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18 September 1995 Evaluation of contaminant-induced charge from oxide chemical-mechanical polish
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The role of chemical-mechanical polishing (CMP) of ILD and metal layers is increasing as device densities in the ULSI shrink. However, the advantages in film planarization gained with CMP are often offset by contaminants which are abundant in the chemical bath (known as the slurry) to which the wafers are exposed during processing. Such chemistries particularly metallic ions can adversely effect device reliability and performance if left on the wafer or ILD in large densitites. The problem we address is that of detecting such residual contaminants post-CMP on product wafers nondestructively. In this work we look at the effects of ionic residuals in ILD oxides before and after exposure to various methods of CMP. Using an optical methodology known as contact potential differentiation in which the potential across the oxide is separated out from (and compared with) a standard surface barrier measurement, we can passively examine any dramatic charge on the wafer and in the oxide as a result of this process. In this paper this technique will be demonstrated on several CMP samples illustrating the contaminant effects on CMP oxides with results compared to chemical spectroscopy.
© (1995) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Peter Burke, John K. Lowell, and Lubek Jastrzebski "Evaluation of contaminant-induced charge from oxide chemical-mechanical polish", Proc. SPIE 2638, Optical Characterization Techniques for High-Performance Microelectronic Device Manufacturing II, (18 September 1995);

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