Accurate dry etching technique for germanium waveguide by using CHF3 based inductively coupled plasma

A CHF3 inductively coupled plasma (ICP) based dry etching method is proposed for accurate etching of Ge waveguides. CHF3 ICP based dry etching produces excellent anisotropy along with good selectivity with regards to regular polymeric photoresist, which leads to the elimination of under-cut. As a result, an almost vertical sidewall angle of 85° with an etching rate of 190 nm/min was realised with ...