Patent ID: 6093640
Filing Date: 2000-07-25
Classification: G03F,H01L,Y10S

Abstract:
A method for forming an outer box for box-in-box alignment with an inner box, within a damascene process, comprising:providing a partially completed integrated circuit, including first level wiring;depositing a first dielectric layer, having an upper surface;etching a wiring channel in said upper surface, to a first depth;etching a rectangular trench, corresponding to said outer box, in said upper surface to a second depth that is greater than said first depth;depositing a metal layer to a thickness sufficient to just overfill the wiring channel;planarizing the upper surface until metal in the wiring channel is flush with said upper surface, thereby forming a damascene connector;depositing an inter-metal dielectric layer over said planarized surface, thereby forming a depression over the rectangular trench and making the outer box easier to see;laying down a layer of photoresist;aligning an image of the inner box within the outer box; andexposing and developing the photoresist.