Sains Malaysiana: 38(3):  295-298 (2008)

Reliability Issues of Bottom-Contact Pentacene Thin-Film Transistors

(Isu-isu Kebolehpercayaan Transistor Filem Nipis Pentasen dengan Sentuhan Bawah)

Jong Duk Lee

Inter-University Semiconductor Research Center (ISRC)

and School of Electrical Engineering

Seoul National University

Byung-Gook Park and Keum-Dong Jung

San 56-1, Sillim-dong, Gwanak-gu, Seoul 151-742

Republic of Korea

ABSTRACT

Bottom-contact pentacene OTFTs are fabricated using cross-linked poly(vinyl alcohol) (PVA) insulator and its reliability characteristics are analyzed. The hysteresis of the OTFTs is mainly caused by the electrons that are injected from the gate electrode to the cross-linked PVA insulator. To block the injection of electrons, plasma-enhanced chemical vapor deposition (PECVD) SiO₂ layer is inserted between the gate electrode and the cross-linked PVA layer, so that the minimum hysteresis can be obtained. In addition, the effects of the gate bias stress as a function of time is investigated to examine the long-term reliability of the device during the operation.

Keywords: Organic thin-film transistors, OTFT, bottom-contact, reliability, hysteresis

ABSTRAK

Pentasen dengan sentuhan bawah OTFT telah difabrikasi dengan menggunakan penebat poli(vinil alkohol)  (PVA) rangkaian silang.  Ciri-ciri kebolehpercayaannya telah dianalisis.  Histeresis dalam OTFT sebahagian besarnya disebabkan oleh elektron yang disuntik daripada elektrod get ke penebat rangkaian silang PVA. Untuk menghalang suntikan elektron, lapisan SiO₂ yang didepositkan melalui kaedah wap kimia terbantu plasma (PECVD) diselitkan antara elektrod get dengan lapisan rangkaian silang PVA supaya  histeresis adalah minimum.  Disamping itu kesan tegasan dari pincangan get sebagai fungsi suhu dikaji untuk mengetahui kebolehpercayaan peranti semasa operasi dalam masa yang panjang.

Kata kunci:  transistor filem nipis organik; OTFT; sentuhan bawah; kebolehpercayaan; histeresis  

REFERENCES/RUJUKAN

Baude, P. F., Ender, D. A., Haase, M. A., Kelley, T. W., Muyres, D. V. & Theiss, S. D. 2003. Pentacene-based radio-frequency identification circuitry. Appl. Phys. Lett. 82: 3964-3966.

Dimitrakopoulos, C. D. & Malenfant, P. R. L. 2002. Organic Thin Film Transistors for Large Area,  Electronics. Adv. Mat. 14: 99-117.

Lee, C. A, Park, D. W., Jin, S. H., Park, I. H., Lee, J. D. & Park, B.-G.2006. Hysteresis mechanism and reduction method in the bottom-contact pentacene thin-film transistors with cross-linked poly(vinyl alcohol) gate insulator. Appl. Phys. Lett. 88: art. no. 252102.

Mizukami, M., Hirohata, N., Iseki, T., Ohtawara, K., Tada, T., Yagyu, S., Abe, T., Suzuki, T., Fujisaki, Y. Inoue, Y. Tokito, S. & Kurita, T.  2006. Flexible AM OLED Panel Driven by Bottom-Contact OTFTs. IEEE Electron Device Lett. 27: 249-251.

Park, D.-W., Lee, C. A., Jung, K.-D., Park, B.-G., Shin, H. & Lee, J. D. 2006. Low hysteresis pentacene thin-film transistors using SiO2/cross-linked poly(vinyl alcohol) gate dielectric. Appl. Phys. Lett. 89: art. no. 263507.

Sekitani, T., Iba, S., Kato, Y., Noguchi, Y., Someya, T. & Sakurai, T. 2005. Suppression of DC bias stress-induced degradation of organic field-effect transistors using postannealing effects. Appl. Phys. Lett. 87:  art no. 073505.

Someya, T., Sakurai, T., & Sekitani, T. 2005. Flexible, large-area sensors and actuators with organic transistor integrated circuits. IEEE International Electron Device Meeting Technical Digest 4-7.

Song, D. H., Choi, M. H., Kim, J. Y., Jang, J. & Kirchmeyer, S. 2007. Process optimization of organic thin-film transistor by ink-jet printing of DH4T on plastic. Appl. Phys. Lett. 90: art. no. 053504.