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The integration of excimer laser annealing (ELA) into the power MOS device technology is discussed. It is seen that ELA can be applied as a reliable, effective and advantageous process in semiconductor device fabrication.

Post-implantation annealing is typically used to remove structural defects and electrically activate implanted dopants in semiconductors. However, ion-induced defects and their interaction with dopants in group II oxide semiconductors are not fully understood. Here, we study defect evolution in the course of annealing in CdO and ZnO materials implanted with nitrogen which is one of the most promising candidates for p-type doping. The results of photoluminescence and ion channeling measurements revealed a striking difference in defect behavior between CdO and ZnO. In particular, the defect annealing in CdO exhibits a two stage behavior, the first stage accounting for efficient removal of point defects and small defect clusters, while the second one involves gradual disappearance of extended defects where the sample decomposition can play a role. In contrast, a strong reverse annealing occurs for ZnO with a maximum defect concentration around 900 °C. This effect occurs exclusively for nitrogen ions and is attributed to efficient growth of extended defects promoted by the presence of nitrogen. [ABSTRACT FROM AUTHOR]

Potentially, group-Ib elements (Cu, Ag, and Au) incorporated on Zn sites can be used for p-type doping of ZnO, and in the present paper, we use ion implantation to introduce Ag atoms in wurtzite ZnO single crystals. Monitoring the Li behavior, being a residual impurity in the crystals, as a tracer, we demonstrate that Zn interstitials assist the Ag diffusion and lead to Ag pile-up behind the implanted region after annealing above 800 °C. At even higher temperatures, a pronounced Ag loss from the sample surface occurs and concurrently the Ag atoms exhibit a trap-limited diffusion into the crystal bulk with an activation energy of ∼2.6 eV. The dominant traps are most likely Zn vacancies and substitutional Li atoms, yielding substitutional Ag atoms. In addition, formation of an anomalous multipeak Ag distribution in the implanted near-surface region after annealing can be attributed to local implantation-induced stoichiometry disturbances leading to trapping of the Ag atoms by O and Zn vacancies in the vicinity of the surface and in the end-of-range region, respectively. [ABSTRACT FROM AUTHOR]

Divacancy center generation in tin and or phosphorous doped silicon irradiated at room temperature by 2.0 MeV electrons was investigated using infrared absorption measurements and deep level transient spectroscopy. The results showed that divacancy generation was small in samples doped with tin, indicating that mobile monovacancies were present. On the other hand, divacancy generation in non tin-doped samples were not affected by monovacancies.

The effects of annealing on the optical properties and defect/dopant evolution in wurtzite (0001) ZnO single crystals implanted with Er ions are studied using a combination of Rutherford backscattering/channeling spectrometry and photoluminescence measurements. The results suggest a lattice recovery behavior dependent on ion dose and involving formation/evolution of an anomalous multipeak defect distribution, thermal stability of optically active Er complexes, and Er outdiffusion. An intermediate defect band occurring between the surface and ion-induced defects in the bulk is stable up to 900 °C and has a photoluminescence signature around 420 nm well corresponding to Zn interstitials. The optical activity of the Er atoms reaches a maximum after annealing at 700 °C but is not directly associated to the ideal Zn site configuration, since the Er substitutional fraction is maximal already in the as-implanted state. In its turn, annealing at temperatures above 700 °C leads to dissociation of the optically active Er complexes with subsequent outdiffusion of Er accompanied by the efficient lattice recovery. [ABSTRACT FROM AUTHOR]

Effects of high-temperature annealing on deep-level defects in a high-purity semi-insulating 4H silicon carbide substrate have been studied by employing current-voltage, capacitance-voltage, junction spectroscopy, and chemical impurity analysis measurements. Secondary ion mass spectrometry data reveal that the substrate contains boron with concentration in the mid 1015cm-3 range, while other impurities including nitrogen, aluminum, titanium, vanadium and chromium are below their detection limits (typically ~1014cm-3). Schottky barrier diodes fabricated on substrates annealed at 1400-1700 °C exhibit metal/p-type semiconductor behavior with a current rectification of up to 8 orders of magnitude at bias voltages of ±3V. With increasing annealing temperature, the series resistance of the Schottky barrier diodes decreases, and the net acceptor concentration in the substrates increases approaching the chemical boron content. Admittance spectroscopy results unveil the presence of shallow boron acceptors and deep-level defects with levels in lower half of the bandgap. After the 1400 °C annealing, the boron acceptor still remains strongly compensated at room temperature by deep donor-like levels located close to mid-gap. However, the latter decrease in concentration with increasing annealing temperature and after 1700 °C, the boron acceptor is essentially uncompensated. Hence, the deep donors are decisive for the semi-insulating properties of the substrates, and their thermal evolution limits the thermal budget for device processing. The origin of the deep donors is not well-established, but substantial evidence supporting an assignment to carbon vacancies is presented. [ABSTRACT FROM AUTHOR]

Research was conducted to examine the generation of vacancy-related point defects in low dose 1.3 MeV proton irradiated high purity silicon. The objective was to attempt to explore the ionization effect to determine a migration energy for the silicon self-interstitial at room temperature and below. An experimental value for the migration energy of the silicon interstitial is obtained by the use of the inverse dose rate effect. Results suggest that the interstitial motion is strongly enhanced by ionization effects occurring during the irradiation.

Al2O3 films have been deposited on n-type and p-type 4H-SiC by atomic layer chemical vapor deposition using trimethylaluminum as a precursor for aluminum and both H2O and O3 as an oxidant. After oxide deposition, annealing at different temperatures (800, 900, 1000 °C) in argon atmosphere for different durations (1, 2, 3 h) was performed. Bulk and interface properties of the oxide films were studied by capacitance-voltage, current-voltage, deep level transient spectroscopy, and thermally dielectric relaxation current (TDRC) measurements. The results reveal a decreasing flatband voltage with increasing annealing time, suggesting decrease of oxide charges and deep interface traps. After 3 h annealing at 1000 °C of the n-type samples, the flatband voltage is reduced to 6 V compared to a value in excess of 40 V for as-deposited samples. The TDRC measurements on annealed Al2O3/SiC (n-type) capacitors showed substantially different spectra relative to conventional SiO2/4H-SiC control samples; in the former ones no signal was recorded at temperatures less than 100 K, demonstrating a low density of shallow electron traps below the conduction band edge of 4H-SiC and hence a prospect of obtaining a high electron channel mobility in 4H-SiC metal-oxide-semiconductor field-effect devices with Al2O3 as gate dielectric. [ABSTRACT FROM AUTHOR]

The electrical characteristics and thermal stability of [Al.sub.2][O.sub.3] gate oxide layers deposited by atomic layer chemical vapor deposition (ALCVD) on 4H-SiC are described. The results have shown a decreasing flatband voltage with increasing annealing time, which has indicated decrease of oxide charges and deep interface traps.

Presents a study that examined the generation of intrinsic defect divacancy in silicon by energy particles. Background on the use of particle irradiation in the fabrication of semiconductor devices; Assessment of several techniques used in the study of divacancy; Analysis of the application of deep-level transient spectroscopy in the divacancies.