Impedance matching network and method

An impedance matching network comprising:

• a radio frequency (RF) input configured to operably couple to an RF source;
• an RF output configured to operably couple to a plasma chamber;
• a mechanically variable capacitor (MVC);
• an inductor coupled in series or parallel to the MVC;
• a second variable capacitor separate and distinct from the MVC;
• a sensor configured to measure a parameter related to the plasma chamber;
• and
• a control circuit operably coupled to the MVC, the second variable capacitor, and the sensor, the control circuit configured to:
• carry out a first process of:
• determining a parameter-based value based on the measured parameter;
• using the parameter-based value, determining a second variable capacitor configuration and an RF source frequency for reducing a reflected power;
• and
• causing an alteration of the second variable capacitor to the second variable capacitor configuration, and causing an alteration of the RF source to the RF source frequency;
• and
• carry out a second process of:
• upon determining that the alteration of the RF source frequency has caused the RF source frequency to be outside, at a minimum, or at a maximum of a predetermined frequency range, determining a new MVC configuration to cause the RF source frequency, according to the first process, to be altered to be within or closer to the predetermined frequency range, wherein the determination of the new MVC configuration is based on the RF source frequency and the predetermined frequency range;
• and
• causing an alteration of the MVC to the new MVC configuration.

A semiconductor processing tool comprising:

• a plasma chamber configured to deposit a material onto a substrate or etch a material from the substrate;
• and
• an impedance matching network operably coupled to the plasma chamber, the matching network comprising:
• an RF input configured to operably couple to an RF source;
• an RF output configured to operably couple to the plasma chamber;
• a mechanically variable capacitor (MVC);
• an inductor coupled in series or parallel to the MVC;
• a second variable capacitor separate and distinct from the MVC;
• a sensor configured to measure a parameter related to the plasma chamber;
• and
• a control circuit operably coupled to the MVC, the second variable capacitor, and the sensor, the control circuit configured to:
• carry out a first process of:
• determining a parameter-based value based on the measured parameter;
• using the parameter-based value, determining a second variable capacitor configuration and an RF source frequency for reducing a reflected power;
• and
• causing an alteration of the second variable capacitor to the second variable capacitor configuration, and causing an alteration of the RF source to the RF source frequency;
• and
• carry out a second process of:
• upon determining that the alteration of the RF source frequency has caused the RF source frequency to be outside, at a minimum, or at a maximum of a predetermined frequency range, determining a new MVC configuration to cause the RF source frequency, according to the first process, to be altered to be within or closer to the predetermined frequency range, wherein the determination of the new MVC configuration is based on the RF source frequency and the predetermined frequency range;
• and
• causing an alteration of the MVC to the new MVC configuration.

A method of manufacturing a semiconductor, the method comprising:

• placing a substrate in a plasma chamber configured to deposit a material layer onto the substrate or etch a material layer from the substrate;
• coupling a matching network between an RF source and a plasma chamber, the matching network comprising:
• an RF input configured to operably couple to the RF source;
• an RF output configured to operably couple to the plasma chamber;
• a mechanically variable capacitor (MVC);
• an inductor coupled in series or parallel to the MVC;
• and
• a second variable capacitor separate and distinct from the MVC;
• measuring a parameter related to the plasma chamber;
• carrying out a first process of:
• determining a parameter-based value based on the measured parameter;
• using the parameter-based value, determining a second variable capacitor configuration and an RF source frequency for reducing a reflected power;
• and
• causing an alteration of the second variable capacitor to the second variable capacitor configuration, and causing an alteration of the RF source to the RF source frequency;
• and
• carrying out a second process of:
• upon determining that the alteration of the RF source frequency has caused the RF source frequency to be outside, at a minimum, or at a maximum of a predetermined frequency range, determining a new MVC configuration to cause the RF source frequency, according to the first process, to be altered to be within or closer to the predetermined frequency range, wherein the determination of the new MVC configuration is based on the RF source frequency and the predetermined frequency range;
• and
• causing an alteration of the MVC to the new MVC configuration.