Fabrication of Bi₂Te₃ and Sb₂Te₃ Thermoelectric Thin Films using Radio Frequency Magnetron Sputtering Technique

Our research focuses on fabricating high quality thin films, water electric generators, to recover waste heat and dirt heat into electricity. Various thin film deposition technique have been researched and developed, including radio frequency magnet transporting that is able to produce high density, robust thin films with better adhesion and high uniformity. This method does not require melting and evaporation of the target materials, enabling most of materials to be deposited regardless of the melting temperature, making it superior than other physical vapor deposition technologies.

To begin, remove the aluminum shield from the gun and place the target material at the center of the cover. Securely tighten the cover on the magnetron holder and reattach the aluminum shield. Wrap the chamber body, guns, and sample holder with aluminum foil.

Using a multimeter, check for a sort circuit between the chamber bodies, the chamber body and the gun, and the chamber body and the target. Then shut the door and start the vacuuming process in the chamber for 15 to 30 minutes. At the start of the vacuuming, firmly press the door in the body together to ensure a tight seal.

Monitor the pressure gauge to confirm a decrease in pressure. Now, activate the cooler system and set it to 15 degrees Celsius. Turn on the pump and refrigeration buttons, and open the valve connected to the sputtering instrument.

Now adjust the argon gas flow to four standard cubic centimeters per minute and activate the gas toggle switch. Set the rotation speed to 10 RPM and turn on the rotation toggle switch. Press the power button to activate the automatic matching network controller and the radio frequency power supply.

On the automatic matching network controller, use the min/max button, adjust the load and tune to 50%each. Then, switch the mode from manual to auto. On the radio frequency power supply, set the radio frequency power to 50 watts and press the start button.

Set the timer for 15 minutes. Then turn off the RF power and rotation. Set the argonne flow to zero and turn off the toggle switch.

After that, switch off the vacuum. Ensure to turn off the turbomolecular pump before venting the chamber to prevent damage. Next, open the chamber and load the prepared substrates at the outer corner of the rotating sample holder for optimal deposition.

Close the chamber door and vacuum for a minimum of six hours. Activate the cooler system as shown earlier, and open the valve linked to the sputtering instrument. Set the rotation speed, argon flow, automatic matching network controller, and radio frequency as demonstrated earlier.

Press the start button. Then, inspect the chamber for the presence of plasma. Incrementally increase the RF power by five watts every 10 seconds until it reaches 75 watts.

Set the timer for 60 minutes. Afterward, turn off the radio frequency power and the rotation system. Also, shut down the automatic matching network controller and the radio frequency power supply.

Adjust the argon gas flow to zero and turn off the gas toggle switch. Then, switch off the vacuum and ventilate the chamber to open it. Using tweezers, remove all samples from the chamber and place them in a clean petri dish.

Clean the chamber and vacuum it for 10 to 15 minutes to maintain a vacuum condition free from impurities.