ION IMPLANTATION OF SILICON: II. ELECTRICAL EVALUATION USING HALL-EFFECT MEASUREMENTS

1967 ◽  
Vol 45 (12) ◽  
pp. 4073-4089 ◽  
Author(s):  
J. W. Mayer ◽  
O. J. Marsh ◽  
G. A. Shifrin ◽  
R. Baron

Hall-effect and sheet-resistivity measurements have been made on silicon samples implanted with Sb, Ga, and As ions at energies between 20 and 75 keV. These measurements determine the weighted average of the number Ns of carriers/cm2 and the carrier mobility in the implanted layer. A combination of Hall measurements and layer-removal techniques was used in some cases to obtain a more accurate value of the number of carriers/cm2 and the depth dependence of the carrier concentration and mobility.For Sb implantations both temperature and dose affect the anneal characteristics. Silicon samples implanted with Sb at room temperature exhibited n-type behavior following anneal at 300 °C, with little increase in Ns up to about 550 °C anneal temperatures. A 600 °C 10-minute anneal produced an order-of-magnitude increase in Ns. This change is associated with reordering of the amorphous layer created during room-temperature implantations. This amorphous layer is not produced in implantations made at temperatures above 450 °C. In low-dose (<1014/cm2) Sb implantations at 500 °C, Ns increased by a factor of 2 to 3 during anneal to 800 °C. In high-dose (>5 × 1014/cm2) Sb implantations, the carrier concentration exceeded the limit set by thermal equilibrium solubility of Sb in silicon. Under these conditions, annealing caused a decrease in Ns toward the value associated with the solubility.Such supersaturation effects were not observed in Ga and As implantations at 500 °C. Annealing to temperatures of 800–900 °C produced a one-to-two order-of-magnitude increase in the number of carriers/cm2. In Ga implantations annealed to 800–900 °C, the number of carriers/cm2 increased approximately linearly with increasing dose and then leveled off at a value near that expected from thermal solubility.The Rutherford-scattering data in the preceding paper indicates that the difference in implantation behavior between various ion species is due to differences in the relative number of ions on substitutional sites.

1985 ◽  
Vol 46 ◽  
Author(s):  
L.T. Parechanian ◽  
E.R. Weber ◽  
T.L. Hierl

AbstractThe simultaneous molecular beam epitaxy (MBE) growth of (100) and (110) GaAs/GaAsintentionally doped with Si(∼lE16/cm^3) was studied as a function of substrate temperature, arsenic overpressure, and epitaxial growth rate. The films wereanalyzed by scanning electron and optical microscopy, liquid helium photoluminescence (PL), and electronic characterization.For the (110) epitaxal layers, an increase in morphological defect density and degradation of PL signal was observed with a lowering of the substrate temperature from 570C. Capacitance-voltage (CV) and Hall Effect measurements yield room temperature donor concentrations for the (100) films of n∼l5/cm^3 while the (110) layers exhibit electron concentrations of n∼2El7/cm^3. Hall measurements at 77K on the (100) films show the expected mobility enhancement of Si donors, whereas the (110) epi layers become insulating or greatly compensated. This behavior suggests that room temperature conduction in the (110) films is due to a deeper donor partially compensated by an acceptor level whose concentration is of the same order of magnitude as that of any electrically active Si. Temperature dependent Hall effect indicates that the activation energy of the deeper donor level lies ∼290 meV from the conduction band. PL and Hall effect indicate that the better quality (110) material is grown by increasingthe arsenic flux during MBE growth. The nature of the defects involved with the growth process will be discussed.


1989 ◽  
Vol 162 ◽  
Author(s):  
K. Nishimura ◽  
K. Das ◽  
M. Iwase ◽  
J. T. Glass ◽  
K. Kobashi

ABSTRACTB doped diamond films were synthesized by microwave plasma CVD and electrical contacts were fabricated by R F sputtering. Rc was obtained for Pt, Ni, TaSi2, and Al asdeposited contacts at room temperature. Pt gave the minimum Rc and Al gave the maximum Rc of the metals investigated on films containing a carrier concentration of 5 × 1018/cm3. The minimum Rc, 8.6 × 10−4 Ω cm 2, was obtained on heavily B doped diamond films with a carrier concentration of 2.7 × 1020/cm3. After nnealing at 400 °C, the Rc of Pt contacts on B doped diamond films with a resistivity of 2×104 Ω1 cm decreased by approximately one order of magnitude.


2000 ◽  
Vol 610 ◽  
Author(s):  
Atsushi Murakoshi ◽  
Kyoichi Suguro ◽  
Masao Iwase ◽  
Mitsuhiro Tomita ◽  
Katsuya Okumura

AbstractWe propose a novel process module by using cryo-implantation and rapid thermal annealing (RTA). Boron or arsenic ions were implanted into a 8 inch (100) Si substrate which was cooled by using liquid nitrogen. The substrate temperature was controlled to be below at -160°C during ion implantation. It was found that an amorphous layer was formed by boron or arsenic implantation and the amorphous layer was completely recovered to a single crystal after annealing at 900°C for 30sec. No dislocation was observed in the implanted layer. It was also found that the thermal diffusion of boron was suppressed by cryo-implantation. PN junction depth was found to be about 10-20% shallower than that of room temperature implantation. These results suggest that transient enhanced diffusion of boron can be reduced by suppressing vacancy migration toward the surface during implantation. Cryo-implantation was found to be very effective in reducing defects and PN junction leakage was successfully reduced by one order of magnitude as compared with room temperature implantation.


1995 ◽  
Vol 378 ◽  
Author(s):  
J. C. Zolper ◽  
S. J. Pearton ◽  
C. R. Abernathy ◽  
C. B. Vartuli

AbstractWe report on the isolation properties of In0.75Al0.25N implanted with either N or O for several doses and post-implant anneal temperatures. Sheet resistance versus anneal temperature data are reported for the various implants with a maximum sheet resistance of <1×109 Ω/□ achieved for a high dose N-implant annealed at 600 or 700 °C and <5×108 Ω/□ achieved for a high dose O-implant annealed at 600 °C. These sheet resistances correspond to a greater than three order of magnitude increase over the as-grown values. The compensating defect level for the highest resistance N-implanted sample has an estimate ionization level 580 meV below the conduction band edge. Implant isolation of InAIN is also compared to oxygen implant isolation of InxGa1-xN — where only a 50 to 100 fold increase in sheet resistance is observed — to study the effect of Al in the isolation scheme.


1991 ◽  
Vol 224 ◽  
Author(s):  
John L. Altrip ◽  
Alan G.R. Evans ◽  
Nigel D. Young ◽  
John R. Logan

AbstractThe electrical activation of As implanted Si has been investigated on rapid thermal annealing timescales using sheet resistance, spreading resistance and Hall Effect techniques. For high dose implants (>1015 As cm-2) differential Hall Effect and spreading resistance profiles confirm the existence of a temperature dependent electrical solubility limit. However for low dose implants, annealing schedules chosen such that the electrical solubility limit is not exceeded reveal electrical deactivation which is not accounted for in the clustering theory. Hall Effect measurements performed as a function of temperature have enabled us to reveal directly electrically inactive As which is not observable at room temperature using standard electrical techniques. The results indicate that As atoms in Si introduce deep trapping levels within the bandgap which are responsible forremoving As from the conduction process at room temperature. This temperature activated process is characterized with an activation energy of 0.4eV.


2019 ◽  
Vol 219 ◽  
pp. 02002 ◽  
Author(s):  
C. Abel ◽  
N. J. Ayres ◽  
G. Ban ◽  
G. Bison ◽  
K. Bodek ◽  
...  

We present the new spectrometer for the neutron electric dipole moment (nEDM) search at the Paul Scherrer Institute (PSI), called n2EDM. The setup is at room temperature in vacuum using ultracold neutrons. n2EDM features a large UCN double storage chamber design with neutron transport adapted to the PSI UCN source. The design builds on experience gained from the previous apparatus operated at PSI until 2017. An order of magnitude increase in sensitivity is calculated for the new baseline setup based on scalable results from the previous apparatus, and the UCN source performance achieved in 2016.


1986 ◽  
Vol 75 ◽  
Author(s):  
A. E. Willner ◽  
D. V. Podlesnik ◽  
H. Gilgen ◽  
R. M. Osgood

AbstractVery rapid room-temperature photochemical etching of n-type GaAs was achieved in aqueous hydrofluoric acid in conjunction with ultraviolet laser illumination. The etch rates of ˜500 μm/min represent an order of magnitude increase in etch rates over previously reported results for solutions that contained no hydrofluoric acid. Furthermore, incorporation of nitric acid into the hydrofluoric acid solution resulted in smooth etched surfaces thus allowing deep, waveguiding etching. This rapid process was used to etch deep, large-area structures in GaAs samples.


2003 ◽  
Vol 775 ◽  
Author(s):  
Tsuyoshi Kijima ◽  
Kenichi Iwanaga ◽  
Tomomi Hamasuna ◽  
Shinji Mohri ◽  
Mitsunori Yada ◽  
...  

AbstractEuropium-doped hexagonal-mesostructured and nanotubular yttrium oxides templated by dodecylsulfate species as well as surfactant free bulk oxides were synthesized by the homogeneous precipitation method. All the as grown nanostructured or bulk materials with amorphous or poorly crystalline frameworks showed weak luminescence bands at room temperature. On calcination at 1000°C these materials were converted into highly crystalline yttrium oxides, resulting in a total increase in intensity of all the bands by one order of magnitude. In the hexagonal-mesostructured system, the main band due to the 5D0-7F2 transition for the calcined phases showed a sharp but asymmetrical multiplet splitting indicating multiple Eu sites. Concentration quenching was found at a Eu content of 3 mol% or above for these phases. In contrast, the main emission for the calcined solids in the nanotubular system occurred as poorly resolved broad band and the intensity of the main band at higher Eu content was significantly enhanced compared with those for the other two systems.


2003 ◽  
Vol 775 ◽  
Author(s):  
Sung-Hwa Oh ◽  
Ju-Myung Song ◽  
Joon-Seop Kim ◽  
Hyang-Rim Oh ◽  
Jeong-A Yu

AbstractSolution behaviors of poly(styrene-co-sodium methacrylate) were studied by fluorescence spectroscopic methods using pyrene as a probe. The mol% of methacrylate was in the range 3.6–9.4. Water and N,N-dimethylforamide(DMF) mixture was used as a solvent (DMF/water = 0.2 mol %). The critical micelle (or aggregation) concentrations of ionomers and the partition coefficients of pyrene were obtained the temperature range 10–80°C. At room temperature, the values of CMCs (or CACs) were in the range 4.7 ×10-6 5.3 ×10-6 g/mL and we could not find any notable effect of the content of ionic repeat units within the experimental errors. Unlike CMCs, as the ion content increased, partitioning of pyrene between the hydrophobic aggregates and an aqueous media decreased from 1.5 ×105 to 9.4 ×104. As the temperature increased from 10 to 80 °C, the values of CMCs increased less than one order of magnitude. While, the partition coefficients of pyrene decreased one order of magnitude and the effect of the ion content became negligible.


2018 ◽  
Vol 31 (3) ◽  
pp. 20
Author(s):  
Sarmad M. M. Ali ◽  
Alia A.A. Shehab ◽  
Samir A. Maki

In this study, the ZnTe thin films were deposited on a glass substrate at a thickness of 400nm using vacuum evaporation technique (2×10-5mbar) at RT. Electrical conductivity and Hall effect measurements have been investigated as a function of variation of the doping ratios (3,5,7%) of the Cu element on the thin ZnTe films. The temperature range of (25-200°C) is to record the electrical conductivity values. The results of the films have two types of transport mechanisms of free carriers with two values of activation energy (Ea1, Ea2), expect 3% Cu. The activation energy (Ea1) increased from 29meV to 157meV before and after doping (Cu at 5%) respectively. The results of Hall effect measurements of ZnTe , ZnTe:Cu films show that all films were (p-type), the carrier concentration (1.1×1020 m-3) , Hall mobility (0.464m2/V.s) for pure ZnTe film, increases the carrier concentration (6.3×1021m-3) Hall mobility (2m2/V.s) for doping (Cu at 3%) film, but  decreases by increasing Cu concentration.


Sign in / Sign up

Export Citation Format

Share Document