Browsing by Author "Lai, E. K."

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A highly reliable self-aligned graded oxide WOx resistance memory: Conduction mechanisms and reliability
(2007-01-01)
Ho, ChiaHua
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Lai, E. K.
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Lee, M. D.
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Pan, C. L.
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Yao, Y. D.
WOx formed by plasmas oxidation shows promising multibit/cell resistance memory characteristics [1]. The simple memory is completely self-aligned, requiring no additional masks and has a small 6F(2) cell size. In this work we introduce a graded oxide device that is highly reliable (250 degrees C baking for > 2,000 hrs). The conduction mechanism and factors affecting the memory reliability are examined extensively.
Insight of stress effect on the ONO stack layer in a SONOS-type flash memory cell
(2006)
Yeh, C. C.
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Liao, Y. Y.
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Wang, Tahui
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Tsai, W. J.
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Lu, T. C.
The stress effect on the ONO stack layer in a two-bit SONOS-type memory cell is investigated. Our results show that P/E cycles induced stress will generate extra nitride, oxide, and interface traps in the ONO stack layer. Besides, these stress created traps are unstable and will be annealed by additional thermal treatment. Storage electrons escape from stress-created nitride and oxide traps and the trap annealing effects are root causes of charge loss in a SONOS cell.
MULTI-LEVEL OPERATION OF FULLY CMOS COMPATIBLE WOX RESISTIVE RANDOM ACCESS MEMORY (RRAM)
(2009)
Chien, W. C.
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Chen, Y. C.
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Chang, K. P.
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Lai, E. K.
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Yao, Y. D.
The multi-level operation of WOX based RRAM has been investigated. Improvement of our WOX process has produced an extended linear R-V region for our devices. By adding an electrical forming process and a program-verify algorithm we have demonstrated stable 2-bit/cell operation, with potential for 3-bit/cell. The reliability of the MLC operation has been examined and very stable high temperature retention, robust read disturb immunity and initial cycling endurance of >1,000 times have been demonstrated.
Unipolar Switching Behaviors of RTO WO(X) RRAM
(2010-02-01)
Chien, W. C.
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Chen, Y. C.
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Lai, E. K.
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Yao, Y. D.
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Lin, P.
The microstructure and electrical properties of the WO(X)-based resistive random access memory are investigated in this letter. The WO(X) layer is formed by converting the surface of the W plug with a CMOS-compatible rapid thermal oxidation process. The conductive-atomic-force-microscopy result indicates that nanoscale conducting channels exist in the WO(X) layer and result in a low initial resistance. This letter studies the unipolar operation-the programming, reading, and reliability behaviors of the device are characterized systematically. The low programming voltages for RESET (3.3 V/50 ns) and fast SET speed (3 V/300 ns) are achieved along with cycling endurance greater than 10(7) times. In addition, the device is immune to read disturb. A 2-bit/cell operation is also demonstrated for high-density applications.
Unipolar Switching Behaviors of RTO WOX RRAM
(2010-02-01)
Chien, W. C.
;
Chen, Y. C.
;
Lai, E. K.
;
Yao, Y. D.
;
Lin, P.
The microstructure and electrical properties of the WOX-based resistive random access memory are investigated in this letter. The WOX layer is formed by converting the surface of the W plug with a CMOS-compatible rapid thermal oxidation process. The conductive-atomic-force-microscopy result indicates that nanoscale conducting channels exist in the WOX layer and result in a low initial resistance. This letter studies the unipolar operation-the programming, reading, and reliability behaviors of the device are characterized systematically. The low programming voltages for RESET (3.3 V/50 ns) and fast SET speed (3 V/300 ns) are achieved along with cycling endurance greater than 10(7) times. In addition, the device is immune to read disturb. A 2-bit/cell operation is also demonstrated for high-density applications.