| 摘要 |
PURPOSE:To avoid the reduction of a dry etching rate, and to improve the mass- producing capability of a dry etching method by increasing the effective velocity of flow of a gas in the vicinity of the surface of a sample up to specific value or more. CONSTITUTION:When a disc body 12 consisting of a dielectric substance is placed between a high-frequency electrode 10 and a ground electrode 11, BCl3, gas is introduced at a flow rate of 50ml/min from a gas supply port 13, an output from a high-frequency power supply 15 is applied to the high-frequency electrode 10, and Al coated onto Si wafers 14 placed onto the electrode 10 is etched, an etching rate of Al does not depend upon the increase of the number of the samples and a loading effect can be suppressed in the same manner as a flow rate of BCl3 gas is increased and the velocity of flow is accelerated by narrowing a distance between the disc body 12 and the high-frequency electrode 10 up to 2cm or less. Accordingly, the ratio of the velocity of flow of the gas flowing on the surface of the sample to be etched to a diffusion rate in said plasma of molecules, atoms, ions, etc. existing in plasma must exceed 0.2 in general in order to prevent the reduction of the etching rate by the loading effect. |
