Inductively Coupled Plasma Processing Chamber with Automatic Frequency Tuning Source and Bias RF Power Supply

Abstract

The invention discloses an inductance coupling plasma processing chamber of an automatic frequency tuning source and a bias radio frequency power source. The inductance coupling plasma processing chamber comprises a processing chamber body, a source radio frequency power source and a bias radio frequency power source, a cathode is arranged at the bottom of an inner cavity of the processing chamber body, a plurality of source coils are arranged at the top of the inner cavity of the processing chamber body, a circuit of the source radio frequency power source is connected with the source coils, a circuit of the bias radio frequency power source is connected with the cathode, the source radio frequency power source and the bias radio frequency power source can realize automatic frequency tuning and can respond to and match with changes of load resistance, the circuit between the source radio frequency power source and the source coils is connected with a matching circuit, the circuit between the bias radio frequency power source and the cathode is connected with a matching circuit, the matching circuit are fixed, the processing chamber body comprises a detection circuit for detecting the load resistance and a control circuit in circuit connection with the detection circuit, and the source radio frequency power source and the bias radio frequency power source are correspondingly in circuit connection with control circuits respectively. The source radio frequency power source and the bias radio frequency power source have functions of automatic frequency tuning, and the source radio frequency power source and the bias radio frequency power source input into the processing chamber body through frequency sweeping and electric tuning are high in tuning speed and wide in tuning range.

Description

technical field [0001] The invention relates to wafer processing equipment in the field of semiconductors, in particular to an inductively coupled plasma processing chamber with an automatic frequency tuning source and a bias radio frequency power supply. Background technique [0002] Currently, an inductively coupled plasma (ICP, inductively coupled plasma) processing chamber (processing chamber) is applied to a through silicon etching process (TSV) in semiconductor wafer processing. The conventional inductively coupled plasma processing chamber adopts fixed frequency radio frequency power (fixedfrequencyRFpowers) and fixed frequency low frequency power (fixedfrequencyLFpowers). In order to match the load impedance of the plasma processing chamber, the fixed-frequency radio frequency power supply or the fixed-frequency low-frequency power supply in the prior art needs to be separately connected to an automatically tuned impedance matching circuit (automatch), and continue t...

AI Technical Summary

Problems solved by technology

[0004] 1. The fixed-frequency RF power supply and the fixed-frequency low-frequency power supply need to be equipped with two variable vacuum capacitors in the impedance matching circuit, which has a complex structure and high cost;

[0005] 2. The capacitance value of the variable vacuum capacitor is tuned mechanically by a stepping motor, the tuning speed is slow, and the tuning range is narrow;

However, in the prior art, a stepper motor is used to mechanically tune the capacitance value of the variable vacuum capacitor, and its tuning speed is slow, and the speed of mechanical tuning cannot keep up with the impedance state of the processing chamber required by the Bosch method in two or three short-term process steps per cycle. The change speed of the process chamber is difficult to achieve load impedance matching;

[0007] 4. Due to the use of stepping motors to mechanically tune the capacitance value of the variable vacuum capacitor, the tuning speed is slow and cannot keep up with the changes in the load impedance of the processing chamber. The phase of the RF power supply will generate reflected power and reduce the working efficiency of the processing chamber

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