Characterization of Crystal Quality by Crystal Originated Particle Delineation and the Impact on the Silicon Wafer Surface

Abstract

Characterization of Si wafers by delineation of crystal originated particles (COP) provides insight into size and radial distribution of crystal related defects. A good correlation of the COP densities with gate oxide integrity and flow pattern defect densities is observed. The density and size distribution of COP in Czochralski Si ingots can be modified by the pulling rate and the cooling conditions of the crystal and is further influenced by high doping concentrations. The COP densities are comparable on wafers with (100) Si and (111) Si orientation as well as on p-and n-type wafers with moderate doping level. No COP are found on float zone (FZ) and on epitaxially grown wafers. Crystal defects are also delineated by chemomechanical polishing and can be detected on the wafer surface as light point defects (LPD). LPD densities, however, do not necessarily correlate with the corresponding COP densities after SC1 treatment and do not reflect the quality of the crystals because polishing delineates only part of the larger crystal defects to a size which is above the detection limits of commercially available scanning surface inspection systems. High temperature annealing results in reduction of defect sizes and partial dissolution of COP. Investigations of FZ and oxygen doped float zone indicate that oxygen is participating in the formation of COP.

Advancements in semiconductor core optical fiber

“…Subsequent, though un-published, X-ray diffraction analysis clearly shows the limited presence of small Si 3 N 4 precipitates in the silicon core optical fibers. Nitrogen is occasionally doped into silicon in order to reduce defect size [44,45]. The Si 3 N 4 precipitates would also contribute to the Rayleigh scattering, though with a different dependence than SiO 2 precipitates, due to a differing refractive index contrast and size distribution.…”

Surface Formation of Single Silicon Wafer Polished with Nano-sized Al2O3 Powders

“…This indicates that there is some new substance formed on the surface of the wafer and the new substance may be the soft corrosion layer. Removal of silicon during CMP is explained by an attack of OH − to silicon atoms catalyzing the corrosive reaction of H 2 O resulting in cleavage of silicon bonds [5,32]. The chemical equation is the following: If SiO 3 2− in the slurry can not be removed immediately, SiO 3 2− can hydrolyze according to the following equation:…”

Nitrogen-Doped Czochralski Silicon Wafers as Materials for Conventional and Scaled Insulated Gate Bipolar Transistors

“…Kajiwara and S. Nishizawa are with Kyushu University, Kasuga-koen, Kasuga-shi, Fukuoka 816-8580, Japan. K. Eriguchi, K. Fusegawa, N. Mitsugi, S. Samata, K. Torigoe and M. Hourai are with Technology Division, Advanced Evaluation and Technology respectively, are required for manufacturing IGBTs [1]- [3]. For IGBTs with relatively low breakdown voltages in the range of 600-1200 V, silicon wafers cut from silicon single crystals with a diameter of 200 mm manufactured using the Czochralski technique (Cz-Si) with an oxygen concentration ([OI]) below 4.5 × 10 17 atoms cm −3 (JEIDA wafers) are typically used as these wafers are oxide precipitate-free after heat treatments [1].…”