(December 15, 2008) BROMONT, Canada and MASSY, France, DALSA Semiconductor, supplier of specialized and custom wafer foundry services announced successful tests creating conformal copper seed layers on through-silicon via structures (TSVs) using the eG ViaCoat process from Alchimer S.A. As a result, DALSA reportedly intends to license Alchimer’s technology to enhance its MEMS production capabilities.
This electrochemical coating process for the copper seed metallization of TSVs used in advanced 3D packaging applications reportedly enables over 50% reduction in cost of ownership compared to dry vacuum processes. According to Luc Ouellet, VP of Technology Development at DALSA Semiconductor, Alchimer’s copper-based approach will allow the company to achieve faster operating frequencies and higher power density with lower resistance and higher thermal dissipation when fabricating low-cost MEMS products. “Alchimer’s approach for TSV is a strategic technology allowing us to mass-produce MEMS devices in cost-sensitive markets,” said Ouellet. DALSA has been using via-first processes for TSV in fabricating MEMS for years, he added.
To secure the license agreement with DALSA, Alchimer says it successfully demonstrated the coverage performance of its product on deep reentrant TSVs. A reentrant TSV is one whose diameter is narrower at the surface of the substrate than at the bottom,a nd is characteristic of faster Bosch deep reactive ion etching (DRIE) processes. By demonstrating consistent step coverage on reentrant structures, eG ViaCoat reportedly allows high-etch-rate Bosch processes to be used, cutting the costs of DRIE steps by up to 50%. These cost savings in the faster DRIE steps are in addition to the cost savings made in the copper seed metallization step. Alchimer also reported that is successfully demonstrated subsequent void-free copper fill on these deep reentrant TSV structures.
Steve Lerner, CEO, Alchimer, expressed excitement for working with DALSA, calling it a “leader in the MEMS foundry business” as well as “a company committed to creating innovative technologies and quality products.”