Browsing by Author "Hsu, Y. Y."

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Highly Scalable Hafnium Oxide Memory with Improvements of Resistive Distribution and Read Disturb Immunity
(2009)
Chen, Y. S.
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Lee, H. Y.
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Chen, P. S.
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Gu, P. Y.
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Chen, C. W.
A 30x30 nm(2) HfOx resistance random access memory (RRAM) with excellent electrical performances is demonstrated for the scaling feasibility in this work. A 1 Kb one transistor and one resistor (1T1R) array with robust characteristics was also fabricated successfully. The device yield of the 1 Kb array is 100%, and the endurance for these devices can exceed 10(6) cycles by a pulse width of 40 ns. Two effective verification methods, which make a tight distribution of high resistance (R-HIGH) and low resistance (R-LOW) are proposed for the array to ensure a good operation window. A thin A1O(x) buffer layer under the HfOx layer was adopted to enhance the read disturb immunity. Without large parasitic capacitance, the 1T1R RRAM devices exhibit excellent program(PGM)/erase(ERS) disturb immunity.
Improved Field Emission Characteristics with different Electrode Materials by forming process in a Quasi-planar Thin Film Field Emission Diode
(2010-01-01)
Chang, C. T.
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Hsu, Y. Y.
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Lin, K. C.
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Tsai, Wan-Lin
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Chien, Yun-Shan
The essay was reported the different electrode materials in a quasi-planar thin film field emission diode by different forming process. The forming process causes an increased surface roughness of emitters or reduced the work function of the emitter and results in a higher field enhancement factor, which shows better field emission characteristics. The turn on voltage could from 15 V to 8 V and 6.5V with Co and Pd electrode at the emission current of 100 nA for samples.
Novel ultra-low voltage and high-speed programming/erasing schemes for SONOS flash memory with excellent data retention
(2007)
Chung, Steve S.
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Tseng, Y. H.
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Lai, C. S.
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Hsu, Y. Y.
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Ho, Eric
A novel cell operation scheme featuring low voltage, high speed, and excellent data retention has been proposed for SONOS flash memory First, in 1bit/cell operation, program is achieved by a back-bias assisted hot hole injection, while erase is achieved by forward-bias assisted electron injection. For a thick tunnel oxide (50A degrees), the ultra-low voltage (similar to 5V) and ultra-fast speed (<1 mu sec) operation has been the record reported to date. On the other hand, a 2 bit/cell operation is also demonstrated, in which very good retention can be achieved in comparison to conventional operation schemes, e.g., CHE (channel hot electron) or BTB(Band-to-band) tunneling etc.
Structural distortion and electronic states of Rb doped WO3 by X-ray absorption spectroscopy
(2016-01-01)
Wang, Y. C.
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Hsu, C. H.
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Hsu, Y. Y.
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Chang, C. C.
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Dong, C. L.
Rubidium tungsten bronzes (RbxWO3) have recently attracted much attention due to their intriguing phenomena, such as complex structural phase transitions, strong electron-phonon coupling, and superconducting properties. This study investigates the local atomic and electronic structures of RbxWO3 (0.17 <= x <= 0.33). X-ray powder diffraction patterns showed a hexagonal tungsten bronze (HTB) phase. X-ray absorption spectra (XAS) at the W L-3-edge and Rb K-edge of RbxWO3 were carried out. The XAS analysis indicated a local distorted WO6 octahedron which leads to a splitting of e(g) and t(2g) energy states in the tungsten 5d orbital and this splitting of energy levels exhibited an asymmetrical behavior at x = 0.23 and 0.27. Overall analysis revealed a distortion of local atomic structure of the WO6 octahedra by rubidium doping, leading to the modification of the electronic structures of e(g) and t(2g) states in the tungsten 5d orbital, thereby accounting for the property changes in CDW formation and superconducting transition temperature of these materials.