What Is a Photoresist Stripping Agent?

Introduction

In the ever-evolving world of microelectronics, semiconductor manufacturing, and precision optics, the use of photoresist is crucial in photolithography processes. Equally critical is the removal of that photoresist after the patterning stage. This is where photoresist stripping agents come into play. But what exactly is a photoresist stripping agent? Why does its performance matter so much in advanced industries?

What Is a Photoresist Stripping Agent?

Definition and Core Function

A photoresist stripping agent is a chemical formulation specifically designed to remove photoresist layers from substrates after lithographic processes. Photoresists are light-sensitive materials used to form patterned coatings on semiconductor wafers or printed circuit boards (PCBs). After their job is done—protecting certain areas during etching or implantation—they need to be completely stripped off without damaging the underlying structures.

Stripping agents dissolve or lift off these films effectively, allowing the substrate to be cleaned and reused or progressed to the next manufacturing step.

Why Is Effective Stripping So Important?

Preventing Substrate Damage

One of the biggest challenges in photoresist stripping is preserving the integrity of the substrate. Whether dealing with delicate silicon wafers or complex multilayer PCBs, any residue or chemical aggression can result in costly defects or process failures. A high-quality stripping agent ensures full removal without corrosion or surface roughening.

Enabling Precision Manufacturing

In industries like semiconductors and microelectromechanical systems (MEMS), nanometer-level precision is often required. Even a trace amount of photoresist left on the surface can alter electronic performance or device yield. An optimized stripping agent enables manufacturers to achieve superior process reliability and throughput.

Types of Photoresist Stripping Agents

Solvent-Based Stripping Agents

These rely on organic solvents like N-Methyl-2-pyrrolidone (NMP), Dimethyl sulfoxide (DMSO), or other glycol ethers. While solvent-based agents are effective and widely used, they often come with toxicity concerns, flammability risks, and strict disposal regulations.

Water-Based Stripping Agents

In response to environmental and safety concerns, water-based or semi-aqueous strippers have gained popularity. These agents combine surfactants, chelating agents, and corrosion inhibitors to offer eco-friendly solutions. Yuanan has developed formulations that match solvent-based performance while meeting global sustainability standards.

Plasma Ashing (Non-Chemical Alternative)

While not a chemical agent per se, plasma ashing is a dry technique that uses reactive ions to burn off photoresist. However, it often lacks versatility and is not suitable for temperature-sensitive substrates.

Yuanan’s Advanced Photoresist Stripping Agent Solutions

At Yuanan, we understand that not all photoresists are created equal. As such, our product development focuses on creating tailor-made stripping agents for different resist chemistries and substrate types.

Key Features of Yuanan’s Stripping Formulas

• Non-corrosive to metals such as aluminum, copper, and tungsten

• Fast stripping performance for positive and negative tone resists

• Compatible with various substrates, including silicon, glass, and compound semiconductors

• Environmentally responsible, reducing VOCs and toxic residues

• Low residue for critical cleaning in nanofabrication

Application Areas

• Semiconductor wafer cleaning

• LCD and OLED display manufacturing

• MEMS device fabrication

• Printed circuit board (PCB) cleaning

• Hard disk media and optical lens processing

Challenges in Photoresist Stripping

Varying Resist Formulations

As photoresists become more chemically complex—especially in deep UV or EUV lithography—the choice of stripping agent must evolve. Some advanced photoresists are resistant to traditional solvents, necessitating new chemical solutions with stronger, yet safe, removal mechanisms.

Environmental and Regulatory Compliance

Modern manufacturers face increasing pressure to minimize toxic emissions and reduce waste. Solvent-heavy agents are being phased out in favor of greener alternatives. Yuanan addresses this with fully compliant products that meet RoHS, REACH, and local wastewater discharge regulations.

Selecting the Right Photoresist Stripping Agent

Choosing the right stripping agent depends on several technical factors:

• Type of photoresist (positive vs. negative tone)

• Substrate material and its sensitivity to corrosion

• Cleaning method (spray, soak, or ultrasonic)

• Required throughput and cycle time

• Waste treatment considerations

Yuanan provides full technical support and customized solutions to help clients optimize their cleaning processes for maximum yield and reliability.

Conclusion

The photoresist stripping agent is not merely a supporting material—it's a critical enabler in precision manufacturing. Without efficient and safe resist removal, the entire production line could face contamination, yield loss, or equipment damage.

Yuanan’s cutting-edge stripping solutions are designed with performance, safety, and sustainability in mind. With ongoing R&D and a deep understanding of microfabrication needs, we continue to empower industries with reliable, clean, and eco-friendly resist removal technologies.

Whether you are a chipmaker, a display panel manufacturer, or a PCB fabricator, trust Yuanan to deliver excellence in every drop of chemistry.