| 摘要 |
PROBLEM TO BE SOLVED: To provide a dry etching method for isotropically etching silicon nitride with high selectivity with respect to silicon oxide or silicon.SOLUTION: A silicon nitride film formed on a main surface of a wafer 102 is removed by the dry etching method using plasma 112. A process gas introduced into a processing chamber 101 provided in a plasma etching apparatus M1 is either a first mixed gas containing CFgas, Hgas and COgas, or a second mixed gas containing CFgas, Hgas and COgas. The temperature of a sample table 103 is 40 to 150°C (inclusive). Power of a high-frequency bias supplied from a high-frequency bias power supply 109 to the sample table 103 is higher than 0 W and not higher than 5 W. |
