• International Journal of Safety
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• v.7 no.2
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• pp.27-30
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• 2008

In the 21st century, safety issues in the strained silicon industry, such as dislocation injection, should be carefully considered. This is because a microelectronic device usually contains sharp features (e.g., edges and corners) that may intensify stresses, inject dislocations into silicon, and ultimately cause the failure of the device. In this paper, critical residual stresses in various strained structures are calculated. It is confirmed that this model correctly predicts trends and the order of magnitude of critical residual stresses.

• Journal of the Semiconductor & Display Technology
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• v.17 no.4
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• pp.97-100
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• 2018

$NF_3$ Plasma etching of silicon was conducted by injecting only $NF_3$ gas into reactive ion etching. $NF_3$ Plasma etching was done in intermediate pressure. Silicon etching by $NF_3$ plasma in reactive ion etching was diagnosed through residual gas analyzer and optical emission spectroscopy. In plasma etching, optical emission spectroscopy is generally used to know what kinds of species in plasma. Also, residual gas analyzer is mainly to know the byproducts of etching process. Through experiments, the results of optical emission spectroscopy during silicon etching by $NF_3$ plasma was analyzed with connecting the results of etch rate of silicon and residual gas analyzer. It was confirmed that $NF_3$ plasma etching of silicon in reactive ion etching accords with the characteristic of reactive ion etching.

• Proceedings of the KIEE Conference
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• 2002.11a
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• pp.245-247
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• 2002

The paper represents the effects of the drive-in process parameters on the residual stress profile of the p+ silicon film. For the quantitative determination of the residual stress profiles, the test samples are doped via the fixed boron diffusion process and four types of the thermal oxidation processes and consecutively etched by the improved process. The residual stress measurement structures with the different thickness are simultaneously fabricated on the same silicon wafer. Since the residual stress profile is not uniform along the direction normal to the surface, the residual stress is assumed to be a polynomial function of the depth. All of the coefficients of the polynomial are determined from the deflections of cantilevers and the displacement of a rotating beam structure. As the drive-in temperature or the drive-in time increases, the boron concentration decreases and the magnitude of the average residual tensile stress decreases. Also, near the surface of the p+ film the residual tensile stress is transformed into the residual compressive stress and its magnitude increases.

• Proceedings of the KIEE Conference
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• 1998.07g
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• pp.2533-2535
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• 1998

In this paper, an effect of drive-in process temperature on the residual stress profile of the p+ silicon film has been investigated. The residual stress profile has been calculated as the fourth-order polynomials. All coefficients of the polynomials have been determined from the measurement of the vertical deflections of the p+ silicon cantilevers with various thickness and the tip displacement of the p+ silicon rotating beam. From the determination results of the residual stress profile, the average stress of the film thermally oxidized at 1000 $^{\circ}C$ is 15 MPa and that of the film oxidized at 1100 $^{\circ}C$ is 25 MPa. The profile of the residual stress through the high temperature drive-in process has a steeper gradient than the other case.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.9
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• pp.665-671
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• 1999

The paper represents the effects of the drive-in process parameters on the residual stress profile of the $p^+$ silicon film. Since the residual stress profile is notuniform along the direction normal to the surface, the residual stress is assumed to be a polynomial function of the depth. All the coefficients of the polynomial can be determined by measuring of the thicknesses and the deflections of cantilevers and the deflection of a rotating beam with a surface profiler meter and a microscope. As the drive-in temperature or the drive-in time increases, the boron concentration decreases and the magnitude of the average residual tensile stress decreases. Then, near the surface of the $p^+$ film the residual tensile stress is transformed into the residual compressive stress and its magnitude increases.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.593-595
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• 1995

X-Ray Diffraction method that gives direct information about the deformation of crystal lattice is used for the determination of profiles of the residual stress along the depth of heavily boron doped silicon. The residual stress distribution is obtained by XRD method as measuring the deformation of the front surface of the $p^+$ silicon layer fabricated through different etch time. It is determined that the compressive residual stress exists in the most region except the font surface.

• Journal of the Korean Ceramic Society
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• v.33 no.2
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• pp.127-134
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• 1996

The thermal residual stresses were estimated for brazed Si3N4/S.S.316 joints with Cu/Mo multi-interlayers using FEM, and their bending strengths at room temperature were measured for various interlayer configura-tions. The Cu, Mo multi-interlayer decreased the maximum residual stress in Si3N4 and caused the residual stress redistribution rsulting in the high residual stress at Mo interlayer. The stress distribution in the joints as well as the maximum residual stress in silicon nitride were found to be main factors for determining bending strengths and Weibull modulous of the joints. The bending strength of the brazed Si3N4/S.S.316 joints with specific Cu, Mo multi-interlayer system were found to be above 400 MPa.

• Journal of the Korean Ceramic Society
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• v.40 no.8
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• pp.770-776
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• 2003

#140 mesh and #600 mesh wheels were adopted to grind (111) and (100) oriented single crystalline silicon wafer and the grinding induced change of the surface integrity was investigated. For this purpose, microroughness, residual stress and phase transformation were analyzed for the ground surface. Microroughness was analyzed using AFM (Atomic Force Microscope) and crystal structure was analyzed using micro-Raman spectroscopy. The residual stress and phase transformation were also analyzed after thermal annealing in the air. As a result, microroughness of (111) wafer was larger than that of (100) wafer after grinding. It was observed using Raman spectrum that the silicon was transformed from diamond cubic Si-I to Si-III(body centered tetragonal) or Si-XII(rhombohedral). Residual stress relaxation was also shown in cavities which were produced after grinding. The thermal annealing was effective for the recovery of the silicon phase to the original phase and the residual stress relaxation.

• Journal of the Korean Ceramic Society
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• v.49 no.4
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• pp.301-307
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• 2012

SiAlON glasses are silicates or alumino-silicates, containing Mg, Ca, Y or rare earth (RE) ions as modifiers, in which nitrogen atoms substitute for oxygen atoms in the glass network. These glasses are found as intergranular films and at triple point junctions in silicon nitride ceramics and these grain boundary phases affect their fracture behaviour. This paper provides an overview of the preparation of M-SiAlON glasses and outlines the effects of composition on properties. As nitrogen substitutes for oxygen in SiAlON glasses, increases are observed in glass transition temperatures, viscosities, elastic moduli and microhardness. These property changes are compared with known effects of grain boundary glass chemistry in silicon nitride ceramics. Oxide sintering additives provide conditions for liquid phase sintering, reacting with surface silica on the $Si_3N_4$ particles and some of the nitride to form SiAlON liquid phases which on cooling remain as intergranular glasses. Thermal expansion mismatch between the grain boundary glass and the silicon nitride causes residual stresses in the material which can be determined from bulk SiAlON glass properties. The tensile residual stresses in the glass phase increase with increasing Y:Al ratio and this correlates with increasing fracture toughness as a result of easier debonding at the glass/${\beta}-Si_3N_4$ interface.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.24 no.5
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• pp.190-195
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• 2014

Because of the temperature gradient occurring during the growth of the ingot with directional solidification method, defects are generated and the residual stress is produced in the ingot. Changing the growth and cooling rate during the crystal growth process will be helpful for us to understand the defects and residual stress generation. The defects and residual stress can affect the properties of wafer. Generally, it was found that the size of grains and twin boundaries are smaller at the top area than at the bottom of the ingot regardless of growth and cooling condition. In addition to that, in the top area of silicon ingot, higher density of dislocation is observed to be present than in the bottom area of the silicon ingot. This observation implies that higher stress is imposed to the top area due to the faster cooling of silicon ingot after solidification process. In the ingot with slower growth rate, dislocation density was reduced and the TTV (Total Thickness Variation), saw mark, warp, and bow of wafer became lower. Therefore, optimum growth condition will help us to obtain high quality silicon ingot with low defect density and low residual stress.