ICMCTF 2012! - CD-Lab Application Oriented Coating Development

innovative and low-cost metallization method. Despite this advantage of the
direct printing, there is still limited usage in microwave and millimeterwave
applications. In order to expand the application fields of the printed
electronic devices, the sufficient information for the high frequency
performance of the directly printed circuits should be investigated. Also,
high reliability of the printed electronic devices must be guaranteed for
commercialization of feasible radio frequency (RF) applications. The
properties of the printed thin film are determined by heat treatment and user
environment. Therefore, RF properties of screen-printed silver (Ag) films
were characterized with an environmental reliability test. A Ag nanopaste
was screen-printed onto a silicon (Si) substrate passivated with SiO2. The
printed films were sintered at 250 ˚C for 30 min, and then were placed in a
chamber with 85˚C/85%RH for various durations (100, 300, 500, 1000 hrs).
The microstructural evolution and thickness profiles of the sintered
conductive tracks were investigated with a field emission scanning electron
microscope and 3D nano-scan view, respectively. Oxide layers on the Ag
thin films were analyzed with the Auger electron spectroscopy. A network
analyzer and Cascade’s probe system in the frequency range of 10 MHz to
20 GHz were employed to measure the S-parameters of the Ag thin films.
From the experimental results, the insertion losses at high frequencies
increased with increasing the exposure durations to the 85 ºC/85% RH due
to the thicker oxide layers. The RF properties of the printed Ag films were
affected by the microstructural evolution and the oxide layers, which will be
deeply discussed in the conference site and full manuscript.
4:10pm TS2-2-10 The Bipolar Resistance Switching Behavior with a
Pt/CoSiOX/TiN Structure of Nonvolatile Memory Device, Y.E. Syu
(syuyongen@gmail.com), National Sun Yat-Sen University, Taiwan, G.W.
Chang, National Chiao Tung University, Taiwan
This paper investigates characteristics and physical mechanism of the
resistance random access memory (RRAM) device with TiN/CoSiOX/Pt
structure. The device exhibits excellent characteristic with good endurance
of more than 10 5 times, long retention time of 10 4 s in 125 � and more
stable in resistance switching state. In general, the mechanism is regarded as
a redox reaction in the dielectric interface between the TiN electrode and
the conductive filament. In this study, both high resistance state (HRS) and
low resistance state (LRS) seem to be independent of cell size, so that the
formation/rupture of localized conduction filament is preferred as the
driving mechanism of the resistance switching in the Pt/CoSiOX/TiN
system. Furthermore, the switching mechanism is investigated by currentvoltage
(IV) curve fitting to confirmation the filament. Also, the
asymmetric phenomenon of the carrier conductor behavior is found at the
HRS in high electric filed. The switching behavior in the TiN/WSiOX/Pt
device is regard as tip electric filed by localizing filament between the
interface of top electrode and insulator. In addition, the resistance state is
relating with the thickness of switching layer between the TiN electrode and
the conductive filament.
4:30pm TS2-2-11 A low-temperature method to improve the
performance of Ni: SiO2 -based nonvolatile memory by supercritical
CO2 fluid, S.L. Chuang (gizvvs@hotmail.com), National Sun Yat-Sen
University, Taiwan
In this study, the highly reliable and uniform bipolar resistance switching
behavior was achieved in Pt/ Ni: SiO2 /TiN resistive random access memory
(RRAM) device. This device has above 3 orders (ROFF/RON) of magnitude
memory window, good 10 6 -cycle endurance, and the excellent retention
reliability during 10000 sec at 85 o C. Based on the analytic results, the lowtemperature
supercritical CO2 (SCCO2) fluid technology was employed to
treat the Ni: SiO2 resistance-switching layer of device at 150 o C. After
SCCO2 fluid treatment, the current at the high-resistance state (HRS) of
device was reduced significantly. Furthermore, the carrier conduction
mechanism at HRS transformed from Frenkel-Poole emission to Schottky
emission in the high-voltage region. SCCO2 fluid can deliver the oxidants
into Ni: SiO2 thin film. Based on the XPS and the FTIR material analyses
results, a model is presented which describes the traps within Ni: SiO2 thin
film was passivated by SCCO2 fluid.
4:50pm TS2-2-12 Resistive switching characteristics induced by
doping of Sn in SiO2-based nonvolatile memory, T.M. Tsai, K.C. Chang,
T.C. Chang (tcchang@mail.phys.nsysu.edu.tw), Y.E. Syu, D.S. Gan,
National Sun Yat-Sen University, Taiwan
In this study, we applied doping Sn into the SiO2 insulator to induce the
resistive switching characteristics by the technique of SiO2 and Sn cosputtering
at room temperature. The fitting results of current-voltage curve
indicated that the carrier conduction mechanism at a high resistive state is
complied with the Poole-Frenkel emission while the carrier transfer
mechanism at a low resistive state is dominated by the Ohmic’s conduction.
This phenomenon is consistent with the filament theory. The effect of Sn
doping in SiO2 are discussed by fourier transform infrared spectroscopy
and X-ray photoelectron spectroscopy. Additionally, good retention and
Monday Afternoon, April 23, 2012 22
endurance characteristics are exhibited in the Sn-doped SiO2 resistance
switching memory.