Gas Phase Phosphorus Heavily-Doped FZ Silicon Thermal Field Design and Growth Method

2012 ◽  
Vol 430-432 ◽  
pp. 929-932
Author(s):  
Xue Nan Zhang ◽  
Jian Hong Li ◽  
Yu Tian Wang ◽  
Chang Xu Zhang ◽  
Chun Geng Yang ◽  
...  
Keyword(s):  
Gas Phase ◽  
Thermal Field ◽  
Cooling System ◽  
Silicon Crystal ◽  
Substrate Material ◽  
Low Oxygen ◽  
Float Zone ◽  
Growth Method ◽  
Resistivity Variation ◽  
Heavily Doped

This paper introduces the fabrication method of a kind of gas phase phosphorus heavily-doped float zone (FZ) silicon, including thermal field design (electromagnetic copper coil with double water cooling system). This method solves the problems during the pulling process of heavily-doped FZ silicon crystal of phosphorus doped. The gas phase phosphorus heavily-doped FZ silicon crystal using this methods with low oxygen content (less than 0.2ppma),low radial resistivity variation (less than 10%), low resistivity (the minimum of 0.002 ohm.cm), and is good to meet the transient voltage suppressor (TVS) for silicon substrate material requirements.

Morphology and development of flow-pattern defect with extended nonagitated Secco etching

1994 ◽  
Vol 52 ◽  
pp. 868-869
Author(s):  
Y. Pan
Keyword(s):  
Flow Pattern ◽  
Silicon Crystal ◽  
Gate Oxide ◽  
Crystal Growth Rate ◽  
Etch Depth ◽  
Force Microscopy ◽  
Etch Pit ◽  
Float Zone ◽  
Atomic Force ◽  
Multiple Step

The D defect, which causes the degradation of gate oxide integrities (GOI), can be revealed by Secco etching as flow pattern defect (FPD) in both float zone (FZ) and Czochralski (Cz) silicon crystal or as crystal originated particles (COP) by a multiple-step SC-1 cleaning process. By decreasing the crystal growth rate or high temperature annealing, the FPD density can be reduced, while the D defectsize increased. During the etching, the FPD surface density and etch pit size (FPD #1) increased withthe etch depth, while the wedge shaped contours do not change their positions and curvatures (FIG.l).In this paper, with atomic force microscopy (AFM), a simple model for FPD morphology by non-crystallographic preferential etching, such as Secco etching, was established.One sample wafer (FPD #2) was Secco etched with surface removed by 4 μm (FIG.2). The cross section view shows the FPD has a circular saucer pit and the wedge contours are actually the side surfaces of a terrace structure with very small slopes. Note that the scale in z direction is purposely enhanced in the AFM images. The pit dimensions are listed in TABLE 1.

Float-Zone silicon crystal growth at reduced RF frequencies

2012 ◽  
Vol 360 ◽  
pp. 43-46 ◽  
Author(s):  
H.-J. Rost ◽  
R. Menzel ◽  
A. Luedge ◽  
H. Riemann
Keyword(s):  
Crystal Growth ◽  
Silicon Crystal ◽  
Float Zone

Effect of O2 Partial Pressure on Post Annealed Ba2YCU3O7-δ Thin Films

1992 ◽  
Vol 275 ◽  
Author(s):  
Julia M. PhUlips ◽  
M. P. Siegal ◽  
S. Y. Hou ◽  
T. H. Tiefel ◽  
J. H. Marshall
Keyword(s):  
Partial Pressure ◽  
Film Growth ◽  
Epitaxial Films ◽  
Pinning Force ◽  
Low Oxygen ◽  
O2 Partial Pressure ◽  
Growth Method ◽  
Lower Temperature ◽  
The Relationship

ABSTRACTEpitaxial films of Ba2YCu3O7-δ (BYCO) as thin as 250 å A and with Jc's approaching those of the best in situ grown films can be formed by co-evaporating BaF2, Y, and Cu followed by a two-stage anneal. These results extend the work on films > 2000 Å thick by R. Feenstra et al. [J. Appl. Phys. 69, 6569 (1991)]. High quality films of these thicknesses become possible if low oxygen partial pressure [p(O2) = 4.3 Torr] is used during the high temperature portion cf the anneal (Ta). The BYCO melt line is the upper limit for Ta. The use of low p(O2) shifts the window for stable BYCO film growth to lower temperature, which allows the formation of smooth films with greater microstructural disorder than is found in films grown in p(O2) = 740 Torr at higher Ta. The best films annealed in p(O2)=4.3 Torr have Jc values a factor of four higher than do comparable films annealed in P2=740 Torr. The relationship between the T required to grow films with the strongest pinning force and p(O2) is log independent of growth method (in situ or situ) over a range of five orders of magnitude of P(O2).

Effect of oxygen on the formation of end-of-range disorder in implantation amorphized silicon

1991 ◽  
Vol 6 (8) ◽  
pp. 1695-1700 ◽  
Author(s):  
E. Lorenz ◽  
J. Gyulai ◽  
L. Frey ◽  
H. Ryssel ◽  
N.Q. Khanh
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Defect Structure ◽  
Defect Density ◽  
Low Oxygen ◽  
Continuous Layer ◽  
Float Zone ◽  
Order Of Magnitude ◽  
Visible Effect ◽  
Effect Of Oxygen

Formation of End-of-Range (EOR) disorder was studied in (100)-oriented silicon, when subjected to amorphization by implantation of Ge+ ions, followed by a 10 s Rapid Thermal Annealing (RTA) at 1050 °C. XTEM, RBS/channeling, and SIMS were used to analyze Czochralski grown (CZ) silicon wafers with oxygen concentrations of 6.5, 7.0, and 8.0 × 1017/cm3 and Float Zone (FZ) silicon, as “low oxygen” wafers. Amorphization on neighboring parts of the 4″ wafers was made either by 60 keV Ge+ implantation or by 110 keV Ge+ implantation and by sequential (60 keV + 110 keV) Ge+ implantation. Parts of each wafer were additionally implanted with 13 keV boron. In FZ silicon, no defects were found for 60 keV Ge+ implantation and RTA at 1050 °C. For 110 keV Ge+ and sequential (60 keV + 110 keV) Ge+ implantation in FZ-silicon the majority of the samples showed perfect annealing. Two wafers, however, subjected to sequential implantation still contained defects but with a defect density that was one order of magnitude lower than for CZ wafers. For one of them, not even a continuous layer of defects was formed. In contrast, CZ wafers contained defect bands, except for the 60 keV Ge+ implantation [in accord with the findings of Ozturk et al., IEEE Trans. on Electronic Dev. 35, 659 (1988)]. The presence of boron had no visible effect on the defect structure.

Doping of Diamond Crystals with a Dopant of P3N5

2012 ◽  
Vol 217-219 ◽  
pp. 96-100
Author(s):  
You Jin Zheng
Keyword(s):  
Photoelectron Spectroscopy ◽  
Diamond Crystal ◽  
Nitrogen Concentration ◽  
Diamond Growth ◽  
Ir Absorption ◽  
Xps Spectra ◽  
Diamond Crystals ◽  
Growth Method ◽  
Heavily Doped ◽  
Ppm Level

In this paper, a new dopant of P3N5 (phosphorus nitride) was doped into the diamond growth cell to grow diamond crystals by temperature gradient growth method (TGM) under high pressure and high temperature (HPHT). The experiments were performed at a fixed pressure of about 6.0 GPa and temperatures of 1600-1650 K. The gained diamond crystals were characterized by infrared (IR) absorption spectroscopy, micro-Raman spectroscopy and X-ray photoelectron spectroscopy (XPS), respectively. IR measurements demonstrated that, nitrogen atom was indeed doped into diamond crystals, and the diamond crystals with perfect shape containing nitrogen concentration ranging from 461 atomic parts per million (ppm) to 2186 atomic ppm were successfully synthesized. Nitrogen atoms present in diamond crystal were predominantly in isolated form accompanied by a small amount of nitrogen pairs. Micro-Raman spectra implied that crystalline quality deteriorated with nitrogen concentration gradually increased in diamond-growing environment. The XPS spectra revealed that only a few of phosphorus impurities about tens of ppm level were incorporated into a diamond crystal which was heavily doped with P3N5. This study will promote the application of doping diamonds in micro-electronics field and other fields.

scholarly journals Sensitivity to Oxygen of Nitrogenase Activity in Rhizobium Strain ANU289 of the Non-legume Parasponia (Ulmaceae)

1984 ◽  
Vol 37 (2) ◽  
pp. 31 ◽  
Author(s):  
S S Mohapatra ◽  
PM GresshoffA
Keyword(s):  
Carbon Source ◽  
Gas Phase ◽  
Cell Density ◽  
Oxygen Concentration ◽  
Oxygen Tension ◽  
Nitrogenase Activity ◽  
Rhizobium Strain ◽  
Low Oxygen ◽  
Liquid Cultures ◽  
Low Oxygen Tension

Nitrogenase activity can be detected in Rhizobium strain ANU289 of Parasponia in shaken liquid cultures. A combination of consistently low oxygen tension and appropriate cell density was found to be essential for rapid initiation and high specific rates (in the range of 50-60 nmoles of ethylene per milligram protein per hour). In the presence of succinate as carbon source and an oxygen concentration of 0�25% (v/v) in the gas phase, nitrogenase activity developed after incubation for 24 h. The requirement for an oxygen concentration in the range of O� 1 to 0�35% for derepression indicated a lack of any inherent tolerance to higher oxygen levels and thus suggests that plant-derived mechanisms are responsible for protection by oxygen in the nodule.

Biofiltration of dichlorobenzenes

2001 ◽  
Vol 44 (9) ◽  
pp. 287-293 ◽  
Author(s):  
F. Roberge ◽  
M.J. Gravel ◽  
L. Deschênes ◽  
C. Guy ◽  
R. Samson
Keyword(s):  
Gas Phase ◽  
Contaminated Soil ◽  
Cooling System ◽  
Ambient Air ◽  
Animal Manure ◽  
Full Scale ◽  
Peat Moss ◽  
Aerobic Treatment ◽  
Load Variations ◽  
System A

The use of air biofiltration for the degradation of dichlorobenzenes (1,2-DCB and 1,4-DCB) was studied at a refinery site. At this plant, 93 m3/h of contaminated groundwater, used in a cooling system and containing a maximum of 2 ppm of dichlorobenzenes, had to be treated. Stripping of the DCBs followed by biofiltration was selected as the most suitable technology to avoid volatilization in ambient air as expected with a wastewater aerobic treatment system. A stripper of 15 m height and 1.27 m diameter was designed as a first step treatment to volatilize DCBs with 3400 m3/h of air. Two full-scale biofilters of 70 m3 each were built and filled with 45 m3 of filtering media for the adsorption and biodegradation of the DCBs in the gas-phase. Filtering media was composed mainly of peat moss, with animal manure, wood chips and DCBs contaminated soil. Air to be treated was also contaminated with naphthalene. Laboratory tests showed an effective microbial activity in the contaminated soil and in the filtering media for DCBs degradation. Degradation of naphthalene induced slower degradation of DCBs. Full-scale operation was studied during four months. Water flow and DCBs content in the water entering the stripper were lower than expected with only 57 m3/h and a maximum concentration of only 240 ppb. Effective desorption was obtained in the stripper in the full-scale operation (more than 99% removal). Full-scale biofilters maintained a DCB concentration of less than 1 ppmv in the air outlet, but removal efficiency varied between 0 and 79% because of the low DCB inlet concentrations, load variations and sporadic naphthalene presence.

Seeded Growth of AlN on (0001)-Plane 6H-SiC Substrates

2009 ◽  
Vol 615-617 ◽  
pp. 983-986 ◽  
Author(s):  
Octavian Filip ◽  
Boris M. Epelbaum ◽  
Matthias Bickermann ◽  
Paul Heimann ◽  
S. Nagata ◽  
...  
Keyword(s):  
Growth Rates ◽  
Thermal Field ◽  
Substrate Material ◽  
Vapor Transport ◽  
Structural Quality ◽  
Seeded Growth ◽  
Large Area ◽  
Slow Cooling ◽  
High Power Microwave ◽  
Power Microwave

Aluminum nitride (AlN) is a promising substrate material for epitaxy of Al-rich III-nitrides to be employed, e.g., in deep-UV optoelectronic and high-power microwave devices. In this context, preparation of bulk AlN crystals by physical vapor transport (PVT) appears to be of most importance. In this work, seeded growth of AlN on (0001)-plane 6H-SiC substrates was investigated. SiC substrates with a diameter of 15 mm were used. AlN layers with thicknesses up to 3 mm were deposited at growth rates in the range of 10 to 40 μm/hour. Such templates provide large-area seeds, but they are often cracked, especially at thicknesses below 1mm. Besides cracks, other defects from the SiC seed propagate into the AlN layer and subsequently into the bulk AlN crystal. That is why, the aim of this work is to assess structural quality and defect content in thick AlN templates grown on (0001) plane SiC substrates. An optimum thickness-quality, the most appropriate growth stage for further use of the AlN template as a seed for subsequent PVT growth of bulk AlN growth, will be provided. We found that low growth rates mitigate crack propagation; slow cooling as well as optimization of the thermal field inside the crucible can prevent formation of new cracks after growth.

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