fotomaskien

A fotomaskien, often translated as photomask or reticle, is a critical component in photolithography, a process used in the manufacturing of semiconductor devices like integrated circuits. It is essentially a stencil that contains the pattern of a single layer of the circuit. This pattern is typically created by using an electron beam or laser to etch away specific areas of a light-blocking material, such as chromium, deposited on a transparent substrate, usually quartz or fused silica.

During photolithography, a light source, often ultraviolet, shines through the photomask. The transparent areas of the mask allow light to pass through, exposing a photosensitive material called photoresist coated on a silicon wafer. The opaque areas block the light, leaving the photoresist unexposed in those regions. After exposure, the photoresist is developed, removing either the exposed or unexposed portions depending on whether it is positive or negative photoresist. This leaves a patterned layer of photoresist on the wafer, which then serves as a mask for subsequent etching or deposition processes to transfer the circuit pattern to the underlying wafer material. The precision and accuracy of the photomask directly determine the resolution and complexity of the microelectronic circuits that can be fabricated.