Reactive ion etching with control of etch gas flow rate, pressure and rf power

摘要

The reactive ion etching process (RIE) includes control of etchant gas flow rate and pressure, and radio frequency (r.f.) power to provide an etch rate and/or level of material re-deposition that reduces the surface and sidewall roughness in the manufacture of optical waveguides to 5-100 nm having an etch depth greater than 10žm. The etchant gas may be fluorine based eg CHFSB3/SB, CSB2/SBFSB6,/SB SFSB6,/SB CFSB4/SB or CBrFSB5/SB used together with a process gas eg OSB2/SB, Ar, CHSB3,/SB CHSB4/SB or CSB2/SBHSB4/SB, with flow rates of 5-75 sccm and 0-15 sccm respectively with an etchant gas pressure of 5-120 mTorr. The power density range may be 0.16-0.95 WcmSP-2/SP.