Fotorezisti

Fotorezisti are light-sensitive materials used in photolithography, a process crucial for manufacturing integrated circuits and other microelectronic devices. These materials change their chemical properties when exposed to light of a specific wavelength. There are two main types: positive fotorezisti and negative fotorezisti.

In positive fotorezisti, the exposed areas become soluble in a developer solution. When a pattern of light is projected onto the fotorezist-coated substrate, the illuminated regions are removed during development, leaving the unexposed areas intact. This creates a pattern that is a direct replica of the light mask.

Negative fotorezisti, conversely, become less soluble or even insoluble in the developer after light exposure. The unexposed areas are washed away, leaving the exposed regions behind. This results in a pattern that is the inverse of the light mask.

Fotorezisti are applied as thin films, typically through spin-coating. The process of creating a circuit pattern involves coating a substrate with fotorezist, exposing it to UV light through a photomask, and then developing it to transfer the pattern onto the substrate. This pattern can then be etched or used for other fabrication steps. The selection of the appropriate fotorezist depends on factors such as the desired resolution, wavelength of light used, and the subsequent processing steps.