Emission Spectrochemical Analysis in Dry Etching Process of InP by Cl2 Inductively Coupled Plasma

We carried out a diagnostic study of the Cl 2 inductively coupled plasma (ICP) etching process by means of spectrochemical analysis using a narrow-field optical fiber probe. Many elements including etching products such as Cl + , Si, In and SiCl x were observed in the etching plasma. It was found that the state of the plasma is strongly dependent on the monitoring distance normal to the sample. To stabilize the dry etching process, it is important to monitor the plasma at the spot of the reaction between sample and plasma.