| 摘要 |
<p>The acid copper sulfate solutions used for electroplating copper circuitry in trenches and vias in IC dielectric material in the Damascene process are replaced with a type of plating system based on the use of highly complexing anions (e.g., pyrophosphate, cyanide, sulfamate, etc.) to provide an inherently high overvoltage that effectively suppresses runaway copper deposition. Such systems, requiring only one easily-controlled organic additive species to provide outstanding leveling, are more efficaceous for bottom-up filling of Damascene trenches and vias than acid copper sulfate baths, which require a minimum of two organic additive species. The highly complexed baths produce fine-grained copper deposits that are typically much harder than large-grained acid sulfate copper deposits, and which exhibit stable mechanical properties that do not change with time, thereby minimizing 'dishing' and giving more consistent CMP results. The mechanical properties and texture of the fine-grained deposits are also much less substrate dependent, which minimizes the effects of variations and flaws in the barrier and seed layers. The resistivity of pyrophosphate and annealed acid sulfate copper deposits are approximately equivalent.</p> |
