Increase film adhesion
What is the best way to increase the adhesion of a film?
1. Clean the substrate The surface condition of the substrate greatly influences adhesion. Figure (1) illustrates that if the surface is not cleaned, the film cannot directly contact the substrate and adhesion deteriorates, which significantly reduces the coating's success rate. Ultrasonic cleaning is the best cleaning method, according to our experience.
2. It is beneficial when depositing a film to raise the temperature of the substrate, as this promotes mutual diffusion between the film and substrate, speeds up the chemical reaction, promotes diffusion adhesion, and promotes chemical bond adhesion, which improves adhesion.
3. Forming a transition layer between a film and a substrate can improve the adhesion of the film. It is difficult to adhere the gold film to the glass, for example. To improve adhesion, you can coat the glass with a thin layer of chromium or nickel-chromium. The intermediate transition layer solves the problem of adhesion of the gold film on the glass substrate.
4. The sputtering method has better adhesion performance than vapor deposition when the film and substrate materials are chosen appropriately. Due to the high energy of the sputtered particles, they can eliminate the gas adsorbed on the surface, increase the surface activity, and aid in the diffusion of the film atoms into the substrate, resulting in an improved adhesion.