| 摘要 |
PURPOSE:To improve the selectivity of etching by setting a wafer to a sufficiently low temperature when selectively dry etching a substance to be etched, increasing the absorption amount of an etchant to accelerate the etching of a silicon oxide film, and accelerating the formation of a film for stopping the etching. CONSTITUTION:With a dry etching apparatus having a high efficiency cooling mechanism and an ion/electron emitting mechanism, a reaction chamber 8 is evacuated in high vacuum, a substance to be etched is then cooled to 0 deg.C or lower, and reactive gases (CF4) 8, 9 containing carbon atoms and fluorine atoms are then applied substantially vertically to a silicon oxide film on the surface of the wafer 4 placed on a supporting plate 13 to etch them. When the etching conditions select 13.56MHz and 2.3W/cm<2> of high frequency power, 0.05Torr of gas pressure and -50 deg.C selected for etching temperature, a high selectivity is obtained. |
