What is photoresist development?

Photoresist development is a process used in photolithography to transfer a pattern onto a substrate. It involves the use of a photosensitive polymer called photoresist, which undergoes a chemical reaction when exposed to light. The photoresist is applied to the substrate and then exposed to a patterned image, typically using a mask or a photomask, that allows light to pass through only in specific areas.

After exposure, the substrate with the photoresist is cleaned and developed using a developer solution. The developer solution removes the unexposed areas of the photoresist, leaving behind a patterned layer that can then be used for subsequent processing steps, such as etching or deposition.

There are two types of photoresist development: positive and negative. In positive photoresist development, the exposed areas of the photoresist become more soluble in the developer solution, leading to their removal during development. In negative photoresist development, the exposed areas of the photoresist become less soluble, leaving behind the unexposed areas.

Photoresist development is a crucial step in many semiconductor manufacturing processes, including the production of microchips and microelectromechanical systems (MEMS). It is also used in the production of printed circuit boards, where it is used to create the copper traces that connect the components on the board.