• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.354-357
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• 2002

Thermally grown gate oxide on 4H-SiC wafer was investigated. The oxide layers were grown at l150$^{\circ}C$ varying the carrier gas and post activation annealing conditions. Capacitance-Voltage(C-V) characteristic curves were obtained and compared using various gate electrode such as Al, Ni and poly-Si. The interface trap density can be reduced by using post oxidation annealing process in Ar atmosphere. All of the samples which were not performed a post oxidation annealing process show negative oxide effective charge. The negative oxide effective charges may come from oxygen radical. After the post oxidation annealing, the oxygen radicals fixed and the effective oxide charge become positive. The effective oxide charge is negative even in the annealed sample when we use poly silicon gate. Poly silicon layer was dope by POCl$_3$ process. The oxide layer may be affected by P ions in poly silicon layer due to the high temperature of the POCl$_3$ doping process.

• Journal of the Korean Ceramic Society
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• v.40 no.6
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• pp.589-593
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• 2003

Silica based Planar Lightwave Circuits (PLC) have been applied to various kinds of wave-guided optical passive devices. SiO$_2$ (buffer) and GeO$_2$-SiO$_2$ (core) thick films have been deposited by Flame Hydrolysis Deposition (FHD). The SiO$_2$ films were produced by the flame hydrolysis reaction of halide materials such as SiCl$_4$, POCl$_3$ and BCl$_3$ into an oxy-hydrogen torch. The P concentration increased from 2.0 to 2.8 at％ on increasing the POCl$_3$/BCl$_3$ flow ratio. The refractive index increased from 1.4584 to 1.4605 on increasing the POC1$_3$/BC1$_3$ flow ratio from 0.6 to 2.6. The refractive index of GeO$_2$-SiO$_2$ films was controlled by the GeCl$_4$ flow rate. The refractive index increased from 1.4615 to 1.4809 on increasing the GeCl$_4$ flow rate from 30 to 120 sccm.

• Journal of the Korean Chemical Society
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• v.54 no.4
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• pp.429-436
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• 2010

A series of some biologically active halogenopurines were synthesized from commercially available guanine (1). The reaction of guanine with acetic anhydride yielded 2,9-diacetylguanine (2-1) by acetylation reaction. Further treatment of 2-1 with $POCl_3$ by PEG-2000 phase transfer catalysis furnished the important compound 3a, then 2-amino-6-halogenopurines (3b-d) were obtained through chlorine-exchange halogenations between KX and 3a by TPPB phase transfer catalyst. Further, 2-halogenopurines (2-2a-d, 4-2a-d, 5a-d) were efficiently prepared from 2-amino-6-substituted purines (1, 3a, 4-1) via a diazotization catalyzed by their corresponding CuX, and some new compounds 2-2a, 2-2c, 2-2d, 4-2c, 4-2d, 5b, 5c and 5d have been discovered. The structures of synthesized compounds were mainly established on the basis of their elemental analysis, $^1H$ NMR, as well as their mass spectral data. All the title compounds were screened for their antifungal activities, and some of the compounds showed promising activity.

• Food Engineering Progress
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• v.15 no.4
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• pp.332-337
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• 2011

Physicochemical properties of hydroxypropylated and cross-linked (HPCL) rice starch were investigated. Dual modification of rice starch was carried out by hydroxypropylation using propylene oxide (2, 6, and 12%) and then crosslinking using phosphorus oxychloride (0.005% and 0.02%). Swelling power of dual-modified rice starch increased at lower temperature (60$^{\circ}C$) than that of native rice starch (70$^{\circ}C$). HPCL rice starch showed slightly lower solubility (1.6-6.1%) than native rice starch (2.2-13.8%). Solubility and swelling power tended to gradually increase with increasing phosphorus oxychloride contents. RVA pasting temperature (66.2-70.8$^{\circ}C$) and peak viscosity (160.6- 171.1 RVU) of HPCL rice starch were lower than that of those of native starch (71.3$^{\circ}C$, 190.4 RVU) and decreased with increasing propylene oxide concentration. DSC thermal transitions of HPCL rice starches shifted to lower temperature and show less amylopectin melting enthalpy (11.8-9.8 J/g) than that of native rice starch (11.9 J/g). Overall, physicohemical properties of HPCL rice starches were highly dependent on hydroxypropylation rather than crosslinking.

• Korean Journal of Food Science and Technology
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• v.39 no.5
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• pp.534-540
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• 2007

In this study, waxy rice starch was chemically modified using phosphorous oxychloride ($POCl_3$, 0.002-0.008%). Then the physicochemical properties of resulting cross-linked waxy rice starches were investigated in order to reduce the steeping time of Yukwa (a Korean oil-puffed rice snack) processing. The swelling powers of the cross-linked waxy rice starch samples were higher than the native waxy rice starch at temperatures above $60^{\circ}C$, and their increases were proportional to the $POCl_3$, concentration. The solubility of the cross-linked waxy rice starch was lower (1.6-3.4%) than the native waxy rice starch (2.7-6.1%). However, the moisture sorption isotherm of the cross-linked waxy rice starch was not significantly different from the native waxy rice starch. The rapid visco analyze. (RVA) pasting temperatures $(65.4-67^{\circ}C)$ of the cross-linked waxy rice starch were lower than those of the native starch $(67^{\circ}C)$. The RVA peak viscosities (287-337 RVU) of the cross-linked waxy rice starch were higher than that of native starch (179 rapid visco units (RVU)), and increased with increasing $POCl_3$ concentration. For the differential scornning calorimeter thermal characteristics, although Tc shifted toward higher temperatures with cross-linking, the To, Tp, and amylopectiin melting enthalpy of the cross-linked waxy rice starch showed no differences compared to the native waxy rice starch. The X-ray diffraction patterns of both the native and cross-linked waxy rice starches showed typical A-type crystal patterns, suggesting that cross-linking mainly occurs in the amorphous regions of starch granules. Therefore, the cross-linking reaction did not change the crystalline region, but altered the amorphous region of the waxy rice starch molecules, resulting in changes of solubility and RVA pasting properties in the cross-linked waxy rice starch. In summary, since cross-linked waxy rice starch has a high puffing efficiency and no browning reaction, it may be applicable for Yukwa processing without a long steeping process.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.11
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• pp.1342-1349
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• 1988

The dependence of the etch rates of differently doped poly-Si films on the gas composition, the chamber pressure and the RF power was investigated in detail. The highest anisotropy and the lowest CD loss were achieved at the $SF_6$-rich compositions, i.e., $Cl_2:SF_6$=17:33 (SCCM), in the $POCl_3$-doped poly-Si. The etch rates increased for n-type dopant (phosphorus), while decreased for p-type (boron) with increasing the doping levels irrespective of plasma parameters. And from the results of the activation of doped poly-Si films the active carrier concentrations as well as the doping concentrations were found to be responsible for the increase of the etch rate of the phosphorus-doped poly-Si.

• Journal of the Korean Institute of Telematics and Electronics
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• v.7 no.2
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• pp.33-42
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• 1970

This report is concerned with the fahrication with the falricationof silicon VVC diode by the double diffusion planer technique. At first, some design charts for VVC diode were derived by considering the voltage-capacitance relations, the critical field intensity at the metallurgical junction, and the cut-off frequency of the diode. These charts enables the fabrication engineers to design VVC diode easily without going into the sophisticated design theory. We started with a 2.5 ohm-cm n-type epitaxial silicon wafer. The phosphorous was diffused by POCl3 impurity source. Then boron diffusion followed make hyperabrupt p-n junction by BN source. The maximum to minimum capacitance ratio of the diode as a tuning diode for a TV tuner made in these experiments was 4:1. Measured electrical characteristics of the sample diodes showed in good agreement with the theoretical expectations. Slicing and polishing technique of the silicon wafer and diffusion technique of the impurity atoms, which were employed in our study, are also stated briefly in this report.

• Bulletin of the Korean Chemical Society
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• v.24 no.4
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• pp.473-478
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• 2003

3-Amino-2-hydroxy-4(3H)-quinazolinone (3) was prepared via condensation of 1 with hydrazine hydrate. Treatment of 3 with appropriate acid in $POCl_3$, ethyl chloroacetate and activated olefinic compounds in DMF yielded the corresponding 3-(substituted)amino-2-hydroxy-4(3H)-quinazolinones 4, 5 and 6. The electron impact ionization mass spectra of compounds 3 and 4 show a weak molecular ion peak and a base peak of m/z 146 resulting from a cleavage fragmentation. The compounds 5 and 6 give a characteristic fragmentation pattern with a very stable fragment of benzopyrazolone (m/z 132).

• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2413-2418
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• 2009

Rates of solvolyses of 4-nitrophenyl phenyl thiophosphorochloridate (4-N$O_2$PhOP(S)(Cl)OPh, $\underline{1}$) in ethanol, methanol, and aqueous binary mixtures incorporating ethanol, methanol, acetone, and 2,2,2-trifluroethanol (TFE) are reported. Thermodynamic parameters were determined at several temperatures in three representative solvents. The extended Grunwald-Winstein equation was applied to 29 solvents and the correlation coefficient (R) showed 0.959. The sensitivities (l = 1.37 and m = 0.62) are similar to those obtained for diphenyl thiophosphorochloridate (($PhO)_2$PSCl, $\underline{2}$), diphenyl phosphorochloridate (($PhO)_2$POCl, $\underline{3}$), diphenyl phosphinic chloride ($Ph_2$POCl, $\underline{4}$), and diphenyl thiophosphinic chloride ($Ph_2$PSCl, $\underline{5}$). The solvolytic reaction mechanism of 4-nitrophenyl phenyl thiophosphorochloridate ($\underline{1}$) is suggested to be proceeded a $S_N$2 process as previously reported result. The activation enthalpies are shown as slightly low as ${\Delta}H^{\neq}\;=\;9.62\;to\;11.9\;kcal{\cdot}mol^{-1}$ and the activation entropies are shown as slightly high negative value as ${\Delta}S^{\neq}\;=\;-34.1\;to\;-44.9\;cal{\cdot}mol^{-1}{\cdot}K^{-1}$ compared to the expected $S_N$2 reaction mechanism. Kinetic solvent isotope effects are accord with a typical $S_N$2 mechanism as shown in the range of 2.41 in MeOH/ MeOD and 2.57 in $H_2O/D_2O$ solvent mixtures.

• Archives of Pharmacal Research
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• v.13 no.2
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• pp.198-200
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• 1990

3, 4-Diphenyl-5-cyanopyridazin-6-one 3 was prepared from the reaction of cyano acetamide 2 with benzihydrazone in dry pyridine. A series of its derivatives was prepard. Tolyl and benene sulphonyl derivatives 6a and 6b are also prepared. 3, 4-Diphenyl-5-cyanopyridazin-6-thione 5 was obtained from 3 by the action of $P_2S_5$ while 3, 4 diphenyl-5-cyano 6-chloropyridazine 4 was obtained from 3 by the action POCl$_3$. The reaction of 4 with hydrazine hydrate directly afforded the pyrazolopyridazine derivative 7. Compound 4 also reacted with phenylhydrazine, aniline, thiophenol and anthranilic acid to yield pyridazine derivatives 8, 9, 10 and 11, respectively. On treatment of compound 11 with acetic anhydride it cyclised to afford pyridazino pyrimidine derivatives 12.