Discharge and Modulation System and Method for Microwave-Radio Frequency (RF) Mixed Coupled Plasma

A discharge and modulation system for a microwave-radio frequency (RF) mixed coupled plasma, comprising:

• a gas distribution system, a plurality of power supplies, an ion beam current generation device, a Faraday cup, and a computer;
• wherein the plurality of power supplies are respectively an accelerating grid direct current (DC) regulated power supply, a screen grid DC regulated power supply, an RF power supply, an electron extraction electrode DC regulated power supply, and a solid-state microwave power supply;
• the ion beam current generation device comprises:
• a metal shielding enclosure with an opening at a top, and a first metal microwave shielding shell, a microwave antenna, a microwave static magnetic field, a microwave discharge chamber, an electron extraction grid, a gas distributor, a second metal microwave shielding shell, an RF coil, an RF-enhanced discharge chamber, and an ion extraction grid that are disposed inside the metal shielding enclosure;
• the second metal microwave shielding shell, the microwave antenna, the microwave static magnetic field, the microwave discharge chamber, and the electron extraction grid jointly enclose an Electron Cyclotron Resonance (ECR) region;
• the Faraday cup is disposed in an emission direction of an ion beam current from the ion extraction grid;
• and the RF coil surrounds a periphery of the RF-enhanced discharge chamber;
• the gas distribution system, the accelerating grid DC regulated power supply, the screen grid DC regulated power supply, the RF power supply, the electron extraction electrode DC regulated power supply, the solid-state microwave power supply, and the Faraday cup are all connected to the computer;
• the gas distribution system is connected to the gas distributor;
• and the solid-state microwave power supply is connected to the microwave antenna, the electron extraction electrode DC regulated power supply is connected to the electron extraction grid, the RF power supply is connected to the RF coil, and both the accelerating grid DC regulated power supply and the screen grid DC regulated power supply are connected to the ion extraction grid;
• the computer is configured to obtain an etching requirement and determine a ratio of a process gas based on the etching requirement;
• the gas distribution system is configured to store the process gas and deliver the process gas to the gas distributor based on the ratio;
• the gas distributor is configured to deliver a portion of the process gas to the ECR region and deliver another portion of the process gas to the RF-enhanced discharge chamber;
• the solid-state microwave power supply is configured to adjust a power of the solid-state microwave power supply under control of the computer, so as to adjust a power of the microwave antenna, such that the process gas in the ECR region discharges to form an initial plasma;
• the electron extraction electrode DC regulated power supply is configured to adjust a voltage of the electron extraction electrode DC regulated power supply under the control of the computer, so as to adjust a voltage of the electron extraction grid, and extract an electron from the initial plasma into the RF-enhanced discharge chamber;
• the RF power supply is configured to adjust a power of the RF power supply under the control of the computer to generate an RF voltage, and apply the RF voltage to the RF coil, such that the electron further collides with the process gas in the RF-enhanced discharge chamber to form a high-density plasma, wherein the high-density plasma is a plasma whose density is higher than a density of the initial plasma;
• the screen grid DC regulated power supply and the accelerating grid DC regulated power supply are configured to adjust a voltage of the ion extraction grid to a voltage meeting a voltage requirement under the control of the computer, such that an ion within the high-density plasma is acceleratively extracted to form an ion beam current;
• the Faraday cup is configured to measure a density of the ion beam current;
• and
• the computer is further configured to:
• determine whether the density of the ion beam current meets a stability requirement, wherein the stability requirement is that a density of an ion beam current output by the ion extraction grid meets a density requirement within a set period of time;
• and
• when the density of the ion beam current meets the stability requirement, determine the ion beam current output by the ion extraction grid as a target ion beam current for etching;
• or
• when the density of the ion beam current does not meet the stability requirement, control each of the plurality of power supplies to perform voltage or power adjustment until the density of the ion beam current meets the stability requirement, and obtain a target ion beam current.