Plasma treatment apparatus and etching method

Abstract

This invention provides a plasma processing apparatus and etching method for promoting free radical transport to form a better etched shape. The plasma processing apparatus of this invention comprises: a plasma processing chamber; a substrate support disposed within the plasma processing chamber and supporting a substrate; a gas supply unit supplying etching gas to the plasma processing chamber; a lower electrode disposed within the substrate support; an upper electrode facing the lower electrode; a power source supplying a source RF signal to the upper electrode or the lower electrode for generating plasma; a first bias power source supplying a first bias signal to the lower electrode; a second bias power source supplying a second bias signal to the lower electrode; and a control unit; the control unit controls the following steps: (a) controlling the source power source to supply the first bias signal to the upper electrode or the lower electrode. (a) The source RF signal of the second power level; (b) Controlling in a manner that repeats steps (b1) and (b2), (b1) controlling the source power supply to supply the source RF signal of the second power level to the upper electrode or the lower electrode, (b2) controlling the source power supply to supply the source RF signal of the third power level to the upper electrode or the lower electrode and controlling the first bias power supply to supply the first bias signal to the lower electrode; (c) Controlling the second bias power supply to supply the second bias signal to the lower electrode; and controlling in a manner that repeats the above-mentioned cycle by taking steps (a), (b), and (c) as one cycle.

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