Browsing by Author "Chu, C. H."

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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.
;
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.
Understanding of the leakage components and its correlation to the oxide scaling on the SONOS cell endurance and retention
(2006)
Chen, C. H.
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Chiang, P. Y.
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Chung, Steve S.
;
Chen, Terry
;
Chou, George C. W.
In this paper, the ONO layer scaling and the leakage components in a SONOS cell have been extensively studied. The reliability with focus on both endurance and data retention has been demonstrated. Results have shown that the cell with thinner blocking oxide has better endurance, while it has poorer data retention. However, this can be achieved by a good control of the oxide quality. In terms of the data retention, thermionic and direct tunneling, in relating to the charge loss, are the two dominant leakage components, which can be separated. Moreover, after cycling, we can separate another third leakage component, the trap-to-trap tunneling induced leakage. These results are useful toward an understanding of the leakage mechanisms of SONOS cell as well as the scaling design of ONO layers.