| 摘要 |
<p>A plasma etching apparatus comprises a chamber (2) for accommodating a semiconductor wafer (W); an upper electrode (21) and a lower electrode (susceptor) (5) provided in the chamber (2); a first high-frequency source (100) for applying high-frequency power of frequency higher than 50 MHz to the upper electrode (21); a second high-frequency source (200) for producing a 2 MHz or higher frequency that is lower than the frequency of the first high-frequency source (100) and supplied the upper electrode (21) and the lower electrode (5) substantially in opposite phase; an exhaust device (35) for maintaining the chamber (2) at a low pressure; and a process gas supply (30) for introducing process gas to the chamber (2). The high-frequency power applied to the upper electrode (21) by the second high-frequency source (200) serves to form a thicker plasma sheath on the upper electrode (21).</p> |
