Wafer Photoresist (Step 2)

Photoresists are light-sensitive polymers applied to wafers to transfer circuit patterns during photolithography. When exposed to ultraviolet (DUV) or extreme ultraviolet (EUV) light through a photomask, photoresists undergo chemical changes that allow selective removal during development. They are critical consumables that directly impact resolution, line-edge roughness, and overall yield in semiconductor fabrication.

Photoresist Types

• Positive Resists: Exposed regions become soluble in developer; widely used for high-resolution patterning.
• Negative Resists: Exposed regions crosslink and remain insoluble; used in MEMS and packaging lithography.
• Chemically Amplified Resists (CAR): Rely on acid-catalyzed reactions; dominant for DUV and EUV lithography.
• EUV-Specific Resists: Engineered for high photon absorption at 13.5 nm; critical for advanced nodes at 7 nm, 5 nm, and below.

Major Equipment & Application Tools

• Spin Coaters: Uniformly apply thin resist films to wafers (1–2 µm thickness typical).
• Bake Tools: Soft bake (pre-exposure), post-exposure bake, and hard bake ovens.
• Track Systems: Integrated resist coat/develop modules aligned with lithography scanners.

Representative Photoresist Suppliers

• JSR Corporation (Japan): Leading global supplier of DUV and EUV resists.
• Tokyo Ohka Kogyo (TOK, Japan): Longtime leader in photoresist chemistry and ancillaries.
• Shin-Etsu Chemical (Japan): Supplier of advanced resists and BARC materials.
• DuPont (U.S.): EUV resists and photoresist formulations for packaging.
• Merck (Germany): Advanced resists, developers, and anti-reflective coatings.

Process Consumables

• Developers: Tetramethylammonium hydroxide (TMAH) aqueous solutions.
• Anti-Reflective Coatings (ARC/BARC): Reduce standing wave effects during exposure.
• Ultrapure Water (UPW): Rinse between resist coat, bake, and develop steps.

Cleanroom & Environment

• Resist coating performed in Class 1 cleanrooms to minimize particle defects.
• Track systems integrated with lithography scanners for fully automated wafer handling.
• Temperature and humidity tightly controlled for resist uniformity and sensitivity.

Advantages & Constraints

• Advantages: High selectivity, precise control of line widths, essential for scaling features to nanometer dimensions.
• Constraints: Line-edge roughness, sensitivity vs resolution trade-offs, environmental and safety concerns with solvents and TMAH toxicity.

Market Outlook

The photoresist market is projected to exceed $6 billion by 2030, with EUV resists representing the fastest-growing segment. Research is underway into novel platforms such as metal-oxide resists and molecular resists to extend scaling beyond 3 nm.

Meta Data

• Meta Title: Photoresists in Semiconductor Manufacturing | Lithography Materials
• Meta Description: Photoresists enable pattern transfer during lithography. Explore positive vs negative resists, EUV resists, major suppliers, consumables, and market outlook.