The Difference Between Positive & Negative Photoresist
Photoresist is a material that semiconductor suppliers are constantly working with. This light-sensitive material is divided into two types: negative and positive, which react in very different ways when exposed to UV light . It is therefore essential to understand each reaction in order to produce the best results in the semiconductor manufacturing industry. Positive Photoresist : UV light is used to expose the resist where the fundamental material is to be detached. Contact with UV light changes the chemical structure of these resists, making them more soluble in the developer. The developer solution then washes away the exposed resist, separating the windows from the base material. The mask thus covers an accurate copy of the shape that will be left on the wafer as a stencil for further processing. Negative Photoresist : A negative photoresist works in the opposite direction. When the negative resist is exposed to UV light, it polymerises and becomes more difficult to dissol