Patent ID: 6893971

Claim:
A dry etching method comprising: feeding a mixed gas of hydrogen iodide gas and a gas selected from the group consisting of inert gas, gas containing Cl 2 , gas containing BCl 3 , gas containing HBr and gas containing HCl into a reaction chamber and exhausting gas from said reaction chamber such that a pressure within said reaction chamber is controlled to be less than a predetermined pressure; generating plasma from said mixed gas within said reaction chamber by applying at least 13.56 MHz high-frequency power to a flat spiral discharge coil facing an InP-based compound semiconductor substrate positioned on a substrate electrode within said reaction chamber; and using said plasma to etch said InP-based compound semiconductor substrate while controlling a density of said plasma via said high-frequency power applied to said flat spiral discharge coil and while independently controlling ion energy reaching said InP-based compound semiconductor substrate by applying a high-frequency voltage to said substrate electrode via a high-frequency power source.