HIGH-SPEED ETCHING OF INDIUM-TIN-OXIDE THIN-FILMS USING AN INDUCTIVELY-COUPLED PLASMA

The dry etching of indium-tin-oxide (ITO) films using a high-density i nductively coupled rf plasma is described. Various etching characteris tics are examined for an etching gas of CH4/H-2 mixture. A very high e tching rate of ITO films of over 200 nm/min was obtained at 100% CH4, while the high etching rate of similar to 100 nm/min was achieved even at 100% H-2 with the moderate de self-bias voltage of 300 V. The etch selectivity of ITO to SiO2 and Si3N4 was over similar to 10. The depe ndences of etching rate on substrate temperature and self-bins de volt age suggest that the high-flux ion bombardment given by the inductive rf plasma enhances the etching of ITO films. On the other hand, the cr ystallinity of ITO has a nominal effect on the etching characteristics of ITO films.