A sputtering target is a material used to create a thin film in a process known as sputter deposition or thin film deposition. Spray and coat another material called a substrate. Sputter deposition is commonly involved in the manufacture of semiconductors and computer chips.
As a result, most of the sputtering target materials are metallic elements or alloys, thin coatings for various tools. Depending on the thin film type, sputtering targets can vary significantly in size and shape.
The smallest targets can be less than 1 inch in diameter, while the most prominent rectangular targets are over 3 feet long. Some sprayers require a larger spray target, and in these cases, manufacturers create segmented targets connected by specific seals. As a result, the designs of sputtering systems, the machines that perform the thin film deposition process, have become much more varied and specific.
Consequently, the variety of lens shapes and structures has begun to expand. For example, the shape of a sputtering target is usually rectangular or circular, but many target suppliers can create other unique shapes upon request. In addition, specific sputtering systems require a rotating target to provide a more precise and uniform film.
Shaped like long cylinders, these targets offer additional benefits, including faster deposition rates, minor heat damage, and greater surface area, resulting in better overall usability.
The effectiveness of sputtering target materials depends on several factors, including their composition and the type of ions used to break them down. Thin films that require pure metals as the target material generally have higher structural integrity when the target is as pure as possible. The ions used to bombard the sputtering target are critical to producing a decent quality thin film.
Generally, argon is the main gas chosen to ionize and start the spraying process. However, for targets with lighter or heavier molecules, another noble gas such as neon for lighter molecules or krypton for heavier molecules is more effective.
In addition, the atomic weight of the gas ions must be similar to that of the sputtering target molecules to optimize energy transfer and momentum and thus optimize thin film uniformity.