TechXperience Summit

In current times with shortages of semiconductors, ramp-up of production capacities becomes globally more important than in former times. AP&S implemented an in-house facility and strategy to significantly reduce leaching times of new installed wet process equipment and thus speed-up the availability for production. Efficient rinsing of every equipment by ultra-high-purity water ensures a reliable cleanliness and quality of the equipments before shipment. Quality monitoring before delivery is done by optical laser counters and different analytics.
By having implemented and continuously optimized the tool purge procedure, a pre-qualification of wet process equipment prior to delivery is possible which also allows a reduced time to production after tool installation in customer fabs.
Benefits of this strategy for our customers will be part of the presentation.

The trend of wet cleaning processes is pointing towards enhanced performance and high throughput by increasing the automation and productivity of batch tools. The NexAStep, the next generation of wet processing, was developed to meet the demands and goals of the rapidly evolving semiconductor industry.

The NexAStep combines automated and modular hardware with a cutting-edge software. A particular highlight is the robot cell with its connection to the OHT, several storage locations, wafer handling, LMC buffer station and other additional outstanding features. Furthermore, the NexAStep exhibits an outstanding throughput, e.g., by reducing process times by applying higher process temperatures, new features for hydrodynamics or higher flow rates for reduced rinsing times.

The production capabilities and performance are demonstrated by analyzing different sequences of the hot Phos, SPM, HF, RCA clean and Marangoni drying processes. Measurements of various performance parameters such as particles, etch rates as well as cleaning efficiency, were among the methods used to examine the accomplishments even of strict specification requirements.

Legacy fabs are semiconductor factories that produce chips using older process nodes and technologies. They were often built in the 1980s or 1990s and utilize less advanced manufacturing processes compared to factories that produce the latest generations of semiconductors.

While modern fabs running fully automated to process 300 mm wafers and focus top notch technologies such as 7 nm, 5 nm or smaller - legacy factories typically operate in manual fashion with larger feature sizes of 65 nm, 90 nm, or even 250 nm and on wafer sizes of 200 mm or smaller.

In recent decades, semiconductor manufacturing has significantly shifted from the USA and Europe to Asia, particularly to China, Taiwan and South Korea.

This trend is currently reversing to some extent, driven by geopolitical influences and the local-for-focal tendency. For the legacy fabs considered here, these changing conditions present an opportunity for a 'revival or second life'. A key requirement for this is the increase in efficiency to maintain the competitiveness of the fabs.

One of the biggest levers to achieve this is modernization through material handling automation...

At Fraunhofer ISIT, we have developed a novel technique called PowderMEMS. This process involves agglomerating loose particles filled in etched cavities into rigid 3D structures using atomic layer deposition (ALD). During the filling process, silicon wafers with etched cavities are filled with powder materials using a semi-automatic powder-filling tool. The excess material from the surface is then removed using a squeegee. However, residual particles remain on the wafer surface and at the edges on the backside, which can contaminate cleanroom equipment if transferred.

We utilize the AP&S SpinScrubber to prevent such contamination by removal of the residual particles from the wafer surface. This cleaning process employs soft brushes and high-pressure cleaning to effectively remove residual particles, ensuring that the wafers are clean and suitable for further processing without compromising the cleanliness of the tools.

In addition to cleaning, the high-pressure cleaning function also serves a characterization role. It helps determine if the agglomeration has reached the bottom of the cavities. By using high-pressure cleaning to remove the agglomerate structures and then performing XeF2 etching, we can verify the completeness of the ALD coating. If the ALD layer has coated the bottom of the cavity, the silicon will resist etching by XeF2 gas. Conversely, the silicon will be etched if the ALD does not reach the bottom. We perform image analysis using AI to evaluate which cavities were fully coated and which were not, helping us optimize the precursor amount needed to achieve complete coating.

Piezoelectric micro-electromechanical systems (piezo-MEMS) are increasingly complementing and substituting electrostatic MEMS. Due to significantly improved power densities as well as increased design freedom, new applications in the field of high-force actuators such as printheads or microspeakers have become possible. As of now, however, the full impact of piezo-MEMS has been held back by the commercially available thin-film piezoelectrics. Compounds like lead-zirconate-titanate (PZT), next to their toxicity, pose a formidable integration challenge, whereas easier to integrate compounds such as AlN do not provide sufficient force.

Therefore, X-FAB and Fraunhofer ISIT are working on implementing AlScN as the next generation of piezoelectric thin films - which combine high power output with a significantly improved integrability. Progressively increasing scandium (Sc) contents have allowed to reach higher and higher forces over the last years, yet a lack of volatile Sc reaction products is hindering the implementation of selective dry etching procedures for ScN concentrations ≥ 30%. Wet etching in turn allows batch processing with high selectivity against e.g. electrode layers for arbitrarily high Sc concentrations.

This contribution will give an overview of the capabilities that wet etching offers in the context of selective patterning of AlScN films with up to 2 µm thickness and ScN contents up to 40% - starting from lab-scale experiments to production suitable high throughput equipment from AP&S.

Effective exhaust pressure control is critical for maintaining wafer quality in semiconductor wet applications, where hazardous gases are generated during processing. Traditional methods, such as butterfly valves, face challenges in delivering precise and dynamic pressure regulation, often leading to issues like chamber cross-talking, pressure fluctuations, and insufficient exhaust flow during tool expansions or chemical buildup.

Innovative exhaust management approaches utilizing advanced technologies now enable precise control of pressure and flow, significantly reducing particle contamination on wafers. These solutions offer faster stabilization times, greater accuracy, and improved adaptability to dynamic process demands. Additionally, they ensure compact design, high power density, and robust chemical resistance, providing reliable operation in demanding environments. Comparative analyses demonstrate enhanced performance in pressure control, disturbance response, and process consistency, paving the way for improved efficiency and yield in semiconductor manufacturing processes.

This lecture provides an overview of the production of radiation detectors at the Semiconductor Laboratory of the Max Planck Institute in Garching. The different types of detectors manufactured at the HLL and their applications will be presented. The individual process steps will then be explained, with a particular focus on the challenges involved in processing wafers structured on both sides. In addition, the new wet etching system from AP&S will be presented, which enables one-sided processing of the wafers without damaging the backside. Finally, the chemicals used and the planned processes will be described.

In today's world with its increasing demand in power semiconductor devices for electrification, e-mobility and enabling the flexible use of green energy it has become more and more imminent that it is not only necessary to involve new semiconductor materials (e.g. SiC, GaN) but also apply alternative manufacturing technologies to maintain the flexibility and reliability on the next generation of power semiconductor devices.

Electroless metallization processes from MKS are part of these alternative technologies for power semiconductor device manufacturing and have been established in the industry over past 15 years with their benefit of providing maskless metallization with higher throughput capability at a reduced Cost of Ownership compared to physical metallization techniques. Usually, electroless processes are being used as final finish on Cu or Al-based substrates but there is also the possibility of direct metallization of semiconductor material (e.g. Si, SiC, GaN) using the electroless processes and create a reliable low ohmic contact.

Wet cleaning is a major part of the semiconductor manufacturing process and is becoming a more critical process with continued node scaling in Logic and Memory. Lithography, deposition steps and epitaxial growth of semiconductor layers cannot be successfully operated without proper pre- and post-cleaning steps. Traditional cleaning processes are based on water or other solvents and wet cleaning has been a standard for a very long time. The challenge today is developing wet cleaning processes that fit the needs of the advanced semiconductor processes with structures heading towards the sub-nanometer area. This paper will provide an overview of the cleaning mechanisms for dissolved gases, along with common applications.

Dissolved gases like dissolved ozone / DiO₃, dissolved ammonia / DiNH₃ or dissolved carbon dioxide / DiCO₂, as provided by MKS Instruments, have been used for cleaning purposes for over 20 years. The unique setup in dissolving a gas in ultrapure water allows for strict contamination control of the cleaning liquid, a prerequisite for successful cleaning of a silicon semiconductor wafer or other surfaces like glass and metals.

Main applications for dissolved gases are:

• Surface Cleaning (DiO₃, DiNH₃)
• Oxide Growth (DiO₃)
• Controlled Etch or trimming (DiO₃, DiNH₃)
• Rinsing (DiCO₂, DiNH₃)
• Photoresist stripping (DiO₃)
• Post-CMP and post-grinding cleans (DiO₃)

Ozone is a strong oxidizer and is used as a standard for surface cleaning on Silicon in the sequence DiO₃ + HF; at medium DiO₃ concentrations of 10 - 50 ppm, a silicon oxide layer is formed and subsequently removed to clean the surface from particles, organics and other contaminants. DiO₃ for removal of organics is the main application for dissolved ozone in semiconductor manufacturing.

DiO₃ alone is used to create very thin oxide layers of 0.4 - 1.2 nm on silicon. These SiO₂ layer are widely used in semiconductor manufacturing as protection layer, to shield the semiconductor surface, for conditioning, to create hydrophilic surfaces and as interfacial layer in 2D and 3D device structures.

 The very first application for DiO₃ was in Photoresist (PR) strip. Where 60 - 100 ppm DiO₃ was used in the beginning of the 2000^thdue to recent developments, MKS Instruments offers DiO₃ concentrations up to 200 ppm for effective stripping of PR layers during lithography.

In the medium concentration range, also other DiO₃ applications emerged: post-CMP (Chemical-Mechanical Polishing) or post-grinding at 3 - 30 ppm DiO₃ is a very effective cleaning process after planarization of surfaces.

Next to DiO₃i.e. Dissolved Ammonia / DiNH₃ and Dissolved Carbon Dioxide / DiCO₂ are widely used dissolved gases in semiconductor manufacturing. The main application of both, DiNH₃ and CO₂ is ESD prevention in rinsing processes; ESD is electrostatic discharge that can be observed when small semiconductor structures are rinsed with ultrapure water. Due to the high resistance of UPW, arcing can occur, and structure are destroyed during the rinsing process. DiNH₃ and DiCO₂ in low concentrations will prevent arcing.

Finally, DiO₃ or DiNH₃, at very low concentration, are used for wet specialty etches and trimming processes in semiconductor but also in photomask manufacturing.

In summary, all three gases dissolved in ultrapure water can be used for standard cleaning and rinsing applications but also for specialties like etching and oxidation. Single wafer cleaning applications are a standard but also batch processes are widely used. Dissolved ammonia and dissolved carbon dioxide are essential for cleaning of small structures in semiconductor manufacturing. Dissolved ozone is a powerful green alternative to oxidizers like sulfuric acid or hydrogen peroxide. Traditional applications in oxide growth, photoresist stripping and surface cleaning in advanced nodes will now be extended into new applications on the wafer backside and advanced packaging.

MKS Instruments follows the trend of green initiatives to save resources like energy and water. For DiO₃, a reclaim system was developed to save resources during process brakes and to lower the overall carbon footprint of the process.

MKS has a 25-year-experience in Dissolved Gases business and an install base of around 3.000 systems globally; the product family of the DiO₃ delivery system, the LIQUOZON, has the biggest share. The heart of the DiO₃ system is MKS's powerful ozone gas generator. MKS offers a variable platform for dissolved ozone and ammonia systems with a high level of customization that secures MKS's position as the market leader in cleaning applications with dissolved gases in semiconductor manufacturing.

This paper provides an in-depth analysis of global power consumption, the proportion attributable to electric power, and its projected future development. This discussion is contextualized with the growing waste stream of obsolete electronic equipment, highlighting the partial efficacy of current recycling practices in mitigating environmental toxicity. The paper also explores EU regulations and recommendations promoting circular economy principles as a strategy to reduce electronic waste and suggests innovative approaches for the design of power electronic circuits conducive to a circular economy.

#### Introduction

Global primary energy consumption was approximately 160 TWh in 2022, with electric energy consumption accounting for around 30 TWh. Electric power consumption has exhibited a compound annual growth rate (CAGR) of approximately 3% over the past 120 years, since the early 1900s. Currently, this consumption is segmented into four main sectors: residential, transportation, industrial, and commercial.

#### Future Demand Drivers

Projected demand drivers suggest a significant increase in electric energy consumption, estimated to exceed 12 PWh per year by 2030. Key contributors to this growth include:

- Data centers, artificial intelligence, air conditioning, and household appliances, contributing over 6 PWh per year.

- Growing demands in marine, trucking, aviation, and charging infrastructure, exceeding 2 PWh per year.

- Industrial electrification, digitalization, urbanization, energy storage, and grid expansion, totaling over 3 PWh per year.

- Building electrification and renewables integration, adding another 2 PWh per year.

#### Electronic Waste and Recycling

This anticipated growth in electric energy demand is compounded by the current electronic waste stream, which exceeds 64 million tons per year (UNTAR report: e-waste monitor 2024). The United Nations predicts that this e-waste will remain the world's fastest-growing waste stream, with a significant environmental impact due to incomplete recycling of toxic materials such as mercury and bromine. Alarmingly, the UN forecasts that the recycling rate will decline from 22.3% in 2022 to below 20% by 2030.

#### EU Regulatory Framework

The European Union's Green Deal 2050 has identified electronic waste (exceeding 16 kg per person in 2022) as a critical area for action. The EU explicitly advocates for circular economy initiatives in electronics, as evidenced by the recent "right to repair" legislation.

#### Innovation in semiconductor design

Historically, electronic circuit design, including power electronics, has followed a "throw-away" mentality, focusing on single-application use. Transitioning to a circular economy necessitates redesigning electronic circuits to accommodate multiple applications. Key considerations include:

- Reliability:** Ensuring long-term performance across different applications.

- **Health Monitoring:** Incorporating systems to monitor component health.

- Component Aging:** Understanding and mitigating the effects of aging components.

- **Documentation:** Comprehensive documentation for maintenance and reuse.

- Licensing:** Clear licensing to facilitate component repurposing.

- Software Analysis:** Advanced software tools for analysis and validation.

- **User Education:** Educating users on the benefits and practices of circular economy principles.

#### Conclusion

The transition to a circular economy in power electronics presents both challenges and opportunities. By embracing innovative design approaches and adhering to regulatory frameworks, the industry can significantly reduce its environmental footprint while meeting the growing demand for electric power.

As we confront the escalating global environmental challenges, the significance of sustainability is becoming increasingly critical across all industries. In particular, the semiconductor industry feels this urgency and is striving for more sustainable practices. This presentation will shed light on the innovative strategies that are driving this shift towards sustainability. It will explore how chemical metrology is evolving to support and meet these demands, ensuring greener and more sustainable processes.

We will discuss how measurement strategies can extend the lifetime of chemical baths while ensuring high-yield production and reducing waste. This approach not only improves efficiency but also contributes to sustainability.

We'll also discuss direct metal replenishment, a method for reducing bleed-and-feed volumes in copper and tin plating, optimizing resource use. It ensures continuous metal supply, minimizing anode changes and down-time, enhancing productivity and cost savings, which becomes essential with the continuous growth of Advanced Packaging applications.

The presentation additionally emphasizes non-reagent techniques in chemical metrology and process control. These techniques aim to decrease chemical usage, promoting sustainable practices. They utilize advanced technologies to achieve accurate results without extensive chemical use, reducing environmental impact and costs. In process control, reduced chemical usage leads to safer operations, minimizes risk of accidents, and provides faster, real-time control, improving overall efficiency.

In conclusion, this presentation highlights the need for sustainability in the semiconductor industry through innovative strategies. We explore holistic measurement strategies, direct metal replenishment, and non-reagent techniques that enhance efficiency, reduce environmental impact, and promote safer operations.

The wet etch process of the brasable metal stack (Ti/Ni/Ag) on SiC power MOSFET devices has been implemented as a full wet approach in our Spin Step tool including the resist removal. Metal residues have been observed by SEM inspection on the polyimide surface, the Auger analysis detected the presence of nickel. A more effective cleaning was necessary to remove the nickel, tuning the steps of the recipe good result was observed with the SC1 before the Ti etch.

To tackle the complexities of the European integrated circuit (IC) landscape-including process diversity, raw material availability, stringent environmental targets, and evolving regulations - a systemic approach is essential when designing new surface preparation processes.

Building on the success of collaborative initiatives, including French & European consortia and partnerships with research and technology organizations (RTOs), equipment suppliers and end-users, these efforts have created opportunities for near real-time industrial research and experimental validation in representative environments.

Through these joint developments, process benchmarking, life cycle analysis, and risk assessments, these efforts have demonstrated how advanced surface preparation processes can be optimized to reduce development cycle time, costs and risks for end-users. Furthermore, they have provided valuable insights into key parameters such as health, safety, and environmental (HSE) considerations, energy efficiency, raw material resilience, and waste management supporting the transition to more sustainable and efficient semiconductor manufacturing practices.

Few examples of successful outcomes including the development of TMAH- and NMP-free strippers, catechol/hydroxylamine-free post-etch residue (PER) cleaners, and bioaccumulative free chelators& surfactants for metal etchants will be presented.

Hybrid and vitrified bond grinding tools represent a quantum leap in quality and reliability in semiconductor processing. Meister Abrasives' diamond grinding tools target boule, puck, seed, and wafer grinding. With a best-in-class total topography (Sa, Sz, Bow, Warp, TTV), surface qualities in the one-digit Angstrom range are achieved. The specially developed grinding tools of Meister Abrasives are used for processing a wide range of materials such as silicon carbide (SiC),poly silicon carbide(pSiC), silicon (Si).

Meister Abrasives' innovative grinding wheel technologies allow prime wafer and device manufacturers to shorten wafer preparation steps to the minimum. For example, the ultra-smooth surface profile achieved by the UF6 DIA technology enables manufacturers to avoid diamond slurry costs, reduce chemical mechanical polishing (CMP) cost tremendously and drastically increase throughput.

Semiconductor fabs and equipment suppliers often face challenges in keeping up with the increasingly stringent requirements of cleaning processes. However, a deeper understanding of the physical and sonochemical phenomena in megasonic processing can significantly aid in optimizing processes, improving cleaning efficiency, and ensuring reproducible results.

This presentation not only sheds light on the behavior of sonicated fluids but also debunks enduring myths surrounding megasonic cleaning technologies, providing clearer insights into the true capabilities of this future-proof technology.

The presentation highlights FM4910-certified plastics as a game-changer for semiconductor safety, replacing traditional thermoplastics and semiconductors in critical environments. Thermoplastics are a crucial part of cleanroom equipment (e.g. wet benches including chemical process tanks) and inevitable to use. FM4910 approved thermoplastics go one step further and offer superior fire resistance, low smoke generation, and chemical durability, making them ideal for wet process equipment in cleanrooms. By eliminating the risks associated with thermoplastics, FM4910 plastics enhance operational safety and compliance with stringent industry standards. Their adoption represents a significant step towards safer, more reliable semiconductor production processes.