| 摘要 |
PURPOSE:To reduce the damage of a wafer by providing an elevationally movable RF application electrode between a wafer placing electrode and an electrically grounded opposite electrode, and generating a plasma between the opposite electrode and the RF application electrode. CONSTITUTION:A meshlike RF application electrode 8 having an elevationally moving mechanism 11 is provided between a wafer placing electrode 2 and an opposite electrode 3 disposed oppositely to the electrode 2 and electrically grounded, and a DC bias is applied to the electrode 2. An RF plasma is formed between the electrode 3 and the electrode 8, and an ion sheath layer is generated on the electrode 8. Reactive gas ions dissociated by the plasma are accelerated by the ion sheath layer, passed through the mesh of the electrode 8 to arrive at a wafer 5 on the electrode 2 to etch the wafer. Thus, since the wafer 5 is not directly exposed with the plasma and ion energy is controlled by the DC bias, the damage of the wafer can be reduced to perform a preferably dry etching.
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