METHOD AND APPARATUS FOR FLAG-LESS WAFER BONDING TOOL

摘要

Embodiments in accordance with the present invention relate to methods and apparatuses for bonding together substrates (602/604) in a manner that suppresses the formation of voids between them In a specific embodiment, a backside of each substrate (602/604) is adhered to a front area of flexible, porous chuck (606/608) having a rear area in pneumatic communication with a vacuum Application of the vacuum causes the chuck (606/608) and the associated substrate (602, 604) to slightly bend Owing to this bending, physical contact between local portions on the front side of th flexed substrates may be initiated, while maintaining other portions on front side of the substrates substantially free from contact with each other A bond wave is formed and maintained at a determined velocity to form a continuous interface joining the front sides of the substrates, without formation of voids therebetween In one embodiment, the chucks (606/608) may comprise porous polyethylene sealed with polyimide except for a portion of the front configured to be in contact with the substrate, and a portion of the backside configured to be in communication with a vacuum source (614).