Athermal annealing of phosphorus-ion-implanted silicon (original) (raw)
2000, Applied Physics Letters
A 1 cm 2 area in phosphorus-implanted silicon samples is annealed by irradiation of a much smaller 0.002 cm 2 area with a single laser pulse. Resistivity of the annealed region is uniform and similar to that measured after thermal annealing. Electrically activated donors did not diffuse into the sample and only slightly towards the sample surface. The process is 100% reproducible. We present evidence that the annealing is not caused by heat.
Related papers
Activation of Silicon Implanted with Phosphorus Atoms by Infrared Semiconductor Laser Annealing
Japanese Journal of Applied Physics, 2007
We activated silicon implanted with phosphorus atoms by infrared semiconductor laser annealing with a diamond-like carbon (DLC) optical absorption layer. The silicon samples implanted with phosphorus atoms at 10 and 70 keV with concentrations of 5 Â 10 14 , 1 Â 10 15 , and 2 Â 10 15 cm À2 were coated with 200-nm-thick DLC films. The samples were annealed by irradiation with a 940 nm continuous wave laser at 70 kW/cm 2 with a beam diameter of 180 mm. The laser beam was scanned using a moving stage at 3-20 cm/s, which gave an effective dwell time of 0.9-6.0 ms. The amorphized surface regions were recrystallized by laser annealing longer than 1.2 ms. The in-depth profile of phosphorus concentration hardly changed within 5 nm for laser annealing for 2.6 ms. The sheet resistance markedly decreased to 106 and 46 /sq for the samples implanted with phosphorus atoms at 10 and 70 keV by laser annealing at a dwell time of 2.6 ms, respectively. Phosphorus atoms were effectively activated with a carrier density near the phosphorus concentration for implantation at 70 keV. A low carrier generation rate was observed for implantation at 2 Â 10 15 cm À2 and 10 keV. An intermediate SiO 2 layer effectively blocked carbon incorporation to a level below 10 17 cm À3 .
Structural Changes in Phosphorus-Ion-Implanted Silicon
The structural changes produced in the near-surface region of single-crystal Si upon fabrication of delta back-surface-field devices were studied by x-ray diffraction in an offset-asymmetric geometry. The results demonstrate that implantation of 180-keV P+ ions into Si with a dose on the order of 1015 cm -2, followed by thermal annealing, allows buried amorphous Si layers to be produced. The structures thus prepared suffer a significant lattice strain perpendicular to the interface.
Focused phosphorus ion beam implantation into silicon
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1989
Phosphorus implantation into (100) silicon using a 32-keV focused ion beam is investigated from the standpoints of electrical properties and damage to the implanted layers. Phosphorus ions are extracted from the Pt-P-Sb alloy liguid-metal-ion source. Electrical properties are measured by isochronal annealing with Hall measurements and radiation damage is evaluated using a transmission electron microscope. Compared with the conventional implantation method, focused ion beam implantation causes heavier radiation damage and forms amorphous layers at a dose of 2 X lOI4 cm-* due to high current density.
Formation of a donor profile in silicon upon simultaneous implantation of phosphorus and sodium ions
Journal of Surface Investigation. X-ray, Synchrotron and Neutron Techniques, 2011
A four point probe method was used to study, as the layers were removed consecutively, the con centration distribution profiles of free electrons in high resistivity p Si with implanted P + and Na + ions. Anodic oxidation was used to remove layers at a depth of less than 1 µm, and polishing at larger depths. It was shown that the efficiency of diffusion doping of silicon with sodium is determined, to a large extent, by the ratio between the energies of P + and Na + ions. If the conditions are optimal, the efficiency of doping by simultaneous implantation of sodium and phosphorus ions is better (by a factor of 2.5 on the average) than that of doping with Na + ions only.
ESR studies of ion implanted phosphorus donors near the Si-SiO2 interface
2010
This work reports an ESR study of low energy, low fluence phosphorus ion implantation into silicon in order to observe the activation of phosphorus donors placed in close proximity to the Si-SiO2 interface. Electrical measurements, which were used to estimate donor activation levels, reported high implant recoveries when using 14 keV phosphorus ions however, it was not possible to correlate the intensity of the hyperfine resonance signal with the electrical measurements in the presence of an SiO2 interface due to donor state ionisation (i.e. compensation effects). Comparative measurements made on silicon with an H-passivated surface reported higher donor hyperfine signal levels consistent with lower surface defect densities at the interface.
Enhanced activation of implanted phosphorus in silicon under rf plasma treatment
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1989
of bound excitons is used to study the process of phosphorus activation in surface layers of implanted Al-SiO, -Si structures under rf nitrogen plasma treatment. It is shown that nonthermal process of phosphorus activation takes place at rf plasma treatment of silicon.
Damage created by high-current-density implants of phosphorus into ?100? and ?111? silicon wafers
Applied Physics A Solids and Surfaces, 1987
The damage left by high-current-density, ~9~tA/cm 2, implants of 120keV phosphorus into (100) and (111) silicon oriented substrates was investigated as a function of the fluence in the range 4x10~5-1.5x10~6/cm 2. The samples were analyzed by 2 MeV He + channeling and transmission electron microscopy. Initially a buried amorphous layer forms at low fluences until the wafer temperature saturates at-~ 450 ~ at a fluence of ~ 4.5 x 1015/cm 2. As the fluence is further increased ion-assisted regrowth of this initial buried amorphous layer takes place and is 2 to 2.5 times faster (with respect to ion fluence) for (100) substrates than for (111) substrates. At higher fluences, most of the residual damage is located at a depth equal to the sum of the projected range and of the straggling. In the regrown layers twins are found in both orientations, and in some cases a hexagonal silicon phase is present at high fluences. The results are compared with the ion assisted regrowth of amorphous layers at well defined temperatures in the 250~ ~ range.
Loading Preview
Sorry, preview is currently unavailable. You can download the paper by clicking the button above.