Resources

A discussion about semiconductor facilities’ environmental footprint in relation to water consumption, energy usage, and site selection considerations.

Current "one-pass" industry practices around generation and application of hot ultra-pure water (hot-UPW) consume large amounts of energy to generate the hot-UPW input, and also use the resulting water inefficiently. This presentation showcases engineered solutions to improve efficiency of hot-UPW water use, greatly reducing consumption of hot UPW without any impact to the process.

Despite the technological advancements in online analytical metrologies for ultrapure water (UPW) quality monitoring, offline measurements of grab samples are critical to assess certain quality parameters to date not yet available for online analyzers (i.e. metals and ions). The current recommendations from IRDS (2021 yield enhancement) for metals in UPW to is <1 ppt, for critical metals for image sensors even <0.2 ppt at POP. Therefore, high performance analytics is required in terms of limit of quantification and analytical range. To be able to reliably measure such low concentrations of metals in grab samples, clean sampling strategies are absolutely required to avoid cross contamination onsite. In this work, we present a simple and effective tool helping to bring the samples from the facility to the lab in a clean and reliable way, minimizing main cross-contamination normally occurring during sampling in an industrial environment.

Modern semiconductor devices face tremendous manufacturing challenges due to the ever increasing complexity of the device. In today's most advanced fabs, bulk gases, such as nitrogen, oxygen, argon, helium etc., which are used throughout the manufacturing process have to meet sub-part-per-billion (ppb) impurity specifications; however, semiconductor companies constantly push for lower limits and therefore demand improved analytical devices. At the same time, systems should be low on maintenance and operating costs. For instance, helium carrier gas required by sub-ppb gas chromatographs (GCs) is a huge cost factor that fabs seek to eliminate.

As AMCs originate from a wide variety of sources – including process chemicals, refrigerants, cleaning solvents, construction materials, and personnel - it is critical that any monitoring solution is capable of detecting a robust variety of AMCs. Technologies such as GC, IC, and CRDS are currently limited to a subset of AMC at detection limits which are no longer suitable for the ever-shrinking technology nodes produced in modern FABs because they are unable to provide fast measurements, guarantee a comprehensive monitoring of the AMCs including unknowns, and/or are not sensitive enough to trace contaminants at relevant levels. In this work, the Vocus ABC monitor is presented as a recent technological solution that enables custom lists of compounds to be monitored with a sensitivity that reaches single digit parts-per-trillion volume concentration.

Urea is chemical widely used as nitrogen fertilizer and feed supplement. It is nonvolatile, difficult to oxidize, non-ionic, and highly soluble in water and has a low molecular weight (60 g/mol). Conventional ultrapure water purification techniques are not able to remove it from UPW, and it is a common contaminant in every water reclaim system. Urea naturally decomposes into ammonia, that even at part per billion concentrations, may negatively impact the performance of the acid-catalyzed, chemically amplified photoresists used in today’s DUV photolithography processes. Due to the increasing demand for high quality UPW in the semiconductor industry with tight specs and need to promote water conservation, it is important to treat urea in UPW

TOC in UPW remains a challenge and additional info such as provided with LC-OCD should help to further improve UPW quality in respect to organics. it will be very difficult to get to 0.1 ppb TOC. The reason is manifold but depends partly on the quality of the town water. The impact of the city water is often overlooked, and identical treatment plants are installed irrespective of the local city water situation.

Nanoparticles represent one of the most critical contaminations in ultrapure supplies for semiconductor fabrication addressing ultrapure water (UPW), gasses and chemicals as well as materials of construction decreasing yield on the wafer. Along the UPW generation process, there are sources (e.g. materials) and sinks (e.g. filter) for nanoparticles. As final barrier for nanoparticles in the polishing step, ultrafilters are commonly used on UPW plants. However, the performance of the ultrafilters in the field in terms of removal performance for particles need to be investigated to come up with pro-active approaches for particle removal. Especially for UPW, there is a lack of online particle metrologies down to particle size of sub 50 nm. This study aims to give an overview on different particle metrologies to better understand the particle removal performance by ultrafilters on the market.

Particle contamination in ultrapure water (UPW) remains a high challenge in yield enhancement to achieve more functional die per wafer. IRDS requirement on acceptable particle size in UPW is getting more stringent year by year as semiconductor technology advances. Besides native particles, IRDS also shows growing concern on particle precursors such as dissolved molecular compound which may form solid particles when dried on wafer surface. Our study on the particle types released through a UPW system and its comparison to those found on wafers helps us identify the target particles and particle precursors to be removed from UPW. One of the target process consumables to be studied on the release of particles and particle precursors to UPW is ion exchange resin. Through our investigation on two different ion exchange resins, resin selection is shown to be critical in reducing the release of particles and particle precursors in both short and long terms.

Critical feature sizes of modern semiconductor devices have surpassed the capabilities of traditional optical-based methods to measure particle concentrations in process chemicals and on wafers. Without adequate metrology for quantifying particle and particle precursor concentration in process chemicals, device makers face challenges correlating component failures and fabrication steps. This is especially true for organic material released by Final Polish Ion Exchange resin during a rinse cycle, which is not detected efficiently using optical methods. In this work, we describe two state-of-the-art measurement methods that can detect organic particles and particle precursors to 3 nm using Aerosolization and Threshold Particle Counting (TPC) and defects from UPW deposited on a wafer surface down to 8 nm using Surfaced Enhanced Particle Sizing (SEPS)