Search

Czochralski silicon degenerately doped with boron at a low processing temperature is investigated to determine the generation mechanism of crystallographic defects. The defects were found to be of the a/2(110)-type elongated hexagonal and a/6(211)-type rhombus-shaped loops. The defects were identified using the transmission electron microscope. Numerous stacking faults of the type a/3(111)-type were observed although no precipitates were observed.

The morphological structure of oxide precipitates in boron-doped Czochralski silicon was investigated using transmission electron microscopy. The results showed that the oxide precipitates featured a disk-shaped structure with both (110)- and (111)-type habit planes. This indicated the possibility that localized reduction in the elastic moduli of silicon could facilitate the formation of disk-shaped precipitates on other planes.

Oxygen precipitation and defect formation in heavily doped Czochralski silicon which had undergone a two-step isochronal annealing process were investigated. The results showed that in boron-doped silicon, two defect density peaks were present. When the carbon or boron had a tetrahedral covalent radius smaller than silicon, doping reduced the peak height and resulted in a third characteristic peak.

Transmission electron microscopic studies reveal the precipitation of metal silicides in as-grown Czochralski silicon crystals with 3d transition metals as contaminants. Crystals grown under slow cooling conditions exhibit preferential copper silicide precipitation. Supersaturation of silicon interstitials leads to coprecipitation of titanium and silicon interstitials. Silicon lattices can have the incorporated 3d transition-metals as isolated interstitial impurities or precipitate the metal atoms at the crystal lattice defects through silicide formation.

D-defect dissolution in P- and N-type Czochralski silicon during high temperature annealing does not depend on D defect density in as-received wafers and doping impurity type. Silicon matrix-based vacancy undersaturation causes D-defect dissolution.

Oxygen distribution in a thin epitaxial silicon layer and substrate wafers heavily doped with boron and antimony was investigated using secondary ion mass spectrometry. The results showed that oxygen outdiffusion during the epitaxial deposition process was not affected by boron- or antimony-doping. The plane at which the oxygen concentration was half that of the bulk oxygen concentration did not remain at the epitaxial layer/substrate interface.

Presents a quantitative model for an interaction between extended dislocation loops and impurities in Czochralski silicon based upon the photoluminescence analysis. Interaction between the dislocations and impurities; Role of the dissolved oxygen concentration on the D-line luminescence; Preparation of samples used in the experiment.

Studies the effects of the denudation anneal on the precipitate dissolution and defect-free zone formation in Czochralski silicon wafers after a three-step internal gettering anneal. Precipitation of excess oxygen during the crystal growth cooling period; Effect of the denudational anneal on the precipitate dissolution in the subsurface region; Discussion on the results of the study.

Describes an experimental method to estimate a diffusivity of silicon interstitials. Importance of point defects in the process of physics of impurity diffusion; Estimation of silicon interstitial diffusivity at high temperature; Discussion on the result of the study.

Characterizes epitaxial silicon wafers and substrate interface using pulsed metal-oxide-semiconductor capacitance-time transient analysis. Observation of improvements in the generation lifetime of the epitaxial layer of samples which receive nucleation anneal; Effect of nucleation anneal on recombination lifetime; Electronic effects responsible for the limitation of the recombination lifetime of thin epitaxial layer.

Studies the influence of the preepitaxial annealing and polycrystalline silicon deposition processes on oxygen precipitation and internal gettering in N/N+(100) epitaxial silicon wafers. Major cause of low production yield and poor integrated circuit device performance; Use of the internal gettering process utilizing the thermal defects associated with oxide precipitates; Characterization of two types of bulk microdefects using the scanning electron microscope.

Presents information on a study which preannealed substrate wafers used for fabrication of epitaxial silicon wafers heavily doped with antimony prior to epitaxial deposition. Comparison between precipitation in post-epitaxial annealed and nonannealed wafers; Types of bulk microdefects observed on the cleaved surface of samples after the Wright etch; Reexamination of etched samples under the scanning electron microscope.

Deals with a study which investigated the effect of carbon and tin on the oxygen precipitation and the thermal donor formation in Czochralski-grown silicon after an extended isochronal anneal. Oxygen precipitation on doped silicon; Role of the lattice strain in oxygen precipitation.

Studies the oxygen diffusion in carbon-doped silicon. Effects of oxygen precipitation on silicon wafers; Details on the experiment; Discussion on the results of the study.

Examines the effect of high-temperature annealing on the dissolution of D-defects in n-type Czochralski silicon. Production of D-defects by vacancy aggregation; Influence of D-defects on the gate oxide integrity of metal-oxide semiconductor devices; Improvement of integrated circuits for the removal of D-defects.

Photoluminescence at the photon energies of 0.808 and 0.874 eV was observed in silicon containing a high concentration of carbon after a two-step isochronal anneal. The annealing sequence consisted of a low-temperature isochronal anneal and a 1050 °C anneal, respectively. The observed luminescence had the photon energies corresponding to those of the D lines which are known to arise from the interstitial-type dislocation loops. In silicon containing a high concentration of carbon, a formation of the dislocation loops was hypothesized to occur via a condensation of the excess silicon interstitials, originated from the agglomerates of interstitial carbons. [ABSTRACT FROM AUTHOR]

The outdiffusion profiles of oxygen from (100) Czochralski-grown silicon, doped with antimony at different doping concentrations ranging between 6×1015 and 3×1018 atoms/cm3, were measured using secondary ion mass spectrometry. From the oxygen depth profiles the diffusivity of 16O was determined. It was found that the outdiffusion of 16O was not influenced by the antimony doping concentration. The diffusivity of oxygen at 1100 °C, as determined in this work, was 1.1×10-10 cm2/s. This result agrees well with the previous literature values, D=0.07 exp(-2.44/kT), which were determined in float-zone silicon. [ABSTRACT FROM AUTHOR]