[TuP3A] Epitaxy and process

[TuP3A-09] Optimization of Plasma Etching on 150 mm Indium Phosphide Wafers

〇Tom Simpson¹, Jay Burnett², Adam S. Beachey², Jacob Mitchell², Kerry Roberts², J. Iwan Davies³, Huma Ashraf², Samuel Shutts^1,4 (1. School of Physics and Astronomy, Cardiff Univ. (UK), 2. KLA Corp. (SPTS Division) (UK), 3. IQE plc. (UK), 4. Inst. for Compound Semiconductors, Cardiff Univ. (UK))

Indium phosphide based devices are becoming increasingly prevalent for a wide range of applications such as telecommunications, gas sensing and lidar, leading to larger wafer sizes up to diameters of 150 mm being produced. These larger wafers increase throughput and drive down costs but introduce fabrication challenges such as plasma etching of anisotropic and defect-free ridge waveguides. In this work we showcase a new 150 mm high operating temperature electrostatic chuck (ESC) for etching both flatted and notched wafers at over 200 °C . We also show how the ESC temperature, passivating gases and platen power can be used to tune the profile, micro-trenching and footing of these structures. Full-wafer transfers and development was performed on both low open area and high open area masks yielding cross-wafer uniformities of ±3.63 % and ±3.38 % respectively with ansiotropic, defect-free profiles. These ridge waveguides are designed for the realization of conventional (1530 - 1565 nm) and long-wavelength (1565 - 1625 nm) band lasers.