Analysis of Defects in Laser Annealed GaAs

1980 ◽  
Vol 2 ◽  
Author(s):  
John Fletcher ◽  
J. Narayan ◽  
D. H. Lowndes
Keyword(s):  
Laser Annealing ◽  
Laser Energy ◽  
Threshold Energy ◽  
High Dose ◽  
Surface Degradation ◽  
Plan View ◽  
Implantation Damage ◽  
Transmission Electron ◽  
Residual Damage ◽  
Good Agreement

ABSTRACTThe nature and depth distributions of residual damage in ion implanted and pulsed ruby laser annealed GaAs have been studied using both plan-view and cross-section transmission electron microscopy (TEM) specimens for high dose (1.0 × 1015 cm−2) Zn+, Se+ and Mg+ implants. It was found that laser energy densities above 0.36 J/cm2 were required to remove the implantation damage, this threshold energy density giving good agreement with that indicated by electrical activation measurements. Laser induced surface degradation of the GaAs was present even for energy densities as low as 0.25 J/cm2, and more severe damage, with the introduction of dislocations near the surface, was present for energy densities above 0.8 J/cm2. The use of thin SiO2 layers for encapsulation during laser annealing was found to substantially reduce this surface degradation.

Nonmelt Laser Annealing of 1 Kev Boron Implanted Silicon

2001 ◽  
Vol 669 ◽  
Author(s):  
Susan Earles ◽  
Mark Law ◽  
Kevin Jones ◽  
Somit Talwar ◽  
Sean Corcoran
Keyword(s):  
Laser Annealing ◽  
Laser Energy ◽  
High Dose ◽  
Ramp Rate ◽  
Dopant Activation ◽  
Pulsed Laser Annealing ◽  
Transmission Electron ◽  
Ultra Shallow Junctions ◽  
Defect Nucleation ◽  
Probe Measurements

ABSTRACTHeavily-doped, ultra-shallow junctions in boron implanted silicon using pulsed laser annealing have been created. Laser energy in the nonmelt regime has been supplied to the silicon surface at a ramp rategreater than 1010°C/sec. This rapid ramp rate will help decrease dopant diffusion while supplying enough energy to the surface to produce dopant activation. High-dose, non-amorphizing 1 keV, 1e15 ions/cm2 boron is used. Four-point probe measurements (FPP) show a drop in sheet resistance withnonmelt laser annealing (NLA) alone. Transmission electron microscopy (TEM) shows the NLA dramatically affects the defect nucleation resulting in fewer defects with post annealing. Hall mobility and secondary ion mass spectroscopy (SIMS) results are also shown.

The Effect of Implant Species on the Stability of Ion Implantation Damage

1988 ◽  
Vol 100 ◽  
Author(s):  
K. S. Jones ◽  
S. Prussin ◽  
D. Venables
Keyword(s):  
Solid Solubility ◽  
Chemical Species ◽  
Dislocation Loops ◽  
Cross Sectional ◽  
Plan View ◽  
Damage Category ◽  
Implantation Damage ◽  
Transmission Electron ◽  
Residual Damage ◽  
The Stability

ABSTRACTA systematic study of the effect of the chemical species, implanted into silicon, on the stability of the residual damage has been performed. Plan-view and cross-sectional transmission electron microscopy (TEM) studies show that the stability of the end of range damage (category II) defects upon annealing depends dramatically upon the implant species. This is exemplified by the a comparison of 69Ga and 72Ge implants in which a decrease in the dislocation density by over four orders is noted for 69Ga implants compared to 72Ge implants after identical annealing cycles. Additional comparisons of species with similar atomic masses indicate that this destabilizing influence on the dislocation loops by the implant species is related to exceeding the solid solubility of the implanted species. As a result of this dislocation loop destabilization effect complete elimination of the dislocation loops can be realized after relatively short thermal cycling. Evidence is presented indicating that the precipitates which form upon exceeding the solid solubility (category V defects) are dissolving during this enhanced defect dissolution process.

Photoluminescence of Pulsed Ruby Laser Annealed Crystalline and Ion Implanted GaAs

1981 ◽  
Vol 4 ◽  
Author(s):  
Douglas H. Lowndes ◽  
Bernard J. Feldman
Keyword(s):  
Radiative Recombination ◽  
Laser Annealing ◽  
Laser Energy ◽  
Pulsed Laser ◽  
High Dose ◽  
Pulsed Laser Annealing ◽  
Recombination Centers ◽  
Pl Intensity ◽  
P Type ◽  
Ion Implanted

ABSTRACTIn an effort to understand the origin of defects earlier found to be present in p–n junctions formed by pulsed laser annealing (PLA) of ion implanted (II) semiconducting GaAs, photoluminescence (PL) studies have been carried out. PL spectra have been obtained at 4K, 77K and 300K, for both n–and p–type GaAs, for laser energy densities 0 ≤ El ≤ 0.6 J/cm2. It is found that PLA of crystalline (c−) GaAs alters the PL spectrum and decreases the PL intensity, corresponding to an increase in density of non-radiative recombination centers with increasing El. The variation of PL intensity with El is found to be different for n– and p–type material. No PL is observed from high dose (1 or 5×1015 ions/cm2 ) Sior Zn-implanted GaAs, either before or after laser annealing. The results suggest that the ion implantation step is primarily responsible for formation of defects associated with the loss of radiative recombination, with pulsed annealing contributing only secondarily.

Formation of Sic, Si3N4 and SiO2 by High-Dose Ion Implantation and Laser Annealing

1980 ◽  
Vol 1 ◽  
Author(s):  
S.W. Chiang ◽  
Y.S. Liu ◽  
R.F. Reihl
Keyword(s):  
Ion Implantation ◽  
Polycrystalline Silicon ◽  
Laser Annealing ◽  
Pulsed Laser ◽  
High Dose ◽  
Pulsed Laser Annealing ◽  
Transmission Electron ◽  
A Cell ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

ABSTRACTHigh-dose ion implantation (1017 ions-cm−2) of C+, N+, and O+ at 50 KeV into silicon followed by pulsed laser annealing at 1.06 μm was studied. Formation of SiC, Si3N4, and SiO2 has been observed and investigated using Transmission Electron Microscopy (TEM) and Differential Fourier-Transform Infrared (FT-IR) Spectroscopy. Furthermore, in N+-implanted and laser-annealed silicon samples, we have observed a cell-like structure which has been identified to be spheroidal polycrystalline silicon formed by the rapid laser irradiation.

Defect Evolution During Laser Annealing

2006 ◽  
Vol 912 ◽  
Author(s):  
Susan B. Felch ◽  
Abhilash Mayur ◽  
Vijay Parihar ◽  
Faran Nouri ◽  
Kevin S. Jones ◽  
...  
Keyword(s):  
Laser Annealing ◽  
Annealing Temperature ◽  
Defect Density ◽  
Operating Conditions ◽  
Maximum Temperature ◽  
Plan View ◽  
Residual Defect ◽  
Low Temperature Annealing ◽  
Transmission Electron ◽  
Boron Dopant

AbstractImplementation of millisecond annealing requires the identification of the operating conditions for that technique which minimize the residual defects. In addition, possible combinations of low temperature annealing with millisecond annealing could result in minimal residual defects. The samples studied here were implanted with Ge+ pre-amorphization and boron dopant ions and were activated with a scanning laser annealing technique with maximum temperature dwell times of about one millisecond. The laser anneal conditions were varied, along with combinations of spike anneals. The annealed samples were analyzed by plan-view transmission electron microscopy (TEM) to measure the residual defect density and size. The effects of spike temperature, laser annealing temperature, and scan rate will be discussed.

Clustering Kinetics of Arsenic and Phosphorus in Laser Annealed Silicon

1985 ◽  
Vol 45 ◽  
Author(s):  
Josef Goetzlich
Keyword(s):  
Laser Annealing ◽  
Most Probable Number ◽  
High Dose ◽  
Second Phase ◽  
Probable Number ◽  
Relaxation Phase ◽  
Post Annealing ◽  
Residual Damage ◽  
Heavily Doped ◽  
Kinetics Of

ABSTRACTHigh-dose arsenic and phosphorus ion implanted silicon was annealed either by a CW CO2 or a pulsed Nd:YAG laser creating supersaturated dopant concentrations up to 3·1021 cm−3. The relaxation of these metastable electrically active atoms was investigated during thermal post-annealing at temperatures between 600 and 1000°C for times between 3 and 106 s. In heavily doped samples which contain residual damage after laser annealing, a very fast first relaxation phase is observed followed by a much slower second phase. In samples without residual damage only this second slower phase is seen. Carrier concentration profile measurements show that the saturation concentration after the relaxation depends only on temperature and corresponds to the concentration in thermal equilibrium. Using reaction kinetics a cluster model is proposed which demonstrates that in As doped layers the most probable number of As atoms in one cluster depends on temperature (4 As atoms at 700°C, 3 As atoms at 800 - 1000°C). In P doped layers the most probable clusters contain 3 P atoms at temperatures between 700 and 900°C.

Cross-sectional TEM and corrosion studies of Al and N implanted copper

1987 ◽  
Vol 93 ◽  
Author(s):  
E. Gerritsen ◽  
H. J. Ligthart ◽  
T. E. G. Deenen
Keyword(s):  
Electron Microscopy ◽  
High Dose ◽  
Copper Sulphide ◽  
Cross Sectional ◽  
Damage Layer ◽  
Implantation Damage ◽  
Transmission Electron ◽  
Corrosion Studies ◽  
Copper Single Crystals

ABSTRACTPoly- and single crystalline copper was implanted with aluminium and nitrogen at doses ranging from 1016 to 5 × 1017 at/cm2 and energies of 170 keV. The corrosion resistance of the implanted surfaces was tested by exposure to an H25-containing atmosphere. The amount of copper sulphide formed was measured by chrono potentiometric reduction. The amount of corrosion products was markedly reduced (up to a factor 50) by high dose implantations of aluminium. The microstructure of the implanted copper was examined by Transmission Electron Microscopy of cross-sectioned specimens. A deep damage layer far exceeding the ion range was observed. XTEM-pictures of aluminium implanted copper single crystals of various orientations suggest a channeling mechanism for this deep damage layer. In situ annealing of the specimens in the TEM showed that most of the implantation damage is removed at 600°C except for an array of dislocations at the end of the damage range.

Solid-Phase-Epitaxial Growth of Ion Implanted Silicon Using CW Laser and Electron Beam Annealing

1982 ◽  
Vol 13 ◽  
Author(s):  
J. Narayan ◽  
O. W. Holland ◽  
G. L. Olson
Keyword(s):  
Laser Annealing ◽  
Solid Phase ◽  
Furnace Annealing ◽  
Plan View ◽  
Dopant Segregation ◽  
Cw Laser ◽  
Retrograde Solubility ◽  
Section Electron ◽  
Residual Damage ◽  
Section Electron Microscopy

ABSTRACTThe nature of residual damage in As+, Sb+, and In+ implanted silicon after CW laser and e− beam annealing has been studied using plan-view and cross-section electron microscopy. Lattice location of implanted atoms and their concentrations were determined by Rutherford backscattering and channeling techniques. Maximum substitutional concentrations achieved by furnace annealing in a temperature range of 500–600°C have been previously reported [1] and greatly exceeded the retrograde solubility limits for all dopants studied. Higher temperatures and SPE growth rates characteristic of electron or cw laser annealing did not lead to greater incorporation of dopant within the lattice and often resulted in dopant precipitation. Dopant segregation at the surface was sometimes observed at higher temperatures.

Time-resolved optical studies of oxide-encapsulated silicon during pulsed laser melting

1988 ◽  
Vol 3 (3) ◽  
pp. 498-505 ◽  
Author(s):  
G. E. Jellison ◽  
D. H. Lowndes ◽  
J. W. Sharp
Keyword(s):  
Laser Annealing ◽  
Laser Energy ◽  
Threshold Energy ◽  
Pulsed Laser ◽  
Silicon Layer ◽  
Oxide Thickness ◽  
Time Resolved ◽  
Model Calculations ◽  
Near Surface ◽  
Surface Profiling

Nanosecond time-resolved reflectivity and ellipsometry experiments have been performed on (100) Si wafers encapsulated by 5.5–76.2 nm thick thermal oxides, using pulsed KrF (248 nm) laser energy densities sufficient to melt the Si beneath the oxide. Post-irradiation nulling ellipsometry, optical microphotography, and surface profiling measurements were carried out. It was found that the threshold energy density required to melt the Si varies with oxide thickness; this is explained primarily by the reflective properties of the oxide overlayer. The time-resolved reflectivity and ellipsometry measurements show that rippling of the SiO2 layer occurs on the 20–40 ns timescale and results in a decrease in specular reflectivity of the rippled silicon surface beneath. Optical model calculations suggest that pulsed laser annealing through a thick oxide layer results in a damaged near-surface silicon layer (∼ 30 nm thick); this layer contains defects that are probably responsible for the degraded performance of devices.

PULSED LASER ANNEALING OF ULTRA-SHALLOW JUNCTIONS IN SILICON–GERMANIUM

2010 ◽  
Vol 09 (04) ◽  
pp. 341-344
Author(s):  
L. S. TAN ◽  
J. Y. TAN ◽  
A. BEGUM ◽  
M. H. HONG ◽  
A. Y. DU ◽  
...  
Keyword(s):  
Silicon Germanium ◽  
Laser Annealing ◽  
Laser Energy ◽  
Process Window ◽  
Cross Sectional ◽  
Energy Fluence ◽  
Substrate Heating ◽  
Transmission Electron ◽  
The Difference ◽  
Ultra Shallow Junctions

The effect of laser energy fluence and substrate heating on the annealing of boron-implanted silicon–germanium epitaxial layers on silicon was investigated. By making use of the difference in the melting points of silicon–germanium and silicon, a process window in the laser energy fluence can be found such that the meltdepth was confined within the silicon–germanium. Pre-heating of the substrate to 300°C was done to reduce the laser fluence required and improve the surface morphology. Cross-sectional transmission electron microscopy showed that there were no end-of-range defects due to ion implantation at the silicon–germanium/silicon interface after the laser annealing.

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