Iodine Solid Source Inductively Coupled Plasma Etching of InP

We have demonstrated vertical and smooth inductively coupled plasma (ICP) dry etching of InP using solid iodine as a gas source at a low process temperature of 90°C. We prepared a solid iodine crystal in the ICP etching chamber as the etching gas source. Iodine gas was supplied from the solid source at a high vapor pressure into the process chamber. Vertical and smooth etching was realized under the condition of low temperature and low power. The typical etching rate was 0.4 µm/min. We believe that solid I 2 -ICP etching is a very simple and useful process for InP-based device fabrication with a resist mask.