Electrolytic gold deplating is a precision wet-processing technology used to selectively remove exposed gold seed layers after electroplating for feature isolation. The Solstice® platform delivers highly uniform, tightly controlled gold removal with minimal undercut, low surface roughness, and exceptional process repeatability. Compared to conventional dry etch methods, Solstice provides a lower-cost, higher-throughput solution that preserves critical feature dimensions while integrating plating,deplating, and surface preparation on a single automated platform. Our highly stable, cost-effective electrodeposition process is ideally suited for use in forming features such gold bond pads or gold bumps. A subsequent photoresist strip step is followed by the removal of the original gold seed, otherwise known as feature isolation. This feature isolation step can be performed using dry etch in a vacuum chamber, but that process is expensive and results in a roughened surface of the plated feature. Electrolytic gold deplate is a much lower-cost option that results in minimal CD loss and the smoothest possible gold surface. Applications - Bond pads for microLEDs - VCSEL p- and n-contact plating - Gold bump - BAW and SAW filters - Air-bridge - And more… Features - Precision wafer rotation, closed loop flow control - Voltage-controlled recipe construction - Continuously filtered chemistry loop - Optional carbon filtration - Adjustable diffuser - Wet-contact plating rotor, customized contact reach - Levitronix® pump with LeviFlow™ Benefits - Extremely uniform removal - Optimal, responsive removal rate - Extremely uniform field profile - Contact reach aligns to existing integration - Accurate, precise flow rate control Technical Data Wafer Materials: Silicon, GaAs, GaN on Si, GaN on Sapphire, Sapphire, Transparent substrates and more Flow Rate: 30 lpm Plating Rate: Up to 150μm/minute Within-Wafer Uniformity: <3% (range 2*mean) CD Reduction: <0 2Å on 1200Å seed deplate Within-Wafer Uniformity: <2% Within Feature Uniformity: <2% Roughness: 3A Ra
