Choosing the Right Litho System: A Buyer’s Guide for Businesses

Litho system troubleshooting requires a distinct approach depending on whether you are working with industrial semiconductor photolithography or commercial offset printing. In semiconductor lithography, issues revolve around micro-scale defect control, chemical adhesion, and exposure precision. In offset printing, problems stem from the mechanical interaction between water, oil-based ink, plates, and rollers. 🔬 1. Semiconductor Photolithography Systems

In microfabrication and semiconductor manufacturing, common defects directly impact chip yield and wafer quality.

Resist Scumming: Unwanted thin residual photoresist remaining in developed areas.

Quick Fix: Increase the development time, optimize the post-exposure bake (PEB) temperature, or apply a short plasma ash step to clear the residue.

Resist Peeling / Poor Adhesion: The photoresist layer lifts or detaches from the substrate during wet etching or development.

Quick Fix: Dehydrate the substrate completely with a high-temperature bake and ensure the uniform application of an adhesion promoter like HMDS before spin-coating.

Blisters or Bubbles: Thermally activated nitrogen gas (N₂) or solvent vapors form bubbles in the resist film during high-temperature steps.

Quick Fix: Introduce a longer holding delay between the UV exposure phase and the post-exposure bake to allow the generated gas to diffuse out naturally.

Substrate Detection Errors: The optical system cannot find or track the surface of the wafer.

Quick Fix: Clean the substrate to remove dark contaminants, check alignment marks, or temporarily reload the substrate to alter its positioning. 📰 2. Commercial Offset Printing Litho Systems

For production printing presses, maintaining a strict balance between chemical properties and mechanical alignments is key. Printing Problems on Press, and How to Avoid Them