Tadashi Saitoh ◽  
Hideki Gotoh ◽  
Tetsuomi Sogawa ◽  
Hiroshi Kanbe
Keyword(s):  
Surface Recombination ◽  
Nanometer Scale ◽  
Nonradiative Recombination ◽  
Gaussian Shape ◽  
Ridge Structure ◽  
Surface Recombination Rate ◽  
Before And After ◽  
Recombination Centers ◽  
Etched Surface ◽  
Dry Etch

AbstractDry-etch damage, introduced by a low biased 92-MHz anode-coupled reactive ion etching (RIE), in MBE-grown undoped GaAs has been characterized by photoreflectance (PR) and photoluminescence (PL) measurements. PL spectra show emission peaks at 1.516 eV (excitons) and at 1.494 eV (D-A, B-A) before etching, whereas a new emission peak at around 1.488–1.490 eV appears after the RIE. The depth distribution of this new emission center, examined by PL measurements with a combination of step wet etching, has a Gaussian-shape with a l/e value of 56 nm. A very small number of nonradiative recombination centers are considered to be generated, because the integrated PL intensity including both emission peaks at 1.490 eV and at 1.516 eV is the same before and after the RIE. The surface recombination rate of the sidewall formed by the RIE is almost the same as that of the wet-etched surface. This low-damage etching has been applied to fabricate ultra-fine GaAs patterns to provide a nanometer-scale ridge structure with a cross-section 15-nm wide by 150-nm high. The low damage etching condition is also suitable for precise fabrication.

Fabrication of silicon nanowire based solar cells using TiO2/Al2O3 stack thin films

MRS Advances ◽  
2018 ◽  
Vol 3 (25) ◽  
pp. 1419-1426 ◽  
Author(s):  
Yasuyoshi Kurokawa ◽  
Ryota Nezasa ◽  
Shinya Kato ◽  
Hisashi Miyazaki ◽  
Isao Takahashi ◽  
...  
Keyword(s):  
Solar Cells ◽  
Surface Passivation ◽  
Silicon Nanowire ◽  
Surface Recombination ◽  
Single Layer ◽  
Minority Carrier Lifetime ◽  
Atomic Layer ◽  
Open Circuit ◽  
Surface Reflectance ◽  
Surface Recombination Rate

ABSTRACTTo improve conversion efficiency of silicon nanowire (SiNW) solar cells, it is very important to reduce the surface recombination rate on the surface of SiNWs, since SiNWs have a large surface area. We tried to cover SiNWs with aluminum oxide (Al2O3) and titanium oxide (TiO2) by atomic layer deposition (ALD), since Al2O3 grown by ALD provides an excellent level of surface passivation on silicon wafers and TiO2 has a higher refractive index than Al2O3, leading to the reduction of surface reflectance. The effective minority carrier lifetime in SiNW arrays embedded in a TiO2/Al2O3 stack layer of 94 μsec was obtained, which was comparable to an Al2O3 single layer. The surface reflectance of SiNW solar cells was drastically decreased below around 5% in all of the wavelength range using the Al2O3/TiO2/Al2O3 stack layer. Heterojunction SiNW solar cells with the structure of ITO/p-type hydrogenated amorphous silicon (a-Si:H)/n-type SiNWs embedded in Al2O3 and TiO2 stack layer for passivation/n-type a-Si:H/back electrode was fabricated, and a typical rectifying property and open-circuit voltage of 356 mV were successfully obtained.

CFD Simulation of Heating a Cu Pipe with a Safe H2/O2 Flame

2014 ◽  
Vol 611-612 ◽  
pp. 1553-1559
Author(s):  
Lars Kjäldman ◽  
Jouni Syrjänen
Keyword(s):  
Reasonable Agreement ◽  
Cfd Simulation ◽  
Temperature History ◽  
Measured Temperature ◽  
Dynamics Modeling ◽  
Computational Fluid Dynamics Modeling ◽  
History Of ◽  
Modeling And Experiments ◽  
Simulation Results ◽  
The Eu

As part of the EU/SME project SafeFlame (www.safeflameproject.eu ) the heating of a Cu pipe by a H2/O2 flame has been modeled and the results are compared to experiments. CFD (Computational Fluid Dynamics) modeling has been utilized to study the flow and combustion in the flame and the heat transfer from the flame to the pipe. The simulation results are compared with the measured temperature history of the pipe at different locations and with the visual flame. The influence of distance between the burner and the pipe and of using two opposite H2/O2 flames on the heating rate of the pipe has been investigated. Reasonable agreement between modeling and experiments has been obtained. The reasons for differences between modeling and experimental results are discussed.

Effect of Energy and Dose on Transient-Enhanced Diffusion and Defect Microstructure in Low Energy High Dose As+ Implanted Si

1996 ◽  
Vol 439 ◽  
Author(s):  
V. Krishnamoorthy ◽  
D. Venables ◽  
K. Moeller ◽  
K. S. Jones ◽  
B. Freer
Keyword(s):  
Point Defects ◽  
Surface Recombination ◽  
High Dose ◽  
Enhanced Diffusion ◽  
Projected Range ◽  
Diffusion Enhancement ◽  
Defect Microstructures ◽  
Dose Dependent ◽  
Higher Doses ◽  
Defect Microstructure

Abstract(001) CZ silicon wafers were implanted with arsenic (As+) at energies of 10–50keV to doses of 2x 1014 to 5x1015/cm2. All implants were amorphizing in nature. The samples were annealed at 700°C for 16hrs. The resultant defect microstructures were analyzed by XTEM and PTEM and the As profiles were analyzed by SIMS. The As profiles showed significantly enhanced diffusion in all of the annealed specimens. The diffusion enhancement was both energy and dose dependent. The lowest dose implant/annealed samples did not show As clustering which translated to a lack of defects at the projected range. At higher doses, however, projected range defects were clearly observed, presumably due to interstitials generated during As clustering. The extent of enhancement in diffusion and its relation to the defect microstructure is explained by a combination of factors including surface recombination of point defects, As precipitation, As clustering and end of range damage.

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