Depth Profiles of High-energy Recoil Implantation of Boron into Silicon

2000 ◽  
Vol 610 ◽  
Author(s):  
Lin Shao ◽  
Xinming Lu ◽  
Jianyue Jin ◽  
Qinmian Li ◽  
Irene Rusakova ◽  
...  
Keyword(s):  
Ion Beam ◽  
High Energy ◽  
Implantation Energy ◽  
Strong Function ◽  
Recoil Implantation ◽  
Depth Profiles ◽  
Calculation Results ◽  
Energy Incident ◽  
Sims Analysis ◽  
Secondary Ion

AbstractWe have studied boron profiles by using the ion beam recoil implantation. A boron layer was first deposited onto Si, followed by irradiation with Si ions at various energies to knock the boron. Conventional belief is that the higher the implantation energy, the deeper the recoil profiles. While this is true for low-energy incident ions, we show here that the situation is reversed for incident Si ions of higher energy due to the fact that recoil probability at a given angle is a strong function of the energy of the primary projectile. Our experiments show that 500-keV high-energy recoil implantation produces a shallower B profile than lower-energy implantation such as 10 keV and 50 keV. The secondary-ion-massspectrometry (SIMS) analysis shows that the distribution of recoiled B atoms scattered by the energetic Si ions agrees with our calculation results. Sub-100 nm p+/n junctions have been realized with a 500-keV Si ion beam.

Accurate CsM+ SIMS Aluminum Dopant Profiling in SiC

2006 ◽  
Vol 527-529 ◽  
pp. 629-632 ◽  
Author(s):  
Howard E. Smith ◽  
Bang Hung Tsao ◽  
James D. Scofield
Keyword(s):  
Mass Spectrometry ◽  
Silicon Carbide ◽  
Concentration Profile ◽  
Secondary Ion Mass Spectrometry ◽  
Ion Beam ◽  
Dopant Profiling ◽  
Depth Profiles ◽  
Empirical Correction ◽  
The Matrix ◽  
Secondary Ion

The accuracy of Secondary Ion Mass Spectrometry (SIMS) depth profiles of aluminum (Al) dopant in silicon carbide (SiC) has been investigated. The Al SIMS profile differs in shape depending on whether it was obtained using a cesium (Cs+) or oxygen (O2 +) primary ion beam, and depends in the former case on which secondary ion is followed. The matrix signals indicate that the CsAl+ secondary ion yield changes during the Cs+ depth profile, probably because of the work function lowering due to the previously-implanted Al. These same matrix ion signals are used for a depth-dependent empirical correction to increase the accuracy of the Al concentration profile. The physics of these phenomena and the accuracy of the correction are discussed.

Accurate Modeling of Residual recoil-mixing during SIMS Measurements

2001 ◽  
Vol 669 ◽  
Author(s):  
Ming Hong Yang ◽  
Robert Odom
Keyword(s):  
Mass Spectrometry ◽  
Mass Transport ◽  
Response Function ◽  
Secondary Ion Mass Spectrometry ◽  
Ion Beam ◽  
Residual Effect ◽  
Analytical Technique ◽  
Depth Profiles ◽  
Secondary Ion ◽  
Powerful Analytical Technique

ABSTRACTSecondary ion mass spectrometry (SIMS) is an effective and powerful analytical technique, widely used in accurately determining dopant distributions (depth profiles). However, primary ion beam induced mass transport (ion mixing), especially the residual effect during SIMS profile measurements, greatly limits theaccuracy at nanometer depth resolutions by displacing and broadening the measured depth profile. In this paper, we present a simple deconvolution algorithm based on the general characteristics of the experimentally observed SIMS response function to reduce this broadening effect, thereby providing more accurate depth profiles. The results for several specific applications of this approach are presented and its strengths and limitations are discussed.

Improvement of the gas cluster ion beam-(GCIB)-based molecular secondary ion mass spectroscopy (SIMS) depth profile with O2+ cosputtering

The Analyst ◽  
2016 ◽  
Vol 141 (8) ◽  
pp. 2523-2533 ◽  
Author(s):  
Yi-Hsuan Chu ◽  
Hua-Yang Liao ◽  
Kang-Yi Lin ◽  
Hsun-Yun Chang ◽  
Wei-Lun Kao ◽  
...  
Keyword(s):  
Steady State ◽  
Depth Profile ◽  
Mass Spectroscopy ◽  
Ion Beam ◽  
Depth Profiles ◽  
Tof Sims ◽  
Cluster Ion ◽  
Gas Cluster Ion Beam ◽  
Secondary Ion ◽  
Sims Depth Profile

The Ar2500+ and O2+ cosputter in ToF-SIMS depth profiles retained >95% molecular ion intensity in the steady-state.

Nitrogen Ion Beam Irradiation on Amorphous Carbon

2007 ◽  
Vol 539-543 ◽  
pp. 3297-3302
Author(s):  
Yoshihisa Watanabe ◽  
Masami Aono ◽  
Nobuaki Kitazawa
Keyword(s):  
Thin Films ◽  
Amorphous Carbon ◽  
Carbon Nitride ◽  
Ion Irradiation ◽  
Ion Beam ◽  
High Energy ◽  
Beam Irradiation ◽  
Ion Beam Irradiation ◽  
Depth Profiles ◽  
Nitrogen Ion

Both bulk and thin film amorphous carbon were irradiated using a nitrogen ion beam and changes in surface roughness and composition after ion beam irradiation have been studied. Amorphous carbon thin films were prepared from toluene vapor using plasma enhanced chemical vapor deposition. Ion irradiation was performed at room temperature using a nitrogen ion beam and the ion beam energy was varied from 0.2 to 1.5 keV under the constant ion current density. Surface morphology was observed with atomic force microscopy (AFM). Depth profiles of nitrogen in the irradiated specimens were analyzed by X-ray photoelectron spectroscopy (XPS). AFM observations reveal that after the ion beam irradiation the surface of the bulk amorphous carbon becomes rough, while the surface of the amorphous carbon films becomes smooth. However, the notable difference in the surface roughness is hardly observed between low- and high-energy ion irradiation. From XPS studies, it is found that the nitrogen concentration near the surface increases after the ion irradiation for both bulk and thin films and irradiated nitrogen ions are combined with carbon, resulting in formation of carbon nitride layers. Depth profiles of nitrogen show that for the bulk specimen low-energy ion irradiation is more effective for the carbon nitride formation than high-energy ion irradiation, while for the thin films high-energy ions are implanted more deeply than low-energy ions.

Comparison of Low-and High-Voltage SEM Images of Beryllium

1990 ◽  
Vol 48 (1) ◽  
pp. 400-401
Author(s):  
C. W. Price
Keyword(s):  
High Voltage ◽  
Low Voltage ◽  
Signal To Noise Ratio ◽  
Ion Beam ◽  
Sem Images ◽  
Pumping System ◽  
Thin Oxide Film ◽  
Cryogenic Vacuum ◽  
Sims Analysis ◽  
Secondary Ion

Beryllium has a low secondary electron (SE) coefficient that produces a low signal-to-noise ratio, and in the past, this deficiency caused many workers to routinely coat beryllium with a high-Z material such as Au/Pd and examine the specimens at high voltage (HV). In principle, beryllium should be an ideal candidate for improved imaging with low voltage (LV), because its low atomic number permits excessive electron-beam penetration during HVSEM imaging — the use of LVSEM to analyze beryllium films was demonstrated previously. Unfortunately, low SE emission can seriously compromise LVSEM images from uncoated beryllium specimens, even with the improved LVSEM imaging capability of a SEM equipped with a field-emission gun (FESEM). This work demonstrates that some beryllium structures yield improved results with LVSEM imaging in a FESEM, particularly at low magnifications, while structures that require high magnification often yield better results with HVSEM.Specimens selected for this study include craters formed by a Cs+ ion beam in specimens that had been analyzed in an ion microanalyzer by secondary-ion mass spectroscopy (SIMS), machined surfaces, and fracture surfaces. SE images were obtained for this study with a Hitachi S-800 FESEM equipped with a cryogenic vacuum pumping system.Surface structure in a sputtered SIMS crater is shown at 2.0 kV in Fig. 1a and at 20 kV in Fig. 1b. This specimen was from commercial grade beryllium sheet. Prominent microtwins are visible in several grains in Fig. 1, and because of the excessive beam penetration at HV, the microtwins are better defined at LV in Fig. 1a than they are at HV in Fig. 1b. In addition, a fine faceted microstructure was formed by the ion beam that could be observed at intermediate magnifications, and it also was better defined at LV than at HV. The dark contamination film that is visible around some of the particles in Fig. 1a also is significant; this film was not apparent at voltages of 5 kV and higher, as demonstrated in Fig. 1b. SIMS ion images revealed that this material contained particles of several different compositions including carbides; since beryllium carbide hydrolyzes when exposed to moist air, the films are suspected to have formed by the decomposition of carbides when the specimen was removed from the ion microanalyzer after the SIMS analysis. This example demonstrates the excellent sensitivity of LVSEM to detect thin films, and it also suggests that contamination and the thin oxide film that forms on beryllium may impair SE imaging.

High Energy Ion Beam Mixing in Al2 O3

1983 ◽  
Vol 27 ◽  
Author(s):  
M. B. Lewis ◽  
C. J. Mchargue
Keyword(s):  
Elevated Temperatures ◽  
Ion Beam ◽  
High Energy ◽  
Binary Collision ◽  
Surface Layers ◽  
Ion Beam Mixing ◽  
Enhanced Diffusion ◽  
Depth Profiles ◽  
Metal Atoms ◽  
Radiation Enhanced Diffusion

ABSTRACTThe ion beam mixing technique has been employed to mix metal atoms into the surface layers of Al2O3. Ion beams of Fe+ and Zr+ in the 1 to 4 MeV energy range were used to irradiate Al2O3 specimens on the surfaces of which films of chromium or zirconium had been evaporated. Some specimens were irradiated at elevated temperatures of 873 or 1173 K. Rutherford backscattering (RBS) and channeling methods were used to measure the metal atom depth profiles near the surface. Analyses of the backscattering data included binary collision calculations using the codes TRIM and MARLOWE. The significance and limitations of high energy (>1 MeV) beams for ion beam mixing experiments is discussed. Evidence was found for radiation enhanced diffusion and/or solubility of zirconium and chromium in Al2O3 at 873 K.

Interaction Between Co and SiO2 During Ion-Beam Mixing and Rapid Thermal Annealing

1992 ◽  
Vol 260 ◽  
Author(s):  
C. Dehm ◽  
I. Kasko ◽  
E. P. Burte ◽  
H. Ryssel
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Annealing Temperature ◽  
Ion Beam ◽  
Ion Beam Mixing ◽  
Plan View ◽  
Implantation Energy ◽  
Transmission Electron ◽  
Co Concentration ◽  
Secondary Ion

ABSTRACTFor the application in self-aligned processes, it was supposed that CoSi2 could be superior to TiSi2, since, unlike Ti, a reaction between Co and SiO2 was not observed up to now. We studied the reaction of Co and SiO2 during ion-beam mixing and rapid thermal annealing (RTA). The influences of As and Ge implantation energy and dose were investigated in the range of 50 to 200 keV and 1–1014 to 5–1015 cm2. The annealing temperature was varied between 700° C and 1100°C.It could be demonstrated that the Co concentration in SiO2 rises with increasing Ge and As energy and dose up to values of 5·1015 cm2 compared to 2·1012 cm2 in unim-planted, annealed samples. The Co profiles in SiO2 were also studied by secondary ion mass spectroscopy (SIMS) and compared with Monte-Carlo simulations indicating pure ballistic mixing. Plan-view and cross-section transmission electron microscopy (TEM) were used to examine the SiO2 surface as well as the Co-SiO2 interface. These investigations revealed that ion-beam mixing with doses at or above 5·1014 cm2 and subsequent annealing does not damage the SiO2 unlike to unimplanted, annealed samples which show a rather severe structural change of the SiO2 surface increasing with rising annealing temperatures.

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