polymerresist

A polymer resist is a light-sensitive material used in photolithography. It is a thin film of organic polymer that changes its solubility in a developer solution when exposed to light. This change in solubility allows for the selective removal of certain areas of the resist, creating a pattern on the underlying substrate. Polymer resists are crucial in the fabrication of microelectronic devices, integrated circuits, and micro-electro-mechanical systems (MEMS).

There are two main types of polymer resists: positive resists and negative resists. In a positive resist, the areas exposed to light become more soluble in the developer and are removed. This means the pattern created in the resist is a direct copy of the light pattern. In contrast, a negative resist becomes less soluble or even insoluble after light exposure. The unexposed areas are then removed by the developer, leaving a pattern that is the inverse of the light pattern.

The selection of a polymer resist depends on various factors, including the wavelength of light used for exposure, the desired resolution, the type of substrate, and the processing steps involved. Common resist materials include polymethyl methacrylate (PMMA) for electron-beam lithography and novolak resins for deep ultraviolet (DUV) lithography. The sensitivity, contrast, and adhesion properties of the resist are critical for achieving high-fidelity pattern transfer. After exposure and development, the patterned resist acts as a mask for subsequent processing steps such as etching or material deposition.