Kuivsöövitustehnika

Kuivsöövitustehnika, also known as dry etching, is a microfabrication process used to remove material from a solid surface in a directional manner. It is commonly employed in the semiconductor industry to pattern thin films. Unlike wet etching, which uses liquid chemicals, dry etching utilizes a plasma or a stream of energetic ions to etch the substrate. This method offers greater control over the etching process, allowing for anisotropic etching, where material is removed primarily in a vertical direction, leading to well-defined structures with steep sidewalls.

The primary mechanism in dry etching involves reactive ions or neutral species generated in a plasma. These species chemically react with the surface of the substrate, forming volatile byproducts that are then pumped away. Alternatively, physical sputtering can occur, where energetic ions bombard the surface and dislodge atoms directly. Often, a combination of chemical and physical processes, known as reactive ion etching (RIE), is used to achieve optimal etching rates and selectivities.

Key advantages of dry etching include its precision, controllability, and ability to create high-aspect-ratio structures. It is essential for fabricating integrated circuits, where intricate patterns with sub-micron features are required. Different types of dry etching exist, such as plasma etching, ion beam etching, and chemically assisted dry etching, each tailored for specific applications and materials. The choice of etching gas, pressure, power, and substrate temperature are critical parameters that influence the etching profile and selectivity.