Surface Damage In Silicon After 30 Kev Ga Fib Fabrication

2001

MRS Proceedings, 1995

New insight into damage formation in Si(100) during self-ion irradiation is gained from processing under extreme conditions. Dislocations form in the near-surface as a result of lattice relaxation in response to strain produced by precursor defects which are shown to be vacancy-type by positron analysis. A model to account for these defects and their distribution is presented. A novel technique is demonstrated which utilizes a subsequent implantation as a depth specific probe to manipulate the vacancy-type defects. Aspects of damage growth which emerge from the probe results are discussed.

Materials Letters, 2018

The exposure of sample to Focused Ion Beam leads to Ga-ion implantation, damage, material amorphisation, and the introduction of sources of residual stress; namely eigenstrain. In this study we employ synchrotron X-ray Reflectivity technique to characterise the amorphous layer generated in a single crystal Silicon sample by exposure to Ga-ion beam. The thickness, density and interface roughness of the amorphous layer were extracted from the analysis of the reflectivity curve. The outcome is compared with the eigenstrain profile evaluated from residual stress analysis by Molecular Dynamics and TEM imaging reported in the literature.

2000

Commercial focused ion beam (FIB) systems are commonly used to image integrated circuits (ICS) after device processing, especially in failure analysis applications. FIB systems are also often employed to repair faults in metal lines for otherwise functioning ICS, and are being evaluated for applications in film deposition and nanofabrication. A problem that is often seen in FIB imaging and repair

Current Applied Physics, 2003

The damage distributions in Si(1 0 0) surface after 1.0 and 0.5 keV Ar þ ion bombardment were studied using MEIS and Molecular dynamic (MD) simulation. The primary Ar þ ion beam direction was varied from surface normal to glancing angle. The MEIS results show that the damage thickness in 1.0 keV Ar ion bombardment is reduced from about 7.7 nm at surface normal incidence to 1.3 nm at the incident angle of 80°. However, the damage thickness in 0.5 keV Ar ion bombardment is reduced from 5.1 nm at surface normal incidence to 0.5 nm at the incident angle of 80°. The maximum atomic concentration of implanted Ar atoms after 1 keV ion bombardment is about 10.5 at% at the depth of 2.5 nm at surface normal incidence and about 2.0 at% at the depth of 1.2 nm at the incident angle of 80°. However, after 0.5 keV ion bombardments, it is 8.0 at% at the depth of 2.0 nm for surface normal incidence and the in-depth Ar distribution cannot be observable at the incident angle of 80°. MD simulation reproduced the damage distribution quantitatively.

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1987

To assist the production of layers 5-6/tm in thickness which are doped with gallium, MeV silicon implants have been used in conjunction with MeV gallium implants to determine whether the gallium will diffuse more readily in the damage created by the silicon atoms in gallium implanted substrates. This work requires that the damage and range profiles of thc two species be known. There are significant differences in the theoretical moments for the distributions depending on the approach being used. Profiles of the damage and range are compared to theoretical estimates in particular with those obtained from the Monte Carlo code TRIM. The damage is observed to anneal in the same manner as damage at much lower energies.

Journal of Applied Physics, 2018

The lateral damage induced by focused ion beam on silicon carbide was characterized using electrical scanning probe microscopy (SPM), namely, scanning spreading resistance microscopy and conductive atomic force microscopy (c-AFM). It is shown that the damage exceeds the purposely irradiated circles with a radius of 0.5 lm by several micrometres, up to 8 lm for the maximum applied ion dose of 10 18 cm À2. Obtained SPM results are critically compared with earlier findings on silicon. For doses above the amorphization threshold, in both cases, three different areas can be distinguished. The purposely irradiated area exhibits resistances smaller than the non-affected substrate. A second region with strongly increasing resistance and a maximum saturation value surrounds it. The third region shows the transition from maximum resistance to the base resistance of the unaffected substrate. It correlates to the transition from amorphized to defectrich to pristine crystalline substrate. Additionally, conventional transmission electron microscopy (TEM) and annular dark-field STEM were used to complement and explain the SPM results and get a further understanding of the defect spreading underneath the surface. Those measurements also show three different regions that correlate well with the regions observed from electrical SPM. TEM results further allow to explain observed differences in the electrical results for silicon and silicon carbide which are most prominent for ion doses above 3 Â 10 16 cm À2. Furthermore, the conventional approach to perform current-voltage measurements by c-AFM was critically reviewed and several improvements for measurement and analysis process were suggested that result in more reliable and impactful c-AFM data.

MRS Proceedings, 1985

Ion beam deposition (IBD), the process whereby magnetically analyzed ions are directly deposited on single crystal substrates, has been studied for 74Ge and 30 Si ions on Si(100) and Ge(100). The effects of sputtercleaning prior to deposition and substrate temperature during deposition were investigated. Three analytical techniques were systematically used to obtain information on the deposited films: (1) Rutherford backscattering combined with ion channeling, (2) cross-section TEM, and (3) Seeman-Bohlin X-ray diffraction.

Ultramicroscopy, 2001

All techniques employed in the preparation of samples for transmission electron microscopy (TEM) introduce or include artifacts that can degrade the images of the materials being studied. One significant cause of this image degradation is surface amorphization. The damaged top and bottom surface layers of TEM samples can obscure subtle detail, particularly at high magnification. Of the techniques typically used for TEM sample preparation of semiconducting materials, cleaving produces samples with the least surface amorphization, followed by low-angle ion milling, conventional ion milling, and focused ion beam (FIB) preparation. In this work, we present direct measurements of surface damage on silicon produced during TEM sample preparation utilizing these techniques. The thinnest damaged layer formed on a silicon surface was measured as 1.5 nm thick, while an optimized FIB sample preparation process results in the formation of a 22 nm thick damaged layer. Lattice images are obtainable from all samples.

MRS Proceedings, 1998

Subthreshold damage in p-type Si implanted and annealed at elevated temperature is characterized using deep level transient spectroscopy (DLTS) and transmission electron microscopy (TEM). P-type Si is implanted with Si, Ge and Sn with energies in the range of 4 to 8.5 MeV, doses from 7 × 1012to 1×1014cm−2and all annealed at 800°C for 15 min. For each implanted specie, DLTS spectra show a transition dose called threshold dose above which point defects transform in to extended defects. DLTS measurements have shown for the doses below threshold, a sharp peak, corresponding to the signature of point defects and for doses above threshold a broad peak indicating the presence of extended defects. This is found to be consistent with TEM analyses where no defects are seen for the doses below threshold and the presence of extended defects for the doses above threshold. This suggests a defect transformation regime where point defects present below threshold are acting like nucleating sites for...