How can the microelectronics industry improve its environmental footprint?

Enhancing operational efficiency with water-based cleaning products that make zero concessions on performance 

In 2021, global semiconductor unit sales reached a record 1.15 trillion-unit shipments, and in 2022, global semiconductor industry sales topped €573 billion. The sector’s environmental impact is significant. While decarbonizing its energy supply is an obvious step toward reducing its impact on the planet, it’s not enough. Around the globe, microelectronics operations managers and sustainability staff are looking for sustainable solutions to every aspect of their operations. 

One often overlooked potential for implementing greener operations lies in changing your cleaning processes. Wet chemistry applications in microelectronics are a $3B industry; or, in other words, an industry using 500 million liters of chemicals. As cleaning is a key process in the microelectronics industry, changing how you do it may feel scary. A seamless integration with existing processes and compatibility with existing equipment are key. So is ensuring that effectiveness and reliability are not negatively affected. So far, solutions have either delivered on green credentials or on effectiveness.

In this article, we explain how the use of our intelligent fluids will move the microelectronics industry toward greener operations and make the use of toxic chemicals obsolete.

 

Cleaning of microelectronics requires the highest precision

In recent years, the trend of miniaturization has led to ever smaller chips. Microchips consist of transistors, each only a few dozen nanometers in size. For comparison, a human red blood cell is 7,000 nanometers in diameter. 

Any degree of surface contamination on microelectronic components can have a negative impact on the performance of the final electronic product, and even lead to defects. To maintain their performance and reliability, numerous cleaning steps are necessary during production. The production process of a chip that is installed in a computer, for example, involves a long chain of 500 processing steps. Each of them takes place in the nanometer range. Between the various production steps, resist needs to be removed again and again. 

As microchips get smaller, the margin for error in the form of surface impurities and material damage becomes incredibly small. The continuous cleaning of these extremely small components poses a major technical challenge.

Intelligent fluids offer decisive advantages over chemical products

Intelligent Fluids uses an entirely new science-based technology that physically takes off any organic contaminant, whereas traditional cleaning products use toxic and aggressive chemicals to dissolve contaminants. Two fundamentally different approaches that solve the same problem, but with different results.

Increased yield and reduced waste

In contrast to a classic solvent, impurities are not dissolved in the chemical used, but are physically removed

If, for example, resist is to be removed, our intelligent fluids will lift off the layer from the substrate. The advantage over dissolution is that the intelligent fluids are not contaminated in the process and can be used much longer with increased throughput. Our clients have observed bath-lifetime increases of 100% and over. 

The filtering of the contamination enables the detached resist to be incinerated separately. This results in less waste in the drain system, increasing the service life of the cleaning agent and protecting the environment.

Reduced process time

Our intelligent fluids can be tuned precisely to customers’ needs. For example, the etching rate can be adjusted exactly as required by the customer. The physical principle of operation enables such thorough cleaning that some process steps can be skipped, resulting in shorter process times and reducing the cost of ownership.

 

[Caption] Before the stripping process

[Caption] After the stripping process using intelligent fluids

In this example of a positive photoresist removal, the use of intelligent fluids reduces process steps by half and also eliminates the need for hot and cold solvent processes that damage the sidewalls.

Reduced total cost of ownership

Using our intelligent fluids reduces total cost of ownership by saving costs on equipment maintenance, operations, shipping, handling and storage, and environmental, health and safety measures. Furthermore, lower operating temperatures of just 20-50°C reduce energy costs by up to 60% and mitigate fire hazards.

Contrasting traditional cleaning processes with the use of our intelligent fluids, we have observed:

    • Cleaning agent and water cost reduction of up to 67%
    • Equipment maintenance cost reduction of up to 72%
    • Operating cost reduction of up to 40%
    • Cleaning agent shipping, handling and storage cost reduction of up to 41%
    • Environment, health and safety cost reduction of up to 79%
    • Wafer scrap cost reduction of up to 76%
    • Total cost of ownership reduction of up to 67%

Enhanced operational efficiency

The use of aggressive chemical solvents is effective, but often damages the material being cleaned. Intelligent fluids are at least as effective as existing solutions and the physical lift off technology means that materials are not damaged.

[Caption] Removal of positive PR with NMP leaves a corrugated surface as well as irregular sidewall diameter.

[Caption] Removal of positive PR with intelligent fluids produces a smooth surface as well as a smooth sidewall.

When holes are being drilled through etching, sidewall cleaning is extremely important. Here we see how the use of NMP leads to corrugated walls, while the use of intelligent fluids  leads to straight and smooth edges. As metal will need to be filled into these holes, smoother edges are key to ensuring excellent manufacturing outcomes. This leads to higher wafer yields, which directly improves the efficiency of operations.

In the example above the stripping time is below two minutes, at an operating temperature of 50°C. In contrast, the process with NMP requires over 20 minutes at a temperature of 90°C. Maintaining a bath at a temperature of  90°C contributes significantly to the energy requirement of the process.

Finally, using intelligent fluids allows the completion of the cleaning process in just two steps, as opposed to 3 steps with NMP, as it eliminates the need for rinsing with Iso-Propyl Alcohol (IPA rinse) before the Deionized water (DI) rinse. This reduces material usage as well as the process time.

We have observed this superior performance across other processes. The outcomes with negative PR stripping, for instance, are similarly beneficial, with the NMP process requiring 60 minutes at 60°C, while using intelligent fluids leads to a ten-minute process at just 40°C. 

Compatibility with existing materials and equipment, and compliance with industry standards and environmental regulations 

Our drop-in products work with existing equipment and need less maintenance. Intelligent fluids are water-based products with biodegradable ingredients. As such they are safe for the environment and human health. They contain no toxic ingredients, are non-flammable, ph-neutral, thermodynamically stable and dermatologically tested. Because no toxic chemical agents are used, our intelligent fluids comply with all health, safety and environmental regulations in the microelectronics industry.

From research to industry application – Materials for Quantum Computing project (MATQu)

Quantum computing places the highest demands on precision. While we have several ready-to-use products on the market, our team continues to be at the forefront of research and development by contributing to the European Materials for Quantum Computing (MATQu) project. Together with major research and technology organizations, we are working on the industrial market introduction of novel materials and devices to create a complete value chain for Josephson junction technology in Europe.

The microelectronics industry is taking strides toward greener operations

Our intelligent fluids have been tried and tested by several microelectronics companies. Awareness is growing rapidly and major players are convinced by the benefits of a green cleaning solution that makes no concessions to performance.

We are currently growing our production facilities in Europe and are setting up production capacity in India to serve the Asian market.

Are you interested in reliable and effective cleaning that will significantly reduce your total cost of ownership and make your manufacturing processes more sustainable? Get in touch with us and follow us on LinkedIn!