A New Adhesive for CoW Cu-Cu Hybrid Bonding with High Throughput and Room Temperature pre-Bonding
Yasuhisa Kayaba, Yuzo NAKAMURA, Wataru Okada, Takuo Shikama, Kahori Tamura, Satoshi Inada
Abstract
In this report, a new approach to high throughput, low-temperature chip on wafer hybrid bonding processes by using a unique adhesive is described. In our process, a bonding layer consisting of cured adhesive and slightly recessed Cu pads is fabricated on the chip surface, and the chip is bonded to another bonding layer consisting of SiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> and Cu pads fabricated on the target wafer. The chip is pre-bonded to the target wafer under compression for 1 second at room temperature by contacting the adhesive and SiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> . By using the slight film shrinkage of the adhesive in the Cu-Cu bonding process, the two facing Cu contact and compressed. As a result, batch annealing process without chip compression becomes possible. Experimental results for the proof of our process are reported.