Scaling InP photonics to 150 mm_ Hot ESC etching for high volume manufacturing

Thanks to advances in InP substrate and epitaxial growth technology, 150 mm InP wafers have become commercially available in recent years. Scaling to the 150 mm wafer size is one of the most effective approaches to reducing the cost of InP photonic devices. In this paper, we demonstrate our newly developed InP etching results on 150 mm wafers using the PlasmaPro100 Cobra300 system equipped with a hot electrostatic clamping (ESC) system. After process development, we achieved a vertical profile with an etch rate exceeding 500 nm/min and a uniformity better than ±3%. Importantly, the sidewall and bottom surfaces-both critical for photonic devices-are very smooth.