• Title/Summary/Keyword: reoxidation

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Elimination of Hole Traps on Si Wafer using Reoxidation method (REOXIDATION법을 이용한 Si WAFER의 HOLE TRAP의 제거)

  • Hong, Soon-Kwan;Ju, Byeong-Kwon;Kim, Chul-Ju
    • Proceedings of the KIEE Conference
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    • 1987.07a
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    • pp.433-435
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    • 1987
  • Thermal reoxidation was carried out to eliminate hole traps at the surface of Si wafer. As the result, the good surface state of wafer was obtained and hole traps were eliminate at the inversion layer. For the evaluation of reoxidation effects. MOS diode was fabricated and its C-Y curve was plotted.

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Measurement of Interface Trapped Charge Densities $(D_{it})$ in 6H-SiC MOS Capacitors

  • Lee Jang Hee;Na Keeyeol;Kim Kwang-Ho;Lee Hyung Gyoo;Kim Yeong-Seuk
    • Proceedings of the IEEK Conference
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    • summer
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    • pp.343-347
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    • 2004
  • High oxidation temperature of SiC shows a tendency of carbide formation at the interface which results in poor MOSFET transfer characteristics. Thus we developed oxidation processes in order to get low interface charge densities. N-type 6H-SiC MOS capacitors were fabricated by different oxidation processes: dry, wet, and dry­reoxidation. Gate oxidation and Ar anneal temperature was $1150^{\circ}C.$ Ar annealing was performed after gate oxidation for 30 minutes. Dry-reoxidation condition was $950^{\circ}C,$ H2O ambient for 2 hours. Gate oxide thickness of dry, wet and dry-reoxidation samples were 38.0 nm, 38.7 nm, 38.5 nm, respectively. Mo was adopted for gate electrode. To investigate quality of these gate oxide films, high frequency C- V measurement, gate oxide leakage current, and interface trapped charge densities (Dit) were measured. The interface trapped charge densities (Dit) measured by conductance method was about $4\times10^{10}[cm^{-1}eV^{-1}]$ for dry and wet oxidation, the lowest ever reported, and $1\times10^{11}[cm^{-1}eV^{-1}]$ for dry-reoxidation

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Surface Reoxidation Mechanism and Electrical Properites of SBLC in $BaTiO_3$ System ($BaTiO_3$계 SBLC의 표면 재산화 형성 기구 및 전기적 성질)

  • 이형규;김호기
    • Journal of the Korean Ceramic Society
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    • v.23 no.5
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    • pp.55-60
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    • 1986
  • A mechanism for formation of surface reoxidation layer in Surface Boundary Layer Capacitor (SBLC) has been studied. SBLC were prepared by reduction of $BaTiO_3$ doped with $Bi_2O_3$ and electrode firing of silver paste containing $Bi_2O_3$ The apparent dielectric constant was in the order of $10^5$ and the insulation resistance larger than $10^6$$\Omega$ It can be expected that $Bi_2O_3$ dopant in $BaTiO_3$ plays the role of inhibition of grain growth and decreasing the resistivity of $BaTiO_3$. In order to confirm the process of surface reoxidation layer effects of atmosphere and annealing time in electrode sintering were investigated.

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Redox Behaviors of NiO/YSZ Anode Tube in Anode-Supported Flat Tubular Solid Oxide Fuel Cells (평관형 고체 산화물 연료전지의 연료극 지지체 NiO/YSZ의 환원 및 재산화 거동 특성)

  • Song, Rak-Hyun;Lee, Gil-Yong;Shin, Dong-Ryul
    • Journal of Hydrogen and New Energy
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    • v.17 no.1
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    • pp.82-89
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    • 2006
  • The redox behaviors of anode-supported flat tube for solid oxide fuel cell has been studied. The mass change of the extruded NiO/YSZ anode flat tube during redox cycling was examined by thermogravimetric analysis(TGA). The result of TGA was shown a rapidly mass change in the range of $455\;-\;670^{\circ}C$ and the reoxidation of the NiO/YSZ anode was almost completed at $750^{\circ}C$. The starting temperature of reoxidation and the maximum temperature of oxidation rate decreased with increasing the reoxidation cycle, which is attributed to the increased porosity caused by volume change. Bending strengths of the NiO/YSZ anode after redox cycling were 96 - 80 MPa and the bending strength decreased slightly with increasing the redox cycle. On the other hand, the bending strength of the NiO/YSZ anode with electrolyte showed 130 MPa after first redox cycling but decreased rapidly with increasing the redox cycle. From the results of the bending test and the microstructure observation, we conclude that the crack initiation of the electrolyte-coated NiO/YSZ anode was induced easily at interface of electrolyte/anode tube and propagated cross the electrolyte.

High-k Gate Dielectric for sub-0.1$\mu\textrm{m}$ MOSFET (차세대 sub-0.1$\mu\textrm{m}$급 MOSFET소자용 고유전율 게이트 박막)

  • 황현상
    • Proceedings of the IEEK Conference
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    • 2000.06b
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    • pp.20-23
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    • 2000
  • We have investigated a process for the preparation of high-quality tantalum oxynitride ( $T_{a}$ $O_{x}$ $N_{y}$) via the N $H_3$ annealing of 7$_{a2}$ $O_{5}$, for use in gate dielectric applications. Compared with tantalum oxide (7$_{a2}$ $O_{5}$), a significant improvement in the dielectric constant was obtained by the N $H_3$ treatment. In addition, light reoxidation in a wet ambient at 45$0^{\circ}C$ resulted in a significantly reduced leakage current. We confirmed nitrogen incorporation in the tantalum oxynitride ( $T_{a}$ $O_{x}$ $N_{y}$ by Auger Electron Spectroscopy. By optimizing the nitridation and reoxidation process, we obtained an equivalent oxide thickness as thin as 1.6nm and a leakage current of less than 10mA/$\textrm{cm}^2$ at 1.5V..5V..5V..5V..5V..5V.

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Characteristics Variation of Oxide Interface Trap Density by Themal Nitridation and Reoxidation (산화막의 질화, 재산화에 의한 계면트랩밀도 특성 변화)

  • 백도현;이용재
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 1999.05a
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    • pp.411-414
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    • 1999
  • 70 ${\AA}$-thick oxides nitridied at various conditions were reoxidized at pemperatures of 900$^{\circ}C$ in dry-O$_2$ ambients for 5~40 mininutes. The gate oxide interface porperties as well as the oxide substrate interface properties of MOS(Metal Oxide Semiconductor) capacitors with various nitridation conditions, reoxidation conditions and pure oxidation condition were investigated. We stuided I$\sub$g/-V$\sub$g/ characteristics, $\Delta$V$\sub$g/ shift under constant current stress from electrical characteristics point of view and breakdown voltage from leakage current point of view of MOS capacitors with SiO$_2$, NO, RNO dielectrics. Overall, our experimental results show that reoxidized nitrided oxides show inproved charge trapping porperites, I$\sub$g/-V$\sub$g/ characteristics and gate $\Delta$V$\sub$g/ shift. It has also been shown that reoxidized nitridied oxide's leakage currented voltage is better than pure oxide's or nitrided oxide's from leakage current(1${\mu}$A) point of view.

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Improvement of Thin-Gate Oxide using Nitridation and Reoxidation (질화와 재산화를 이용한 얇은 게이트 산화막의 질적 향상)

  • 이정석;장창덕;이용재
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1998.11a
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    • pp.1-4
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    • 1998
  • In this paper, we have studied a variation of I-V characteristics, and time-dependent dielectric breakdown(TDDB) of thin layer NO and ONO film depending on nitridation and reoxidation time, respectively, and measured a variation of leakage current and charge-to-breakdown(Q$\_$bd/) of optimized NO and ONO film depending on ambient temperature, and then compared with the properties of conventional SiO$_2$. From the results, we find that these NO and ONO thin films are strongly influenced by process time and the optimized ONO film shows superior dielectric characteristics, and Q$\_$bd/ performance over the NO film and SiO$_2$, while maintaining a similar electric field dependence compared with NO layer.

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Effects of Wet Oxidation on the Nitride with and without Annealing (열처리 전후의 질화막에 대한 습식산화의 효과)

  • Yun, Byeong-Mu;Choe, Deok-Gyun
    • Korean Journal of Materials Research
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    • v.3 no.4
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    • pp.352-360
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    • 1993
  • A nitride layer was df'posited on the thermal oxide layer by LPCVD process. ONO(oxidenitricle oxide) capacitors with various thickness of component layer wore fabricated by wet reoxidation of the nitride with and without anrwalmg treatment and their properties were investigated. As a result of observation on the refrative index and etching behavior of the ONO fIlms, the nitride layer OF 40 A thick ness was not so dense that the bottom oxide during the reoxidation process and the capability of securing the capacitance decreased. The conduction current in the ONO multl-Iayer dielctric film was reduced as the bottom(or top) oxide layer became thicker. However, in the case of oxide with thickness more than 50A, it merely plays a factor of reduction in capacitance, and the effect of barrier for hole injection was not so much increased. Annealing of the nitride laypr bpfore reoxidation did not show a grpat effects on the refractive index and capacitance of the film, however, the annealing process increased the breakdown voltage by 2${\cdot}$V.

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Properties of the oxynitride films prepared by reoxidation of thermal oxide in $N_2O$ ($N_2O$ 가스에서 열산화막의 재산화에 의해 형성된 oxynitride막의 특성)

  • Bae, Sung-Sig;Lee, Cheol-In;Choi, Hyun-Sik;Seo, Yong-Jin;Kim, Tae-Hyung;Kim, Chang-Il;Chang, Eui-Goo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1993.05a
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    • pp.39-43
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    • 1993
  • Electricial characteristics of gate dielectrics prepared by reoxidation of thermal $SiO_2$ in nitrous oxide gas have been investigated. 10 and 19nm-thick oxides were reoxidized at temperatures of $900-1000^{\circ}C$ for 10-60 min in $N_2O$ ambient. As reoxidation proceeds, it is shown that nitrogen concentration at $Si/SiO_2$ interface increases gradually through the AES analysis. Nitrogen pile-up at $Si/SiO_2$ interface acts as a oxidant diffusion barrier that reduces the oxidation rate significantly. And it not only strengthen oxynitride structure at the interface but improve the gate dielectric qualities. Reliabilities of oxynitride films are conformed by the breakdown distributions and constant current stress technique. Therefore, the oxynitride films made by this process show a good promise for future ULSI applications.

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Characteristics of reoxidation of nitried oxide for gate dielectric of charge trapping NVSM (전하트랩형 NVSM의 게이트 유전막을 위한 질화산화막의 재산화특성에 관한 연구)

  • 이상은;한태현;서광열
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.11 no.5
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    • pp.224-230
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    • 2001
  • The characteristics of $NO/N_2O$ annealed reoxidized nitrided oxide being studied as super thin gate oxide and gate dielectric layers of Non-Volatile Semiconductor Memory (NVSM) were investigated by Dynamic Secondary Ion Mass Spectrometry (D-SIMS), Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS), and Auger Electron Spectroscopy (AES). The specimen was annealed by $NO/N_2O$ after initial oxide process and then rcoxidized for nitrogen redistribution in nitrided oxide. Out-diffusion of incorporated nitrogen during the wet oxidation in reoxidation process took place more strongly than that of the dry oxidation. It seems to indicate that hydrogen plays a role in breaking the Si N bonds. As reoxidation proceeds, incorporated nitrogen of $NO/N_2O$ annealed nitrided oxide is obsen-ed to diffuse toward the surface and substrate at the same time. ToF-SIMS results show that SiON species are detected at the initialoxide interface, and Si,NO species near the new $Si_2NO$ interface that formed after reoxidation. These SiON and $Si_2NO$ species most likely to relate to the origin of the state of memory charge traps in reoxidized nitrided oxide, because nitrogen dangling bonds of SiON and silicon dangling bonds of $Si_2NO$ are contained defects associated with memory effect.

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