Etching process flow

1. Base cleaning

Ultrasonic cleaning, acid/alkali solution treatment (such as RCA cleaning), plasma cleaning and other methods are used to remove surface pollutants (oil, particles, oxide layer).

2. Photoresist Coating

Rotate the coating to form a uniform photoresist layer, pre bake to remove solvents, and enhance adhesion.

3. Exposure and development

Exposure: Using a mask to irradiate with ultraviolet light, deep ultraviolet light, or extreme ultraviolet light to induce a photochemical reaction in the photoresist.

Development: Dissolve the exposed area (positive gel) or unexposed area (negative gel) with a developing solution to expose the area to be etched.

4. Etching

Wet etching: Immerse the substrate in an etching solution or treat it by spraying.

Dry etching: A reactive gas (such as Cl ₂, CF ₄) is introduced into a vacuum chamber to excite plasma for etching.

5. Remove photoresist stripping

Wet gelatinization: Use solvents such as acetone, N-methylpyrrolidone (NMP), or strong acids/oxidants (such as H ₂ SO ₄+H ₂ O ₂).

Dry gelatinization: Oxygen plasma ashing, efficient and residue free.

6. Post processing&Inspection

Cleaning: Remove etching by-products and residual reagents.

Detection: Analyze its morphology, measure its size, and conduct electrical testing through microscope scanning.