The following is the specific process of using a radio frequency magnetron sputtering coating instrument to coat conductive films on scanning electron microscope samples:

1. Preliminary preparation

Selecting suitable target materials: Based on the properties of the desired film, select the corresponding target materials, commonly including gold, platinum, gold palladium alloy, silver, lead, copper, chromium, antimony, etc. Different target materials will affect the performance characteristics of the final formed conductive film.

Preparation of substrate (sample): Ensure that the surface of the sample to be coated is clean and free of contamination, and if necessary, perform pre-treatment operations such as grinding, polishing, or chemical cleaning to ensure good adhesion and coating effect.

2. Vacuum pumping of RF magnetron sputtering coating system

Start the equipment related devices: turn on the circulating water, turn on the main power, then start the "coating chamber mechanical pump" and "sample chamber mechanical pump", and then open the two 35 degree valves to the maximum position. When the thermocouple vacuum gauge shows a pressure less than 10pa, close these two 35 angle valves; Afterwards, open the "Coating Chamber Front Valve" and "Sample Chamber Front Valve", start the molecular pump, and press the green "Run" button. Finally, open the gate valves of the coating chamber and sample chamber to the fully open position (turn counterclockwise to the bottom). Wait for the molecular pump frequency to reach a stable state, such as the coating chamber reaching 400Hz and the sample chamber reaching 450Hz. At this point, check the numerical changes in the vacuum display window and continue with the subsequent steps.

Monitor vacuum level: Pay close attention to the increase in vacuum level throughout the entire process until it reaches the predetermined high vacuum level. A high vacuum environment helps reduce the interference of gas impurities on the sputtering process, ensuring the quality and purity of the deposited thin film.

3. Adjust sputtering parameters

Setting parameters such as RF power, working pressure, gas flow rate, and deposition time: The specific settings of these parameters need to be determined based on the experimental purpose and the type of substrate. Reasonable parameter settings are key factors in ensuring film uniformity and adhesion. For example, the energy of ion bombardment on the target material can be controlled by adjusting the RF power; The working pressure and gas flow rate affect the concentration and distribution of plasma; The deposition time determines the thickness of the film.

4. The RF magnetron sputtering coating machine begins the sputtering process

Pre sputtering cleaning of target material surface: After turning on the RF power, pre sputtering is performed for a period of time (such as about 10 minutes) to clean the possible oxides or other pollutants on the surface of the target material, making the subsequently deposited film purer.

Formal deposition of thin film: After pre sputtering is completed, turn on the sample stage control power and press the "start" button to start rotating the sample stage. Simultaneously turn on the target and sample baffle switches, and the sputtering coating officially begins. During the sputtering process, the pressure can be fine tuned as needed to maintain it within the set range, ensuring stable film quality.

5. Post processing (optional)

Perform heat treatment, laser treatment, or chemical modification as needed: If there are special requirements for the deposited film, such as improving crystallization performance, enhancing certain physical properties, etc., corresponding post-treatment processes can be carried out after sputtering is completed. But this is not a necessary step, and it depends on the specific application requirements to determine whether and how to implement it.

6. End operation of RF magnetron sputtering coating instrument

Turn off the equipment: After the coating time reaches the set value, first close the baffle (including the sample stage baffle and the target material baffle), stop the rotation of the sample stage, and press the "stop" button on the sample stage. Then turn the power knob of the instrument control part to the minimum. For the RF power supply, press the red button to turn it off first, and then press the yellow button to turn it off; The DC power supply is directly turned off in red. Next, turn off the Ar gas flow control power, adjust the flow to the displayed value of 0, and operate the "valve control" to the "closed" state. Finally, turn off other related equipment and valves in sequence to complete the entire coating process.

7. Take out the sample

After confirming the air pressure balance, remove: Before turning off all equipment and restoring normal pressure, make sure that the air pressure in the coating chamber and the sample chamber is consistent (both are atmospheric pressure or vacuum), then turn on the lighting in both chambers and carefully remove the sample that has been coated with conductive film.