| 摘要 |
PURPOSE:To enable a preferable deep trench in good shape and reproducibility to be efficiently formed with high precision by a method wherein the mixed gas comprising a bromine containing gas, a halogen element containing gas and nitrogen gas is used as an etching gas of a silicon substrate. CONSTITUTION:A silicon substrate 308 is dry etched away using the mixed gas comprising a bromine containing gas, a halogen element containing gas and nitrogen gas. At this time, the flow rate of nitrogen gas is specified to have a specific ratio to that of the bromine containing gas for controlling the etching rate and the inclination of the deep trench. For example, an RIE device as shown in figure is used so that the Si substrate 308 may be arranged on a lower electrode 305 to lead-in an etching gas comprising HBr, SF6 and N2 from a gas leading-in port 302 for exhausting the etching gas from an exhaust port 303. Finally, the space between electrodes 304, 305 is fed with a power of 13.56MHz from a high frequency power supply 306 to produce gas plasma in the same space between the electrodes 304, 305 for etching away the Si substrate 308.
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