5 Reasons Why Defect Reduction Is Critical In Semiconductor Material Success

Semiconductors may be small, but the impacts they have are significant. Semiconductors used in life-dependent applications, such as pacemakers, defibrillators, life support systems, automotive safety systems, or in aviation need to be fail-proof. A device smaller than a centimeter with features just a few nanometers has no margin of error. This blog shares why it’s important to detect material impurities and explains some of the most common ways to address impurities both within the fab and the supply chain.

Five reasons why detecting material impurities is important

1. Semiconductor performance: Impurities in materials used for semiconductor fabrication can have a detrimental impact on the performance and reliability of the resulting electronic devices. Even trace amounts of impurities can affect the electrical properties and overall functionality of the semiconductors. By reducing material impurities, fabs can produce higher-quality and more reliable chips.
2. Yield and cost improvement: Impurities can contribute to defects and failures during the semiconductor manufacturing process. These defects can lead to a lower yield, meaning a higher percentage of manufactured chips are non-functional or of poor quality. By minimizing impurities, fabs can improve their yield, resulting in more usable chips and higher profitability. Not to mention the significant cost of error. Silicon Expert recently shared that TSMC’s wafers with 3-nm node technology will be priced at $20,000 apiece. With wafers being typically processed together in lots of 25, an impurity could amount 6to losses of millions of dollars. Advancements in EUV illustrate the necessity for defect reduction, as even a part-per-billion defect can cause 10% yield loss.
3. Consistency and repeatability: Fabs aim to achieve consistent and repeatable manufacturing processes to ensure uniformity across batches of chips. Material impurities can introduce variability, making it difficult to achieve consistent results. By controlling and reducing impurities, fabs can enhance the predictability and repeatability of their fabrication processes, leading to more consistent chip performance.
4. Device miniaturization: As semiconductor devices continue to shrink in size and feature size, the impact of impurities becomes more critical. Even smaller concentrations of impurities can cause significant issues at the nanoscale. Fabs must maintain stringent purity standards to meet the requirements of advanced semiconductor technologies, such as those used in hybrid bonding applications that require pitches below 10 µm.
5. Reliability and lifespan: Impurities can adversely affect the long-term reliability and lifespan of semiconductor devices. They can lead to device degradation, premature failure, and increased susceptibility to various failure mechanisms such as electromigration or delamination. By minimizing impurities, fabs can enhance the overall reliability and durability of the fabricated chips.

Brewer Science is reducing defects from the start, right from material selection, and how that plays a critical role leading the way in EUV underlayer materials.

The reduction of material impurities in fabs is critical to ensure high-quality semiconductor devices with improved performance, yield, consistency, and reliability, especially as technology advances and chip sizes shrink. To achieve this, Brewer Science has identified and successfully implemented techniques on the fab level and across the supply chain that reduce material impurities. These lessons are fundamental in our Zero Defects Program, a mindset established from the beginning of development to deliver the highest-quality commercial products.

Reducing impurities in fabs

Reducing impurities in fabs requires a comprehensive look at the material characteristics through a process called fingerprinting.

Fingerprinting

Fingerprinting is the first step in a larger, robust quality management system. The goal is to have an in-depth understanding and relationship across the supply chain from subsuppliers to customers to improve quality and minimize disruptions.

Fingerprinting allows us to have complete characterization of the raw material, making it easier to be consistent across suppliers without influencing the end product. We take the key characteristics from the fingerprint and perform a daily inspection of all new incoming lots for production and look for any excursions, when any of the key characteristics are out of their analytically defined ranges. When there’s an excursion, we go back to the complete fingerprint and compare all characteristics. This process spans beyond excursions management or deviation of quality – it is also used for continuous improvement and our development program. This is a critical step in our basic overview of the three steps to achieve zero defects.

Metrology

A key component of fingerprinting is metrology. Metrology provides the complete material analysis necessary to assign a fingerprint. There are many different techniques to inspect a material using metrology. Our advanced analytic and testing services offer a range of different state-of-art tools, combined with technical expertise, however the offerings can be put into two main categories.

Chemical testing requires evaluating a material’s chemical makeup. We use markers in our fingerprinting to highlight important aspects of each material. We also evaluate each raw material’s consistency and investigate more if they show change. We understand the product formulations and the product chemistry to see if we need to account for changes in the final product.

Physical testing assesses how the material performs. We evaluate whether it performs as expected and look at the final product for any imperfections. A standard methodology is post-coat defect analysis, which involves coating silicon wafers with our product and looking for any flaws in the coating, down to as small as 20nm. We size, count, image, and classify the defects by type to create a defect baseline. We are currently exploring new technologies to advance our capabilities and understanding to take materials to new measures, passing parts per trillion (PPT) and aiming for parts per quadrillion (PPQ).

Brewer Science is utilizing both chemical and physical metrology to refine our processes and products to reduce defects.

Reducing impurities in the supply chain

By fingerprinting materials as they come into the manufacturing process, those characteristics can be applied across the supply chain to improve supplier development, decrease lead times, add value to the customer, and minimize risk. We achieve this through a diligent approach to Supplier Quality Excursion Response.

Supplier quality excursion response

An efficient excursion response detects the excursion promptly, reviews the supply chain, and applies structured problem solving to address the excursion. Therefore, when an excursion happens, the supply chain is not starting from scratch and can rely on previous material knowledge. Because we already have the fingerprint of the material, information can easily be gleaned that allows the supply chain to be in control faster, minimizing downtime and impact to customers.

There is a multi-step process to ensure all aspects of the process and supply chain are considered during an excursion response, these steps include:

• Material excursion triggers the response by detecting differences in the final products.
• Supply chain reviews are conducted to determine where the deviation originated.
• Structured problem solving is required based on the material that was involved, the excursion that was detected, and the level of impact it causes.
• Fingerprint comparison data is reviewed for raw materials to investigate the suspected raw material.
• Supplier develops new testing methods based on existing material data from deep dive into our material and sub-supplier data.
• Supplier educates sub-suppliers to determine best future action. Tests are added to sub-supplier certificate of analysis.

Brewer Science is continually seeking ways to minimize defects and increase efficiency to better serve customers with a complete solution. We have found the best way to offer quality materials that surpass customer expectations is by continually innovating our approach to defect reduction. Our Zero Defect Program enables a higher-level of thinking about our quality standards, ensuring we are being diligent in our tracking, effective in our communication with supply chain partners, and providing our customers with reliable materials.