Elimination of Aluminum Bubble Defects from Interconnect Metal lines for 0.13μm Memory Devices

摘要

This paper describes a problem faced with Aluminum interconnect lines during the development of the O.l3μm memory device (with three levels of metal stack). For this technology metal lines consist of Titanium as an under layer followed by an AlCu interconnect slab with Titanium Nitride (TiN) as an ARC layer. Connection between different metal levels was done through the tungsten plug technology of 0.31μm vias. In this work, the influence of substrate like Pre-Metal-Dielectric layer and Titanium thickness on the metal film growth was evaluated. Different process levels were screened by using defect inspection tools. Scanning Electron Microscope (SEM) was used for defect imaging and AFM measurement tool was used for surface morphological characterization. The impact from each variable was analyzed in detail.