Memory Device
Chapter 4 Conclusion and Future Work
4.1. Conclusion
In my thesis, we introduced several kinds of non-volatile memory in the first chapter.
In second chapter, we introduce the device with a single-layer structure sandwiched between two metal electrodes. The I-V characteristic and the probable mechanism in this structure have presented, too. We believe that the current through the device changed from a charge injection current to a ohmic conduction current by the Schottky, Poole Frenkel, and ohmic model.
Later, a new structure device with Al /Alq3 deposited on n-type Si substrate is investigated. A similar bistable behavior that is described in third chapter are found.
Two conducting states at the same bias are obtained in the current-voltage curve and it shows an on/off current ratio about 104. Moreover, the formation of the bistable states is suggested to be caused by electron trapping in the defects at the Schottky junction and at the heterojunction under electrical field stressing conditions. In addition, We
also show a promise result for thermal deposition with controllable film quality by
varying deposition rate and film thickness.
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4.2. Conclusion
In the future, there are still many problems about organic nonvolatile memory to discuss and develop, and we list some of them.
1.
Mechanism of organic memory.Ensure and modify our suggestion, and use computer to simulate the mechanism in the future.
2.
Change other material and surface treatmentWe will change our organic material, such as pentacene or other polymer. We also can change our deposited method, such as spin coating. In other aspect, we may improve the effect of memory by surface treatment. Many groups have researched organic surface treatment to enhance OTFT performance. Hence, we can imitate those method to enhance our memory performance.
3. The encapsulation of the organic bistable memory
Aqueous vapor and oxygen in the air may break the memory effect. To hope to lengthen the life-time of the memory, we should study the encapsulation in the future.
4. Finally, we will combine organic memory into OLED, to realize a device that can bright when the memory stores data.
53
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Vita
Szu-Yuan Chen was born at 08, Nov. 1982 in Taipei City, Taiwan.
He recevied the B.S. degree in engineering and system science from National Tsing Hua University, Hsinchu, Taiwan in 2005. The M.S.
degree will receive in department of photonics and display institute from National Chiao Tung University, Hsinchu, Taiwan in 2007.
His research include semiconductor and the analysis and fabrication of organic bistable memory devices.
Publications：
[01] S. Y. Chen, T. Y. Chang, and P. T. Lee, “Bistable Characteristics of the Organic Device with Heterojunction,” O3.11, MRS’07 Spring Meeting, San Francisco, CA, USA (2007)
[02] T. Y. Chang, S. Y. Chen, and P. T. Lee, “Investigation of Deposition Rate Effect on the Current-Voltage Characteristics of Organic Dynamic Random Access Bistable Devices,” p.19, SID’07, Long Bench, CA, USA (2007)
[03] P. T. Lee, T. Y. Chang, and S. Y. Chen, “Investigation of Electrical Pulse Erasing Method Effect on Current-Voltage Characteristics of Organic Bistable Device,” IDMC’07, Taipei, Taiwan (2007)