Reducing Nodules on Sputtering Targets
Sputtering targets are used by major equipment manufacturers for high volume production of film for metals, dielectrics, transparent conductors, and AR coatings. Materion has been a leading manufacturer of sputtering targets for decades with experience producing targets to support many markets including: semiconductor, data storage, wireless, optical, hybrid/micro electronics and performance films. We offer a solution to the key problem in nodule formation: reducing particulate contamination in the sputtering targets.
One of the challenges with sputtering targets is that they can “grow” nodules as the deposition run proceeds which can ultimately be detrimental to the customer’s product quality. These nodules tend to form on the surface of sputtering targets near the racetrack region (redeposition zone) and may take the shape of a hillock, cone or pyramid. In an extreme case, nodules can cover in excess of 30& of the target surface area. The nodules pose concerns because they can change the sputtering rate, change the angular distribution of sputtered atoms, cause arcing, process drift and destabilization and eventually result in defects in the sputtered film. These nodule problems can cause undesired downtime due to the need for frequent cleaning of target surfaces.
It is thought that the formation of nodules on sputtering targets can be influenced by a number of factors including:
• the cleanliness of the process chamber
• arc handling ability of magnetron power source
• the temperature of target surface during sputtering
• the stability of the process
• particulate contamination in the sputtering targets
• the relative sputtered surface area / redeposition area
Materion can partner with our customers to create enhanced target designs that complement sputtering source designs capable of reducing the relative surface area of redeposited zones where nodules typically form. Through our expertise and superior manufacturing methods, we are able to reduce the contamination that leads to nodule growth and poor performance. Because of our broad manufacturing process capabilities, Materion can manufacture targets of virtually any material or configuration to the exacting specification of all major equipment OEMs.