Alchimer, provider of nanometric film deposition for advanced 3D packaging applications as well as semiconductor interconnects, MEMS and other electronic technologies, announced a new wet-deposition process, AquiVantage, that grows interconnect layers for interposer redistribution layers (RDLs) and significantly enhances via-last backside wafer interconnects.
AquiVantage uses the same cost-saving technology as Alchimer’s wet processes for through-silicon vias (TSVs). It provides extremely high-quality films, while also eliminating several process steps, including two costly photolithography steps. It therefore marks a fundamental shift in the construction of interposer for 3D chip packages. Overall, interposer cost savings of more than 50 percent are achievable with AquiVantage; in addition, the technology accommodates thicker wafers, eliminating the need for wafer carriers and allows for highly scalloped viastructures and faster etching times, allowing users to gain cost advantages.
AquiVantage is also well suited for via-last 3D packaging process flows, with similar savings in complexity and cost.
Interposers, an intermediate connecting layer between stacked-chip packages and printed circuit boards, are key to the migration of 3D packaging into high-volume production. They provide a reliable interface for data, power, and other connections between increasingly complex packaged semiconductors and the circuit boards that serve as the backbone of smartphones, tablet computers, and other electronic systems.
Interposers incorporate a TSV structure, as well as front-side redistribution circuitry (for attachment to the chip stack) and back-side redistribution and bumping (for attachment to the circuit board).
The AquiVantage process provides concurrent wet deposition of TSV and front-side isolation, barrier, and copper fill/RDL, while eliminating CMP and dry deposition steps. It also supports smaller vias with higher aspect ratios. On the backside, the AquiVantage process allows selective maskless growth of the on-silicon isolation layer, completely eliminating an entire expose/develop/etch/clean lithography-process cycle.
AquiVantage offers significant potential for cost savings and improved margins at multiple levels of the supply chain, from IDMs to OSATs and foundries. In addition to savings from process simplification, there are also significant economies from eliminating several dry-process tools and their associated cleanroom space, infrastructure and power consumption.
“This extension of our product suite is another step towards Alchimer’s goal of providing the electronics industry with its first truly new metallization alternative in decades. We are applying fundamental molecular-materials science to the grand challenges of cost and film quality, and are now able to offer a unified approach to film deposition that can extend all the way to wafer bumping,” said Alchimer CEO Steve Lerner. “We are confident that AquiVantage can have a tremendous positive impact on the business models of manufacturing enterprises all along the electronics value chain, through simplification, economy, efficiency, and environmentalresponsibility.”