Metal etch in advanced immersion tank with precision uniformity using agitation and wafer rotation
Semiconductor wafer fabrication involves etching to remove unwanted material, crucial for metal film patterning and interconnects. Etching methods include dry etching, de-plating, and dissolution on substrates like silicon, GaAs, and sapphire. Dry etching offers precise, anisotropic channel creation but requires costly, complex tools. De-plating electrochemically removes metal, providing better uniformity than immersion methods. However, it's expensive and low throughput. Immersion etching, using chemical baths, faces decline due to isotropic etching and poor uniformity. While dry etching remains crucial for critical features, improved immersion methods seek application for less critical tasks. A study designs an immersion etch tank for better uniformity and tests it with gold and copper etching solutions.