To meet the needs of reduced form-factor electronics and ever-shrinking die footprint, the long discussed vertical integration of IC's has finally moved into production in semiconductor fabrication.
With this development the need for cost-effective Through-Silicon-Via processes has become increasingly important part of today's state-of-the-art IDM and Foundry capabilities, including ≤200mm production. As the type of devices being integrated into the vertical packages expand smaller diameter, higher aspect ratio vias are needed. This creates increasing challenges for etch and deposition to ensure high reliability, low resistance contacts.
While there films and etch processes are similar to those used in IC manufacturing, optimization is required for these large features (typically 5-25µm). Processes needed include deep reactive ion etch of silicon and oxide films, conformal deposition of dielectric liners and PVD liner/barrier films and void free plug fill.