Inductively coupled plasma etching system and switching-type matching device thereof

Abstract

The invention discloses an inductively coupled plasma etching system and a switching-type matching device thereof. The switching-type matching device includes a RF power input port, a RF power outputport, a matching network, and a switching unit. The RF power input port is coupled to the RF power output port through the matching network, or directly coupled to the RF power output port by the switching unit. Because the output impedance of the matching network matches the load impedance of the inductively coupled plasma etching system in a cleaning mode, in the cleaning mode, the switching unit is switched synchronously, so that the RF power input port is coupled to the RF power output port through the matching network so as to increase the power of the RF power, reduce the reflected powerand improve the cleaning efficiency.

Description

technical field [0001] The invention relates to a matching device for a radio frequency power supply, in particular to a switchable matching device for an inductively coupled plasma etching system. Background technique [0002] Among the current semiconductor 8-inch (about 20.32 cm) metal etching equipment, the Metal Etch decoupled plasma source (Metal Etch decoupled plasma source; Metal Etch DPS) (hereinafter referred to as Referred to as DPS metal etching equipment) mainly, such as Figure 6 As shown, the DPS metal etching equipment 50 has a vacuum chamber 51, a coupling coil 52 and a base 53, wherein the coupling coil 52 is coupled to a first RF power supply 55, and the base 53 is coupled to To a second radio frequency power supply 56, the first and second radio frequency power supplies 55, 56 are controlled by a process controller 54 to inductively couple the radio frequency power generated respectively to the vacuum chamber 51 to excite The vacuum chamber 51 generates ...

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Problems solved by technology

[0003] Since the DPS metal etching equipment 50 will perform different etching processes, a variable frequency RF power supply in the intermediate frequency range (1.75MHz-2.165MHz) is used, and its RF power is dynamically adjusted according to the current etching process, and the output RF power is Direct output to the coupling coil; however, in actual use, the reflected power of the DPS metal etching equipment is about 10-20% of the RF power supply, which still has a considerable gap with the ideal value (below 1%); in short, At present, the reflected power of the DPS metal etching equipment is too large

[0004] In addition, the DPS metal etching equipment must perform a chamber cleaning procedure after several etching processes, that is, start the cleaning mode to remove foreign matter attached to the inner wall of the chamber; generally to speed up the cleaning rate, the frequency conversion RF power supply Adjusted to full power output, but because the reflected power of the variable frequency RF power supply is too large, even with full power output, the cleaning efficiency is still limited, and it is necessary to further improve it

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