With the progress of technology, large capacity and scalable are required for the future. Recent years, the physical limit is approached and a next-generation memory
is needed in the future. In addition, non- volatile memory occupies more than 96% in the memory market, and RRAM has great advantages such as simple structure,
high scalable, low operation voltage, high operation speed, high endurance and retention. That is the reason RRAM is the candidate in the next generation.
In this experiment, multi-sputtering was used to deposit Zr:SiO 2 and Pt on TiN bottom electrode. The sandwich structure was metal/insulator/metal (MIM). With the different dielectric constant material, a different electrical field will be produced. And then I-V measurement and materials analysis were used to investigate the
characteristic of the RRAM. At first, a forming process is required to the RRAM. The device was swept from negative to positive voltage and obtained the conduction mechanism from curve fitting. The different dielectric constant materials were used to fabricate the RRAM. High and low dielectric materials were HfO 2 and BN, respectively. The electric field distribution is centralized in low dielectric material so the electrons will drift to the direction of electric field. Hence, the Vset will be centralized and more stable. We also fabricated a Zr:SiO 2 /C:SiO 2 RRAM as an high K and low K material. The current fitting results that a hopping conduction occurs in low resistive state (LRS)
and high resistive state (HRS). Both from Raman spectrum and FT-IR spectrum, a graphene oxide was existed in the C:SiO 2 thin film. While the filament was form, the tip of the filament will approach the graphene oxide because of the point effect. Hence, the resistance switching will happen in the grapheme oxide and set voltage will be more stable and lower the operated current. Next, an ICP treatment was used in order to "burn" the carbon in SiO 2 . The purpose is to make an extremely low K material and ignore the effect of the existence of carbon. From the FT-IR spectrum, the carbon signals were disappeared after the ICP oxygen plasma treatment. In the I-V fitting diagram, space char limit results in the high voltage region. The electrical field simulation was an auxiliary tool which shows a strong electrical field occurs in the extremely low K area. While the electrons flow through the conduction path, they will be confined in the porous area. The operation current will decrease because of the limited conduction area.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0825112-173708 |
| Date | 25 August 2012 |
| Creators | Pan, Yin-chih |
| Contributors | Der-shin Gan, Tsung-Ming Tsai, Ting-Chang Chang |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0825112-173708 |
| Rights | user_define, Copyright information available at source archive |
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