What Is a Photoresist?
A photoresist is a light-sensitive material used in semiconductor manufacturing to create patterns on a wafer. It plays a crucial role in the photolithography process, which defines intricate designs for integrated circuits and MEMS devices.
How Are Photoresists Used?
- Coating: A thin layer of photoresist is applied to a wafer using spin coating.
- Exposure: Light passes through a photomask to transfer a pattern onto the photoresist.
- Development: Exposed or unexposed regions are removed, depending on the type of photoresist.
- Etching/Deposition: The patterned photoresist acts as a stencil for etching or depositing materials.
- Stripping: The remaining photoresist is removed after processing.
Applications
- Integrated Circuits (ICs): Patterns transistors, interconnects, and components in chips.
- MEMS Devices: Creates patterns for sensors and actuators.
- Displays: Enables patterns for LCDs and OLEDs.
- Photonics: Fabricates optical waveguides and photonic circuits.
Advantages
- High Resolution: Enables patterning at nanometer scales.
- Precision: Provides accurate pattern transfer for complex designs.
- Versatility: Works with various wavelengths and processes.