Formation of buried Sb dopant profiles in silicon by pulsed laser epitaxy

1993 ◽  
Vol 8 (4) ◽  
pp. 841-846
Author(s):  
R.J. Carolissen ◽  
D.K. Knoesen ◽  
W.C. Sinke ◽  
R. Pretorius
Keyword(s):  
Laser Annealing ◽  
Pulsed Laser ◽  
Single Crystal Silicon ◽  
No Oxidation ◽  
Surface Layers ◽  
Crystal Silicon ◽  
State Diffusion ◽  
Degree Of Oxidation ◽  
Minimum Yield ◽  
Dopant Profiles

In this investigation buried Sb dopant profiles in single crystal silicon have been formed from evaporated layers using laser annealing. For irradiations carried out in air, severe oxidation of the surface layers inhibited epitaxy. Oxygen concentrations as high as 5 × 1017 atoms/cm2 (equivalent to about 105 nm SiO2) were measured. It was found that both the thin (less than 3 nm) Sb layer and the free volume in the a-Si, deposited by evaporation onto a cold substrate, need to be present for this degree of oxidation to take place. However, when silicon was evaporated onto a substrate heated to 350 °C, dense packing of the silicon atoms was obtained and even for irradiations in air good epitaxy (minimum yield of 7%) and no oxidation occurred. To form buried Sb profiles, laser energies only slightly higher than the threshold for epitaxy were used to prevent excessive spreading due to an increase in liquid state diffusion obtained at higher energies. Under these conditions the width of the buried Sb profile was typically about 120 nm, and up to 90% of the Sb atoms were found to occupy lattice sites.

Oxidation Effects During the Formation of Buried Sb Dopant Profiles in Silicon Using Pulsed Laser Epitaxy

1991 ◽  
Vol 235 ◽  
Author(s):  
Randall J. Carolissen ◽  
R. Pretorius
Keyword(s):  
Single Crystal ◽  
Laser Irradiation ◽  
Oxidation Kinetics ◽  
Ruby Laser ◽  
Pulsed Laser ◽  
Single Crystal Silicon ◽  
Heating Time ◽  
No Oxidation ◽  
Crystal Silicon ◽  
Oxygen Concentrations

ABSTRACTSevere oxidation inhibited epitaxy when buried Sb profiles in single crystal silicon were formed from evaporated layers irradiated in atmosphere with a pulsed Q-switched ruby laser. Oxygen concentrations as high as 5×1017atoms/cm2 (equivalent to 105nm SiO2) were measured. However, structures prepared without the Sb layer and irradiated under identical conditions, showed no oxidation. Oxidation of Sb as a source of the measured oxygen was ruled out, while the total heating time during laser irradiation is so short (nano- to milliseconds) that normal oxidation kinetics cannot account for the amount of SiO2 measured. Irradiations in vacuum and in a helium ambient showed that the oxygen responsible for these effects is supplied from the ambient in which irradiations are carried out. Also no oxidation was observed when structures, prepared on a substrate heated to 350°C, were irradiated in atmosphere. A model to account for these oxidation effects is proposed.

Thermally-Assisted Pulsed-Laser Annealing of SOS

1980 ◽  
Vol 1 ◽  
Author(s):  
Masayoshi Yamada ◽  
Ken-Ichi Yamazaki ◽  
Hisakazu Kotani ◽  
Keiichi Yamamoto ◽  
Kenji Abe
Keyword(s):  
Residual Strain ◽  
Room Temperature ◽  
Laser Annealing ◽  
Pulsed Laser ◽  
Single Crystal Silicon ◽  
Raman Shift ◽  
Crystal Silicon ◽  
Depolarization Factor ◽  
Pulsed Laser Annealing ◽  
Residual Strains

ABSTRACTThermally-assisted pulsed-laser annealing has been performed on ion-implanted silicon-on-sapphire(SOS) by irradiating Q-switched(20 nsec) ruby laser light during thermally heating. Raman scattering measurements have been made to estimate the residual strain of the annealed SOS. It was observed that Raman shift of SOS annealed in the temperature range of 400°C to 500°C was very close to that of single crystal silicon and the depolarization factor(the Raman intensity ratio of allowed z(xy)z to forbidden z(xx)z scattering configuration) was infinite, while Raman shift of SOS annealed at room temperature was shifted down to about 5 cm-1 and the depolarization factor was finite. It was found that the residual strain of SOS was relieved by the thermally-assisted pulsed-laser annealing, but the residual strain of SOS annealed at room temperature was inhomogeneous and attained to 7×10−3. The annealing temperature dependences of the residual strains were not explained well with a strictly thermal melting and recrystallization model in conjunction with the thermal expansion difference between silicon and sapphire, and suggested to need a new model.

Laser Annealing of GaP and GaAs in High-Pressure Argon Gas Ambients

1983 ◽  
Vol 23 ◽  
Author(s):  
Fumio Sato ◽  
Tadasu Sunada ◽  
Jun-ichi Chikawa
Keyword(s):  
Pressure Range ◽  
Laser Annealing ◽  
Diffusion Length ◽  
Pressure Effect ◽  
Pulsed Laser ◽  
Absorption Measurement ◽  
Surface Layers ◽  
Argon Gas ◽  
Optical Absorption Measurement ◽  
Pulsed Laser Annealing

ABSTRACTPulsed laser annealing has been made for Te or Znimplanted GaP and Si-implanted GaAs in argon gas atmospheres in a pressure range of 1 to 1000 bar. Optical absorption measurement indicates that pulse annealing under pressures higher than 300 bar forms surface layers with a high crystallinity without appreciable evaporation of P or As. This pressure effect is discussed from the viewpoint of diffusion length of evaporated atoms during the annealing time.

Growth and Characterization of Titanium Nitride Nanowires on Silicon Substrate Using Pulsed Laser Deposition Method for Biological Applications

2013 ◽  
Author(s):  
Seyram Gbordzoe ◽  
K. Mensah-Darkwa ◽  
Ram Gupta ◽  
Dhananjay Kumar
Keyword(s):  
Titanium Nitride ◽  
Pulsed Laser Deposition ◽  
Silicon Substrate ◽  
Laser Energy ◽  
Pulsed Laser ◽  
Single Crystal Silicon ◽  
Laser Deposition ◽  
Sem Images ◽  
Crystal Silicon

The present work reports on the growth and characterization of titanium nitride (TiN) nanowires on silicon substrate using a pulsed laser deposition (PLD) method. The TiN nanowires were grown on single crystal silicon substrate with (100) and (111) orientations at a range of substrate temperatures and under both nitrogen ambient and vacuum. The different orientation of silicon was chosen to see the effect of the substrate orientation on the growth of TiN nanowires. The laser energy entering the vacuum chamber to impinge the TiN target for nanowire deposition was varied from 70 to 80 mJ. The TiN nanowires samples were characterized using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). The diameter of the nanowires was observed to increase from 25 nm to 40 nm with an increase in laser beam energy entering the chamber. The shape and orientation of the nanowires was observed to be the same for (100) and (111) oriented silicon substrates as observed in SEM images. Corrosion tests were also conducted on the TiN nanowires.

Microstructural Control of Amorphous Silicon Films Crystallized using an Excimer Laser

1997 ◽  
Vol 472 ◽  
Author(s):  
J.W. Viatella ◽  
R.K. Singh
Keyword(s):  
Laser Annealing ◽  
Laser Energy ◽  
Single Crystal Silicon ◽  
Silicon Films ◽  
Crystal Silicon ◽  
Intimate Contact ◽  
Fine Grained ◽  
Silicon Thin Films ◽  
Fine Mesh ◽  
Microstructural Control

ABSTRACTThe results of experiments using two techniques for microstructural control of laser-annealed silicon thin films on SiO2 substrates are given. In the first set, photolithographically fabricated single-crystal silicon seed wafers in intimate contact with the silicon films are used to show that it is possible to control nucleation location during laser annealing. Laser energy density was varied from 250–450 mJ/cm2 and the resultant microstructure was characterized using transmission electron microscopy (TEM). It was found to consist of four distinct regions. Areas adjacent to the seed consisted of grains with dimensions ∼ 0.5 μm. The surrounding region consisted of larger (∼ 1 μm) rectangular grains. A third region was observed sporadically and consisted of large (∼ 1.5 μm) rectangular grains adjacent to the latter region. The fourth region occurred several microns away from the contact and consisted of a fine-grained microstructure. In the second set, fine mesh (19 μm) masks were used to selectively crystallize regions in laser-annealed films. The resultant microstructure was characterized using TEM and was found to consist of large (∼ 1.5 μm) edge grains with smaller (∼ 0.8 μm) grains just inside of the edge grains. A theoretical discussion is presented to explain the observed phenomena in both experiment sets.

Double-Crystal X-ray Diffraction Studies of Si ion-Implanted and Pulsed Laser-Annealed GaAs

1990 ◽  
Vol 34 ◽  
pp. 531-541
Author(s):  
P. M. Adams ◽  
J. F. Knudsen ◽  
R. C. Bowman
Keyword(s):  
Ion Implantation ◽  
Laser Annealing ◽  
Pulsed Laser ◽  
Thermal Treatments ◽  
X Ray Diffraction ◽  
Surface Layers ◽  
Double Crystal ◽  
X Ray ◽  
Pulsed Laser Annealing ◽  
Microelectronic Devices

Ion-implantation has many applications in the fabrication and processing of microelectronic devices from semiconductors, but thermal treatments are required to remove defects produced by the implant and to electrically activate dopants. Recently, pulsed laser annealing has been used to activate surface layers of GaAs that have been heavily doped with 28Si+ by ion implantation, and carrier concentrations of > 1 x 1019 cm-3 have been achieved (Ref. 1). Double-crystal x-ray diffraction techniques are very sensitive to strains and defects in single crystals and provide a means for characterizing and quantifying the damage produced by ion-implantation and the subsequent relief of damage by pulsed laser annealing.

Raman Scattering Characterization of Bonding Defects in Silicon

1980 ◽  
Vol 2 ◽  
Author(s):  
Raphael Tsu
Keyword(s):  
Energy Density ◽  
Raman Scattering ◽  
Single Crystal ◽  
Pulsed Laser ◽  
Single Crystal Silicon ◽  
Raman Peak ◽  
Crystal Silicon ◽  
Amorphous Si ◽  
Phonon Structure

ABSTRACTRaman scattering is used for the characterization of defects in Si. Damage is produced in single crystal silicon by ion-implantation of As and Si. The phonon structure of the damaged layer is that of the typical amorphous Si. After irradiation by pulsed laser(10ns,532nm) at energy density of approximately 0.1J/cm2, a Raman peak appears at a frequency between 508 cm−1 and 517 cm−1 depending on implant dosage. The higher the implant dosage, the lower is the frequency. We explain this in terms of the residual bonding defects caused by the presence of extraneous atoms such as oxygen. On the other hand, irradiation at an energy density in excess of 0.5 J/cm2, a Raman peak appears at a frequency close to that of the single crystal except for small shifts due to Fano-shift. For implant dosage in excess of 4×1016 As/cm2 , we have found additional peaks at 222 cm−1 and 267 cm−1 which are close to the metallic arsenic modes indicating the presence of arsenic clusters.

scholarly journals Nanosecond Pulsed Laser Processing of Ion Implanted Single Crystal Silicon Carbide Thin Layers

2014 ◽  
Vol 56 ◽  
pp. 933-943 ◽  
Author(s):  
Tuğrul Özel ◽  
Thanongsak Thepsonthi ◽  
Voshadhi P. Amarasinghe ◽  
George K. Celler
Keyword(s):  
Silicon Carbide ◽  
Single Crystal ◽  
Laser Processing ◽  
Pulsed Laser ◽  
Single Crystal Silicon ◽  
Thin Layers ◽  
Crystal Silicon ◽  
Nanosecond Pulsed Laser ◽  
Pulsed Laser Processing ◽  
Ion Implanted
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