Transformer coupled capacitive tuning circuit with fast impedance switching for plasma etch chambers

摘要

A transformer coupled capacitive tuning (TCCT) circuit for an inductively coupled plasma (ICP) chamber includes a matching circuit including a first switched capacitor circuit and a first inductor. The first switched capacitor circuit includes a first terminal, a second terminal, a first capacitor connected to at least one of the first terminal and the second terminal, a second capacitor connected to at least one of the first terminal and the second terminal, and a first switch in communication with at least one of the first capacitor and the second capacitor to vary a capacitance value between the first terminal and the second terminal. A power splitter communicates with the matching circuit and an inductive coil of the ICP chamber.

主权项

1. A transformer coupled capacitive tuning (TCCT) circuit for an inductively coupled plasma (ICP) chamber, comprising:
a matching circuit including: a first switched capacitor circuit and a first inductor, wherein the first switched capacitor circuit includes:
a first terminal connected to an RF input;a second terminal;a first capacitor connected to at least one of the first terminal and the second terminal;a second capacitor connected to at least one of the first terminal and the second terminal; anda first switch in communication with at least one of the first capacitor and the second capacitor to vary a capacitance value between the first terminal and the second terminal; and a second switched capacitor circuit including:
a third terminal connected to the second terminal of the first switched capacitor circuit;a fourth terminal connected to the first inductor;a third capacitor connected to at least one of the third terminal and the fourth terminal;a fourth capacitor connected to at least one of the third terminal and the fourth terminal; anda second switch in communication with at least one of the third capacitor and the fourth capacitor to vary a capacitance value between the third terminal and the fourth terminal; and the TCCT circuit further comprising: a fifth capacitor, wherein a first terminal of the fifth capacitor is connected to the second terminal of the first switched capacitor circuit and to the third terminal of the second switched capacitor circuit, and wherein a second terminal of the fifth capacitor is connected to ground; and a power splitter in communication with the matching circuit and an inductive coil of the ICP chamber.