Calibration assembly for a lithium deposition process, lithium deposition apparatus, and method of determining a lithium deposition rate in a lithium deposition process

A lithium deposition apparatus, comprising:

• a calibration assembly, the calibration assembly comprising:
• a carrier;
• and
• a piezoelectric resonator coupled to the carrier, wherein:
• the calibration assembly is configured for being processed in the lithium deposition process, the lithium deposition process including a passivation,
• the piezoelectric resonator is configured for being electrically connected to a driver for determining a resonant frequency of the piezoelectric resonator,
• the resonant frequency is indicative of a thickness of a lithium film deposited on the piezoelectric resonator in the lithium deposition process, and
• a change of the resonant frequency over time is indicative of the passivation of the lithium film;
• the lithium deposition apparatus further comprising:
• a processing chamber, comprising a lithium evaporation device;
• and a transfer chamber connected to the processing chamber, wherein the lithium deposition apparatus is configured for:
• processing the calibration assembly in the processing chamber,
• transferring the calibration assembly from the processing chamber to the transfer chamber,
• passivating a lithium film deposited on the calibration assembly during processing in the transfer chamber, and
• electrically connecting the piezoelectric resonator to a driver with a connector, the connector being provided in a testing environment.

A method of determining a lithium deposition rate in a lithium deposition process, the method comprising:

• providing a calibration assembly comprising a carrier and a piezoelectric resonator coupled to the carrier;
• processing the calibration assembly as a substrate in a processing chamber of the lithium deposition process, wherein the piezoelectric resonator is disconnected from a driver during processing;
• removing the calibration assembly from the processing chamber;
• electrically connecting the piezoelectric resonator to a driver;
• determining a resonant frequency of the piezoelectric resonator, wherein the resonant frequency is indicative of a thickness of a lithium film deposited on the piezoelectric resonator in the lithium deposition process;
• and
• determining the lithium deposition rate from the thickness of the lithium film.

A method of characterizing a lithium deposition process, the method comprising:

• providing a calibration assembly comprising a carrier and a piezoelectric resonator coupled to the carrier;
• processing the calibration assembly as a substrate in a processing chamber of the lithium deposition process;
• forming a passivation layer on the lithium film deposited on the piezoelectric resonator to form a passivated lithium film;
• removing the calibration assembly from the processing chamber;
• electrically connecting the piezoelectric resonator to a driver;
• determining a first resonant frequency of the piezoelectric resonator, wherein the first resonant frequency is indicative of a thickness of a lithium film deposited on the piezoelectric resonator in the lithium deposition process;
• determining a second resonant frequency, wherein:
• determining the second resonant frequency comprises monitoring a change of the second resonant frequency of the piezoelectric resonator over time, and
• a change of the second resonant frequency over time is indicative of the chemical stability of the passivated lithium film.