What is sputter etching?

Definition: The process of removing a thin layer of a sample surface by bombarding it with energetic ions.

What are the factors affecting etch rate?

Viable etch rates in HF vapor depend on many factors including whether the process chamber contains a single or multiple wafers, exposed silicon oxide area, type of silicon oxide, feature sizes and designs, whether there are exposed metals and a target uniformity specification.

What does it mean when etch selectivity is low?

Low selectivity is when two materials etch at relatively similar rates. When there is low selectivity a mask will not provide as much protection for etching the material of interest. This means a thicker mask may have to be used to etch to a required depth.

What is loading effect in etching?

The loading effect is a phenomenon in which the etch rate change depending on Si aperture (unmasked area) ratios. On the surface of Si, the fluorine radicals are consumed and the by-product, SiF4, is increased. Therefore, a larger aperture ratio of Si area has less fluorine radicals, and the etching rate becomes lower.

What is a sputter machine?

A sputtering machine is usually a small, sealed chamber where energetic particles such as electrons bombard a source material that ejects atoms off of the surface. These atoms then bounce off of the chamber walls, coating a sample object inside the chamber.

How does a sputtering machine work?

Sputtering is a plasma based deposition process in which energetic ions are accelerated towards a target. The ions strike the target and atoms are ejected (or sputtered) from the surface. These atoms travel towards the substrate and incorporate into the growing film.

How can I increase my etch rate?

Substrate Temperature Like in cooking, the temperature affects the results. The impact of temperature on most materials is an increase in the etch rate. While it might seem that the selectivity would stay constant with increasing temperature, not all materials increase their etch rate by the same proportionate amount.

What is etch profile?

The etch profile refers to the shape of the cavities that are produced during the etching process. For a dry etching process, it is common that recipes are tuned to produce vertical walls. The Bosch dry etching process typically produces ripples (or scallops) on the walls.

How can plasma etch uniformity be improved?

Temperature Control Process temperature is the single most important parameter in the plasma process. Process temperature has primary control over etch rate and has a secondary effect on etch uniformity. The higher the process temperature, the faster the processing rate becomes.

What is the advantage of sputtering?

An important advantage of sputter deposition is that even materials with very high melting points are easily sputtered while evaporation of these materials in a resistance evaporator or Knudsen cell is problematic or impossible. Sputter deposited films have a composition close to that of the source material.

What are the advantages of sputtering process?

Like other physical vapor deposition techniques, ion beam sputtering provides advantages such as deposition rate, uniformity, composition, thickness control, adhesion, and material properties.

What is a sputtering tool?

A magnetron sputtering source is a tool to deposit thin film that mounts to a vacuum chamber by means of either flanges or feedthroughs and consists of a water cooled cathode/target holder with an embedded magnet array and appropriate grounded shielding.