What is the meaning of photolithography?

Photolithography: An Overview

Photolithography, also known as optical lithography or UV lithography, is a process used in microfabrication to pattern parts of a thin film or the bulk of a substrate. It uses light to transfer a geometric pattern from a photomask to a light-sensitive chemical photoresist on the substrate. A series of chemical treatments then either etches the exposure pattern into the material or enables deposition of a new material in the desired pattern upon the material underneath the photoresist.

Key Steps in Photolithography

• Preparation of the substrate.
• Application of the photoresist layer.
• Pre-exposure bake to remove solvent from the photoresist.
• Alignment of the photomask to the substrate.
• Exposure of the photoresist to light through the photomask.
• Post-exposure bake to further develop the photoresist image.
• Development of the photoresist to remove the unexposed or exposed areas.
• Etching to remove material from the substrate or deposition of new material.
• Removal of the remaining photoresist, revealing the patterned material.

Applications

Photolithography is a critical process in the semiconductor industry, used for the fabrication of integrated circuits (ICs) and microelectromechanical systems (MEMS). It enables the precise patterning necessary for the miniaturization of electronics, playing a vital role in the advancement of technology.