Novel Bonding Interfacial Material for Carrier Wafer of BSPDN & Reconstructed D2W Integration

Novel carrier wafer system with permanent bonding is required for the advanced 3D architectures e.g. backside power delivery network and reconstructed Die-to-Wafer hybrid bonding. Robust bonding should be achieved with inorganic bonding dielectric material with several properties, such as better thermal conductivity. The conventional bonding material, such as SiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> or SiCN does not meet these demands. Hence, we adopted the newly developed Al<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> deposited by ALD, which has higher thermal conductivity. The excellent quality of the bonding interface was confirmed without CMP and activation, which is an innovative progress for the carrier wafer bonding in terms of cost-reduction. Moreover, this study gives some insight into bonding mechanisms of Al<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf>. Furthermore, Al<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> achieved over 100W/(mK) by under 125°C ambient, and 10~20W/(mK) higher thermal conductivity than SiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> consistently.