Ion Beam Etching: Precise Processing of Complex Surface Structures

Ion Beam Etching (IBE), also referred to as Ion Beam Milling (IBM), is a highly precise method for surface processing. A broad beam of positively charged ions (typically argon ions) is accelerated onto a substrate. Thereby, the ions transfer their kinetic energy to the surface atoms, causing them to be ejected and thus removing the material. To achieve a uniform and accurate etching result, the substrate is rotated during the process, while the ion beam has a larger diameter than the substrate.

Advantages of Ion Beam Etching:

1. High precision - by etching under a defined angle of incidence and adjustable ion energy, even complex structures can be created with high accuracy.
2. Low substrate temperature, which minimizes heat-induced deformation or damage to the material.
3. High versatility: Ion beam etching is suitable for a wide range of materials, including metals, semiconductors, polymers, and ceramics.
4. Surface cleanliness: oxide layers or other contaminations can be removed from the surface.

Special forms of ion beam etching are Reactive Ion Beam Etching (RIBE) and Chemically Assisted Ion Beam Etching (CAIBE), where reactive gases are used in addition to inert gas, e.g., to increase selectivity, to influence trench angles or to enhance etch rates.