Sukirno

Publications (10)3.89 Total impact

• Article: Comparison of electron transmittances and tunneling currents in an anisotropic TiNx/HfO2/SiO2/p-Si(100) metal—oxide—semiconductor (MOS) capacitor calculated using exponential- and Airy-wavefunction approaches and a transfer matrix method

  Fatimah A. Noor, Mikrajuddin Abdullah, Sukirno, Khairurrijal
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  ABSTRACT: Analytical expressions of electron transmittance and tunneling current in an anisotropic TiNx/HfO2/SiO2/p-Si(100) metal—oxide—semiconductor (MOS) capacitor were derived by considering the coupling of transverse and longitudinal energies of an electron. Exponential and Airy wavefunctions were utilized to obtain the electron transmittance and the electron tunneling current. A transfer matrix method, as a numerical approach, was used as a benchmark to assess the analytical approaches. It was found that there is a similarity in the transmittances calculated among exponential- and Airy-wavefunction approaches and the TMM at low electron energies. However, for high energies, only the transmittance calculated by using the Airy-wavefunction approach is the same as that evaluated by the TMM. It was also found that only the tunneling currents calculated by using the Airy-wavefunction approach are the same as those obtained under the TMM for all range of oxide voltages. Therefore, a better analytical description for the tunneling phenomenon in the MOS capacitor is given by the Airy-wavefunction approach. Moreover, the tunneling current density decreases as the titanium concentration of the TiNx metal gate increases because the electron effective mass of TiNx decreases with increasing nitrogen concentration. In addition, the mass anisotropy cannot be neglected because the tunneling currents obtained under the isotropic and anisotropic masses are very different.
  Journal of Semiconductors 12/2010; 31(12):124002.
• Article: Electron and hole components of tunneling currents through an interfacial oxide-high-k gate stack in metal-oxide-semiconductor capacitors

  Fatimah A. Noor, Mikrajuddin Abdullah, Sukirno,, Khairurrijal,, Akio Ohta, Seiichi Miyazaki
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  ABSTRACT: Two different components of tunneling current in the TiN/HfSiOxN/SiO2/p-Si(100) metal-oxide-semiconductor capacitor have been presented. The tunneling currents were calculated by taking into account a longitudinal-transverse kinetic energy coupling. The calculated tunneling currents were compared with that measured ones by employing the electron and hole effective masses and phase velocities as fitting parameters. It has been shown that hole tunneling currents dominate at low voltages whereas at high voltages the tunneling currents are mainly contributed by electrons. It has also been found that the effective mass of hole in the HfSiOxN layer is higher than that of electron. The gate electron and substrate hole velocities are 1×105 m/s independent of the HfSiOxN thickness. In addition, it is speculated that the electron and hole effective masses in the HfSiOxN layer perhaps increase as its thickness decreases.
  Journal of Applied Physics 11/2010; 108(9):093711-093711-5. · 2.17 Impact Factor
• Article: Kajian Kapasitansi Diferensial Lapisan Ganda Elektrik (Electric Double Layer = EDL) pada Cairan Ionik (Ionic Liquid) sebagai Dielektrik Gate pada Field Effect Transistor

  Aliah Hasniah, Sustini Euis, Sukirno
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  ABSTRACT: Dewasa ini, pemanfaatan cairan ionik (ionic liquid = IL) sebagai dielektrik gate pada transistor efek medan (field effect transistor = FET) mendapat perhatian yang sangat besar karena mampu menghasilkan kapasitansi yang besar sehingga pembawa muatan dalam jumlah yang banyak dapat diakumulasikan dengan potensial gate yang rendah. Untuk maksud tersebut, dilakukan uji kapasitansi terhadap frekuensi dengan menggunakan teknik impedansi pada kapasitor EDL Pt/IL/Pt. untuk enam jenis IL. Diperoleh bahwa kapasitansi pada EDL IL berbanding terbalik dengan panjang rantai alkil kation imidazolium dan IL dengan anion BF4 mempunyai kapasitansi yang lebih besar dibandingkan dengan IL menggunakan anion TFSI. Dengan demikian AMIm-BF4 merupakan IL yang baik untuk diterapkan sebagai dielektrik gate pada EDLFET.
  Jurnal Nanosains & Nanoteknologi. 01/2009;
• Source

  Available from: itb.ac.id

  Article: Penentuan Ketebalan Lapisan Al untuk Katalis pada Deposisi SiNW Menggunakan Transmitansi Optik

  Setiawan Andhy, Latununuwe Altje, M Ramdlan Kirom, Winata Toto, Sukirno
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  ABSTRACT: Pada deposisi SiNW diameter butiran katalis yang terbentuk pada tahap nukleasi berpengaruh pada pembentukan SiNW. Pembentukan butiran biasanya dilakukan dengan cara menumbuhkan lapisan tipis diikuti dengan proses annealing. Pada proses ini butiran yang terbentuk dipengaruhi oleh ketebalan lapisan tipis. Telah dilakukan penumbuhan lapisan tipis Al menggunakan metoda evaporasi termal. Pengukuran ketebalan dieksplorasi menggunakan karakterisasi SEM, AFM dan spektrometer UV-Vis. Berdasarkan hasil pencitraan dan data transmitansi optik melalui spektrometer UV-Vis diperoleh nilai koefisien attenuasi untuk setiap panjang gelombang yang digunakan. Penggunaan metoda transmitansi optik ini dapat digunakan sebagai alternatif dalam menentukan ketebalan lapisan Al yang berorde nanometer dalam rangkaian sintesis katalis untuk penelitian deposisi SiNW. Berdasarkan hasil eksperimen ini diperoleh cara sederana dalam menentukan ketebalan lapisan menggunakan spektrometer UV-Vis (pada panjang gelombang 300 nm sampai 820 nm).
  Jurnal Nanosains & Nanoteknologi. 01/2009;
• Source

  Available from: itb.ac.id

  Article: Kajian Pembuatan Nanotube Karbon dengan Menggunakan Metode Spray Pyrolysis

  Fatimah A Noor, Lizi L Zaenufar, Yulkifli, Abdullah Mikrajuddin, Sukirno, Khairurrijal
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  ABSTRACT: Dalam penelitian ini, nanotube karbon dibuat dengan menggunakan metode spray pyrolysis tanpa menggunakan gas pembawa pada temperatur 850°C. Metode ini merupakan metode yang sering digunakan dalam sintesis nanotube karbon karena dapat menghasilkan nanotube karbon dengan kualitas yang baik dengan biaya produksi yang murah. Dalam spray pyrolysis, benzene sebagai sumber karbon terdekomposisi secara termal dengan bantuan ferrocene yang berperan sebagai katalis dalam menghasilkan nanotube karbon. Penelitian dilakukan dengan memvariasikan massa ferrocene dan waktu pemanasan. Dari hasil karakterisasi SEM dan EDX diketahui bahwa perubahan struktur dan diameter nanotube karbon dipengaruhi oleh massa ferrocene yang dilarutkan dalam benzene. Juga diketahui bahwa penambahan waktu pemanasan tidak berpengaruh pada perbaikan struktur nanotube karbon.
  Jurnal Nanosains & Nanoteknologi. 01/2009;
• Article: Model of a tunneling current in an anisotropic Si/Si1−xGex/Si heterostructure with a nanometer-thick barrier including the effect of parallel–perpendicular kinetic energy coupling

  Lilik Hasanah, Mikrajuddin Abdullah, Sukirno, Toto Winata, Khairurrijal
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  ABSTRACT: A theoretical model of an electron tunneling current in an anisotropic Si/Si1−xGex/Si heterostructure was developed. The parallel and perpendicular kinetic energies were coupled and the coupling was included in expressing the electron transmittance through the anisotropic heterostructure. The model was applied to the anisotropic Si(1 1 0)/Si0.5Ge0.5/Si(1 1 0) heterostructure with a 25 nm thick strained Si0.5Ge0.5 potential barrier, in which each layer of the heterostructure has three valleys (valleys 1, 2 and 3) with different inverse effective mass tensors and a conduction band discontinuity of 216 meV. The Si(1 1 0)/SiGe structure implies that only the four equivalent valleys (valleys 1 and 2) are considered in calculations. It was found that the transmittance for valley 1 is the same as that for valley 2 due to the same barrier height. The transmittance decreases as the electron phase velocity increases because the electron phase velocity enhances the barrier height. Moreover, the total tunneling current density for the phase velocity higher than 3 × 105 m s−1 differs significantly from that obtained without including the kinetic energy coupling. As the electron phase velocity gets higher, the total tunneling current density lowers. This implies that the coupling effect cannot be ignored for electrons with high phase velocity.
  Semiconductor Science and Technology 11/2008; 23(12):125024. · 1.72 Impact Factor
• Conference Proceeding: Modeling of stress-induced leakage current in thin gate oxides

  Khairurrijal, F.A. Noor, Sukirno
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  ABSTRACT: An analytic model of the stress-induced leakage current in thin gate oxides was developed under the assumptions that traps created in the gate oxide during high field injection of electrons have an exponential distribution in energy and transport of the electrons localized in the traps is due to an activated process of motion from one trap to another. The electric field and temperature dependence of the leakage current in a wide range were explained successfully by the model.
  Semiconductor Electronics, 2002. Proceedings. ICSE 2002. IEEE International Conference on; 01/2003
• Conference Proceeding: Low Temperature Carbon Nanotube Fabrication using Very High Frequency-Plasma Enhanced Chemical Vapour Deposition Method

  Sukirno, S.Z. Bisri, L. Hasanah, Mursal, I. Usman, A.B. Suryamas
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  ABSTRACT: It is explained one of the carbon nanotube research progress in Indonesia. It is being attempted a carbon nanotube growth using the modifications of existing home made PECVD system, which are Very-High Frequency PECVD (VHF-PECVD) and Hotwire VHF-PECVD (HW-VHF-PECVD). They are catalytic growth processes, which various metal catalyst thin films were growth on the Silicon substrate, such as Fe catalyst grown by using dc-Unbalanced Magnetron Sputtering Method and Al as well as Ni catalyst grown by high vacuum thermal evaporation method. SiO₂ buffer layer was also grown beneath the Al catalyst layer. Some post-treatments for the catalyst thin films were also conducted, which were post- annealing process under various atmosphere conditions, N₂, NH₃ and free air. By using a single gas source, which was methane as the source of carbon, a carbon nanotube fabrication has been attempted at relatively low temperature, 400degC. It was expected that the high value of plasma frequency could lead to higher dissociation rate of methane to produce much carbon radicals. Meanwhile, the usage of hot-wire filament was expected to pre-decompose some the methane gas before reach the reactor in order to produce some of hydrogen radicals, which might be needed for CNT growth process. From morphological characterization results, it has been achieved some carbon sub-microstructure, in 100 nm of grain size and vertically aligned. From the composition characterization results, it has been confirmed that carbon atoms fraction were quite significant and the catalytic growth mechanism was happened. Furthermore, from the SEM characterization results of the samples, which was grown on the buffered catalyst, showed that a long aligned horizontal carbon nanotube has been grown.
  Semiconductor Electronics, 2006. ICSE '06. IEEE International Conference on;
• Conference Proceeding: Comparison of Electronic Transport Parameter of CNT(10,10)/CNT(17,0) and CNT(5,5)/CNT(8,0) Carbon Nanotube Metal-Semiconductor On-Tube Heterojunction

  Sukirno, S.Z. Bisri, Irmelia, L. Hasanah, A.B. Suryamas, I. Usman, Mursal
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  ABSTRACT: Carbon nanotubes research is one of the top five hot research topics in physics. It is because of its unique properties and functionalities, which leads to wide-range applications. One of the most interesting potential applications is in term of nanoelectronic device. There is a possibility to found some unique structure, where different carbon nanotubes are connected coaxially. It has been modeled carbon nanotubes heterojunction, which was built from two different carbon nanotubes, that one is metallic and the other one is semiconducting. There are two different carbon nanotubes metal-semiconductor heterojunction. The first one is built from CNT (10,10) as metallic carbon nanotube and CNT (17,0) as semiconductor carbon nanotube. The other one is built from CNT (5,5) as metallic carbon nanotube and CNT (8,0). All of the semiconducting carbon nanotubes are assumed to be a pyridine-like N-doped. Those two heterojunctions are different in term of their structural shape and diameter. It has been calculated their charge distribution and potential profile, which would be useful for the simulation of their electronic transport properties. The calculations are performed by using self-consistent method to solve non-homogeneous Poisson's equation with aid of universal density of states calculation method for carbon nanotubes. The calculations are done by varying the doping fraction of the semiconductor carbon nanotubes. It is obtained that the charge are distributed almost evenly along the semiconducting carbon nanotubes and the potential profile peaks in the vincinity of semiconducting carbon nanotubes center position, with some valley-shapes that show some sign of charge confinements nearby. However, from the comparison of two different heterojunctions, it could be inferred that the geometrical aspects of the heterojunction building blocks has effect on their electronic transport parameter. It is also obtained the calculation results of the electron tunneling transmission - coefficient that transported through the heterojunction, which has energy lower than the potential barrier value.
  Semiconductor Electronics, 2006. ICSE '06. IEEE International Conference on;
• Article: Radiation formation of PVA/PVP hydrogel and its efficacy test for wound dressing application

  Z. Zainuddin, D. J. T. Hill, A. K. Whittaker, M.T. Razzak, D.S. Pangerteni, Sukirno