Evolution of Structural and Electrical Properties of Plasma Nitrided Silicon Oxynitrides During the Formation Process
| Autor: | Olaf Storbeck |
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| Rok vydání: | 2006 |
| Předmět: | |
| Zdroj: | ECS Transactions. 3:159-168 |
| ISSN: | 1938-6737 1938-5862 |
| DOI: | 10.1149/1.2356275 |
| Popis: | Silicon oxynitrides are widely used as gate dielectrics in order to reduce gate leakage [1] and minimize the influence of boron penetration [2]. In this work the formation of silicon oxynitrides by decoupled plasma nitridation (DPN) of thin RTO grown silicon oxide films varying in thickness and composition was investigated. Non-destructive measurement techniques were used after each processing step as base oxidation, plasma nitridation (PN) and post nitridation anneals (PNA) in inert and oxidizing ambient as well as in hydrogen. Electrical film properties as capacitance equivalent thickness (CET), leakage behavior, flatband voltage (VFB) and interface charge density (QIT) where collected by corona characterization of semiconductors (CoCoS) [3], while structural properties as physical thickness, stoichiometry and spatial nitrogen distribution were investigated by optical ellipsometry and angleresolved X-ray photospectroscopy (AR XPS). Figure 1 and 2 show the evolution of the CET and the QIT of a silicon oxynitride during the formation path, starting with a RT base oxidation until a final hydrogen passivation process (PMA). Figure 1 reveal the reduction of the CET during the plasma nitridation as well as the increase during the post nitridation oxidation (PNO), while Figure 2 illustrates the strong generation of interface defects during the plasma nitridation and the cure of these traps during the subsequent processes. The influence of the individual process steps will be discussed in detail. |
| Databáze: | OpenAIRE |
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