Silicides as contact material for DRAM applications
| Autor: | Audrey Dupont, Clemens Fitz, Matthias Goldbach, S. Schmidbauer |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Dynamic random-access memory
Materials science Silicon business.industry Contact resistance chemistry.chemical_element Nanotechnology Condensed Matter Physics Salicide Atomic and Molecular Physics and Optics Surfaces Coatings and Films Electronic Optical and Magnetic Materials law.invention Semiconductor chemistry law Optoelectronics Metallizing Electrical and Electronic Engineering business Dram Leakage (electronics) |
| Zdroj: | Microelectronic Engineering. 82:460-466 |
| ISSN: | 0167-9317 |
| Popis: | TiSi, CoSi, CoSi"2 and NiSi are used for a salicide contact metallisation in DRAM devices. The contact resistance is studied: for contacts to tungsten silicide-gates, for self-aligned n-type contacts in the memory cell array and for large borderless n-type and p-type contacts in the chip periphery. It is shown that the contact resistance on p-type contacts is reduced with CoSi by at least 40% compared to TiSi and NiSi, whereas the contact resistance of cell array-, gate- and n-type contacts is comparable for the different silicides. In order to enable a sufficient retention time the leakage current is critical. Due to the low silicon consumption NiSi contacts result in the smallest leakage. Using a Cobalt+Ti-Cap stack the Si leakage currents rise by orders of magnitude. It is shown that with a TiN-cap and a changed chemistry for the selective strip leakage currents as small as for TiSi can be achieved. The role of CoSi-thickness and the formed silicide-phase, i.e., CoSi or CoSi"2, on contact resistance and leakage current are discussed. |
| Databáze: | OpenAIRE |
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