Etching method and etching equipment
View Patent ↗The invention provides an etching method for realizing trench etching without causing any damages to the side walls of the trench while maintaining a high-etching rate. The plasma etching method relates to forming a groove or a hole by forming a silicon trench to a silicon substrate or a silicon substrate having a silicon oxide dielectric layer via a mixed gas plasma containing a mixed gas of SF 6 and O 2 or a mixed gas of SF 6 , O 2 and SiF 4 and having added thereto a gas containing hydrogen within the range of 5 to 16% (percent concentration) of the total gas flow rate of the mixed gas.
1. 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 0° C. or lower.
2. The etching method according to claim 1 , wherein the etching is performed using a microwave plasma etching equipment utilizing microwaves and magnetic fields as means for generating a plasma.