Patent ID: 8288287

Claim:
An etching method comprising: etching a trench (a groove) in a silicon substrate patterned by a mask material composed of SiO 2 or a silicon substrate having a silicon oxide dielectric layer and patterned by a mask material composed of SiO 2 , the etching being performed via a plasma generated by a mixed gas formed by adding a HBr gas to a mixed gas composed only of SF 6 gas, O 2 gas and SiF 4 gas, wherein the amount of HBr gas is within a range of 5 to 16% (percent concentration) of the total gas flow rate of said mixed gas composed only of SF 6 gas having a flow rate of 150 mL/min, O 2 gas having a flow rate of 30 mL/min and SiF 4 gas having a flow rate of 200 mL/min, and wherein a temperature of a sample stage for holding the silicon substrate patterned by the mask material composed of SiO 2 or the silicon substrate having the silicon oxide dielectric layer and patterned by the mask material composed of SiO 2 is controlled to 0Â° C. or lower.