High Etch Rate Reactive Ion Etching Process for Indium Tin Oxide

A high indium tin oxide etch rate, i.e., 1630 A/min, reactive ion etching condition has been obtained. This process is based on the combination of high temperature, i.e., 250degreesC, and a mixture of HCI and CH4 gases. Throughout the whole range of the gas composition, i.e., from 100% HCI to 100% CH4, the highest etch rate is obtainable in a small CH4 concentration range, e.g., around 40%. The same phenomenon has been observed at different plasma powers. The influence of temperature of power to the etch rate is not obvious unless a threshold temperature or a threshold power is surpassed. The HCI/(40%) CH4 etched surface has a smooth topography and an In/Sn ratio similar to that before etch. Surface reactions of the high etch rate process are different from those of the low etch rate process.