Inductively coupled plasma processing system and processing method

Abstract

The present invention provides an inductive-coupling plasma processing system. The processing system comprises a radio frequency power source system; the radio frequency power source system includes a source radio frequency power source system and a bias radio frequency power source system; the source radio frequency power source system includes a source radio frequency power source and a source matching network; the bias radio frequency power source system includes a bias radio frequency power source and a bias matching network; the source radio frequency power source is a frequency-constant power source; the bias radio frequency power source is a frequency-variable power source; the source matching network is an automatic matching network; and the bias matching network is a fixed matching network with wide-frequency band operating performance. With the inductive-coupling plasma processing system provided by the invention adopted, fast and accurate impedance matching between the radio frequency power sources and plasmas can be realized. In addition, the present invention also provides an inductive-coupling plasma processing method.

Description

Technical field [0001] The present invention relates to the field of semiconductor processing equipment, in particular to an inductively coupled plasma processing system and processing method. Background technique [0002] The inductively coupled plasma processing system includes a radio frequency power supply system. Among them, the RF power system includes a source RF power system and a bias RF power system. Among them, the source RF power supply system and the bias RF power supply system both include two parts: the RF power supply and the matching network. Among them, the matching network is used between the radio frequency power supply and the load of the inductively coupled plasma processing equipment to quickly adjust the corresponding parameters according to the change of the load impedance, so that the radio frequency power supply and the changing load are always in an impedance matching state. In the inductively coupled plasma processing equipment, the load is the plas...

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Problems solved by technology

Relatively the worst distribution will be from the input terminal to the output terminal to form a distribution of 2Vp to 0. In this distribution state, the voltage amplitudes at both ends of the inductance coil are seriously unbalanced, which will greatly affect the electromagnetic field in the reaction chamber below. effect, which eventually makes the distribution of the plasma treatment effect below uneven

However, after the automatic frequency modulation technology is applied to the source RF power supply, the output frequency often changes during operation. At this time, the capacitor connected to the output end of the inductor coil cannot keep up with the above-mentioned high-speed changes, and eventually the voltage distribution on the coil cannot achieve a balanced state.

[0005] In addition, when the process is long, the resistance part of the plasma impedance of the inductively coupled plasma processing equipment sometimes changes to a certain extent, but because the resistance part of the matching impedance of the fixed matching network is basically fixed throughout the process, Therefore, the fixed matching network of the RF power system with automatic frequency modulation cannot match the change of the resistance part of the plasma impedance well, so it cannot adjust the impedance matching between the bias RF power supply and the load well, and then it will Generate a certain amount of reflected power

For some processes that require a small value of bias power, such as the Bosch etching process, such reflected power will seriously affect the morphology of the via hole formed by etching

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