• 전기의세계
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• 제30권4호
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• pp.227-230
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• 1981

The variation of sheet resistance and the reduction of masking oxide thickness with the flow rate of nitrogen gas has been measured in Boron predeposition process with Planar Diffusion source, BN-975. At 900.deg. C, the sheet resistance varied as much as 75% when the nitrogen flow rate was changed from 0.4 liters/min to 2.0 liters/min. At 975.deg. C, however, only 12% of sheet resistance variation was observed under the same flow rate change. The reduction of masking oxide thickness at 975.deg. C for a 5 min predeposition was 600 nm when the nitrogen flow rate was 0.4 liters/min. When the flow rate incresased to 1.9 liters/min, however, only 100nm of masking oxide was consumed in a similar predeposition process.

• The Korean Journal of Ceramics
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• 제6권3호
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• pp.245-249
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• 2000

Consolidation of amorphous powders is emerging as a route for synthesis of high strength composite materials. Diffusion processes necessary for consolidation are expected to be more rapid in amorphous state(SRO) than in the crystalline state(LRO). A new synthesis technique of exploiting polymeric ceramic precursors(polysilazane and polyborosilazane) is derived for Si$_3$N$_4$/SiC and boron-modified nanocomposites for extremely high temperature applications up to 200$0^{\circ}C$. The characterization methods include thermal analysis of DTA, and XRD, NMR, TEM, after pyrolysis, as a function of time and temperature.

• Korean Journal of Materials Research
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• 제15권11호
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• pp.735-740
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• 2005

The phase transformation of Ni-B diffusion barrier by Cu diffusion was studied. The Ni-B diffusion barrier, thickness of 10(Inn, was electrolessly deposited on the electroplated Cu interconnect. The specimens were annealed either in Ar atmosphere or in $H_2$ atmosphere from $300^{\circ}C\;to\;800^{\circ}C$ for 30min, respectively. Although the Ni-B coated specimens showed the decomposition of $Ni_3B$ above $400^{\circ}C$ in both Ar atmosphere and $H_2$ atmosphere, Ni-B powders did not show the decomposition of $Ni_3B$. The $Ni_3B$ was decomposed to Ni and B in hi atmospherr: and the metallic Ni formed the solid solution with Cu and the free B was oxidized to $B_2O_3$. However, both the boron hydride and free B were not observed in the diffusion barrier after the annealing in $H_2$ atmos There. These results revealed that the decomposition of $Ni_3B$ by Cu made the Cu diffusion continued toward the Ni-B diffusion barrier.

• Korean Journal of Materials Research
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• 제1권3호
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• pp.125-131
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• 1991

Boron penetration phenomenon of $p^{+}$ silicon gate with as-deposited amorphous or polycrystalline Si upon high temperature annealing was investigated using high frequency C-V (Capacitance-Volt-age) analysis, CCST(Constant Current Stress Test), TEM(Transmission Electron Microscopy) and SIMS(Secondary Ion Mass Spectroscopy), C-V analysis showed that an as-deposited amorphous Si gate resulted in smaller positive shifts in flatband voltage compared wish a polycrystalline Si gate, thus giving 60-80 percent higher charge-to-breakdown of gate oxides. The reduced boron penetration of amorphous Si gate may be attributed to the fewer grain boundaries available for boron diffusion into the gate oxide and the shallower projected range of $BF_2$ implantation. The relation between electron trapping rate and flatband voltage shift was also discussed.

• Korean Chemical Engineering Research
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• 제55권6호
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• pp.861-867
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• 2017

In order to improve the capacity and cycling stability of Ni-rich NCA cathode materials for lithium ion batteries, the boron and cobalt were doped in commercial $Li_{1.06}Ni_{0.91}Co_{0.08}Al_{0.01}O_2$ (NCA) powders. Commercial NCA particles are mixed composites such as secondary particles of about $5{\mu}m$ and $12{\mu}m$, and the particle size was decreased by doping boron and cobalt. The initial discharge capacities of the boron and cobalt doped NCA-B and NCA-Co were found to be 214 mAh/g and 200 mAh/g, respectively, which are higher values than that of the raw NCA cathode material. In particular, NCA-Co exhibits the best discharge capacity of 157 mAh/g after 20 cycles, which is probably due to the enhanced diffusion of lithium ion by crystal growth along with the c-axis direction.

• Proceedings of the KWS Conference
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• 대한용접접합학회 2004년도 춘계 학술발표대회 개요집
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• pp.87-89
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• 2004

Brazing is an indispensable manufacturing technology for liquid rocket engine. In this study, for LRE injector, stainless steel 316L was used of base metal and Ni based MBF-20 of insert metal. The brazing and diffusion was carried out under various conditions. There are solid phase and. residual liquid phase in the brazed joint. With increment of holding time, the amount of solid phase increased and the elements of base metal and insert metal compositionally graded. Boron diffused from insert metal came into base metal and made boride with Cr and Mo at the brazed joint of base metal and insert metal.

• Journal of the Korean Institute of Telematics and Electronics
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• 제3권4호
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• pp.25-32
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• 1966

A silicon planar npn transistor has been fabricated. These transistors show three different characteristics, which are obtained with the variation of drive in time after the boron base diffusion. They are as follows:

• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.1084-1088
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• 1995

In this paper, an electrostatic plate resonator with four corrugated bridges and another with four flat ones have been fabricated and tested by the electrostatic actuation. The resonators consist of one rigid plate and four bridges. Boron diffusion process and anisotropic etch process with EPW are mainly used to fabricate the resonators. The dynamic characteristics of the fabricated resonators are obtained by measuring the velocity of the center of the rigid plate using a laser vibrometer. The results show that the deflection of the resonator with the corrugated bridges is larger than the resonator with the flat ones. It has been confirmed that the corrugated structure releases the residual tensile stress in the bridges resulted from the diffusion process.

• Journal of Welding and Joining
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• 제13권4호
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• pp.147-154
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• 1995

In order to study the bonding mechanism of Ni/B/Ni transient liquid phase bonding system, width of liquid layers were calculated, where in this system melting point of insert material(B) is higher than bonding temperature and melting point of base metal(Ni). Caclulated values were compared with experimental ones which were measured by bonding Ni/B/Ni system at 1433-1474K under vacuum atmosphere. As results, the width of initial liquid layer of Ni/B/Ni system was calculated as $W_{IL}$ = $W_{o}$[1 + {2.100..rho.$_{S/}$ ( $X_{3}$ + $X_{4}$)..rho.$_{Ni}$ }-.rho.$_{S/}$.rho. Ni/], and it was nearly same with experimental values. Maximum width of liquid layer, width of liquid layer during isothermal solidification and isothermal solidification time were calculated also.o.o.o.

• Journal of Welding and Joining
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• 제19권3호
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• pp.325-333
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• 2001

The effect of base metal grain size on isothermal solidification behavior of Ni-base superalloy, CMSX-2 during transient liquid phase (TLP) bonding was investigated employing MBF-80 insert metal. TLP-bonding of single crystal. coarse-grained and fine-grained CMSX-2 was carried out at 1373∼1548k for various holding time in vacuum. The eutectic width diminished linearly with the square root of holding time during isothermal solidification process for single crystal, coarse-grained and fine-grained base metals. The completion time for isothermal solidification decreased in the order ; single crystal, coarse-grained and fine-grained base metals. The difference of isothermal solidification rates produced when bonding the different base metals could be explained quantitatively by the effect of base metal grain boundaries on the apparent average diffusion coefficient of boron in CMSX-2.