ABSTRACT
In this study, the rf magnetron sputtering was used to deposit (Ba0.8Sr0.2)(Ti0.9Zr0.1)O3 (BSTZ) ferroelectric thin films on SiO2/Si substrates, and MFIS structure was also fabricated. The effects of various sputtering parameters effects on the characteristics of BSTZ thin films, such as the oxygen concentrations, deposition temperature, rf power, chamber pressure and deposition time were be discussed. As deposited on Pt/Ti/SiO2/Si substrate, the electrical and physical properties of BSTZ thin films after RTA and CTA thermal treatment were be also discussed.
In XRD and SEM analysis, the crystal structure and grain size of as-deposited BSTZ thin film could be observed. From the C-V and J-E curves obtained, the memory window and leakage current density of MFIS structure were about 9.5V and 2.76¡Ñ 10-9 A/cm2, respectively. After RTA and CTA post-treatment, the capacitances of MFM structure were about 2.06nF and 1.93nF. We found that dielectric constant of as-deposited BSTZ thin film increased to 183 and 194, respectively. In addition, the leakage current density of RTA and CTA treated BSTZ films were about 3.82¡Ñ 10-6 A/cm2 and 1.16¡Ñ 10-6 A/cm2.
Finally, the one-transistor-capacitor (1TC) structure of ferroelectric random access memory (FeRAM) with the gate oxide of BSTZ thin films on the polysilicon TFT structure have been fabricated and investigated.From the experimental results, the on/off drain current ratio is two orders, and its value is much smaller than those of the most reported bottom-gated TFTs devices by using different ferroelectric materials as gate oxide. From these results in this study, the BSTZ thin films for top-gate polysilicon thin-film transistor will be an excellent candidate to fabricate higher storage capacitance ferroelectric random access memory (FeRAM) devices for system on panel (SOP) applications.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0725107-165513 |
| Date | 25 July 2007 |
| Creators | Chen, Chih-Sheng |
| Contributors | Ying-Chung Chen, Mau-Phon Houng, Jow-Lay Huang, Wei-Hsing Tuan, Cheng-Fu Yang |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0725107-165513 |
| Rights | campus_withheld, Copyright information available at source archive |
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