Ultra-High Purity (UHP) Electronic Gas Analyzers in Semiconductor Industry

In recent years, the growth of the semiconductor industry globally has been driven largely by demand from electronics such as smartphones and the proliferation of applications including the Internet of Things (IoT) and cloud computing. The continued development of existing products, inclusion of emerging technology such as AI in solutions and 5G networks, and the rapid growth in automotive and industrial electronics are also some of the market’s key driving forces. Semiconductors have powered technologies that enrich the lives of consumers and enable businesses and enterprises to operate faster, smarter and more efficiently.

Need for electronic gas analyzers in the semiconductor industry

The semiconductor industry is one of the most dynamic, sophisticated, and competitive global markets. As the industry continues to grow, so too does the demand for ultra-high pure gases and chemicals. For example, 80,000 – 100,000 Nm³/h of Nitrogen with 99.999% purity is required for a 3D NAND fab. Nitrogen, amongst other bulk gases such as oxygen, argon, hydrogen, helium, carbon dioxide and bulk ESGs are essential at every process step and tool for semiconductor and display manufacturing.¹

It is recognized that gas impurities may be detrimental to device processing and performance. Impurities can absorb at the surface of wafers and affect the properties of subsequently grown layers, as illustrated by the influence of organic contamination on the integrity of gate oxides and on the thickness reproducibility of thin silicon nitride layers. Impurities absorbed in the bulk of layers presenting micropores can alter their properties, as with moisture absorption in low dielectrics, and can cause device reliability problems …²

Wafer impurities in the semiconductor fab

Wafer contamination could cost semiconductor companies production wastage, delay in supply, production line suspension and loss in revenue. Two such cases were reported in 2019 where major semiconductor companies had to scrap hundreds of thousands of wafers and faced millions of dollars in revenue loss. Therefore, strict procedures and quality control measures are taken to ensure that ultra-high-purity gases and chemicals are delivered to the manufacturing process.

In the semiconductor wafer fab, organic gas impurities are measured in the QA/QC stage either in the form of Thermal Desorption (TD), Inductively Coupled Plasma (ICP) or Atmospheric Pressure Ionization (API).³ Atmospheric Pressure Ionization Mass Spectrometry (API-MS) is a novel form of mass spectrometry in which the ionization process is carried out in a reaction chamber external to the mass analyzer region. The mass analyzer serves as a device to detect positive or negative ions present in the reaction chamber, which is maintained at atmospheric pressure.⁴

Ultra-high purity (UHP) electronic gas analyzers

Ultra-High Purity (UHP) Electronic Gas Analyzers combine atmospheric pressure ionization mass spectrometry (API-MS) with advanced electronics and software that facilitates routine continuous measurement of contaminants of bulk gases. These gas analyzers allow each bulk gas to be monitored for a range of potential contaminants, while achieving lower detection limits.⁵ This technology is the preferred method for ppt (parts per trillion) level detection in the applications of UHP Nitrogen, UHP Argon, UHP Helium and UHP Hydrogen.

¹https://siliconsemiconductor.net/article/106824/Invisible_Materials_On-site_Bulk_Gas_Supply_To_Semiconductor_And_Display_Fabs/feature

²https://www.researchgate.net/publication/3283816_Wafer_thermal_desorption_spectrometry_in_a_rapid_thermal_processor_using_atmosheric_pressure_ionization_mass_spectrometry

³https://www.thermofisher.com/sg/en/home/industrial/manufacturing-processing/manufacturing-processing-learning-center/electronics-information/semiconductor-analysis-imaging-metrology-information/semiconductor-fabrication-overview.html#semiconductor-solutions

⁴ D. I. Carroll, I. Dzidic, E. C. Horning & R. N. Stillwell (1981) Atmospheric Pressure Ionization Mass Spectrometry, Applied Spectroscopy Reviews, 17:3, 337-406, DOI: 10.1080/05704928108060409 https://www.tandfonline.com/doi/abs/10.1080/05704928108060409

⁵ https://www.thermofisher.com/order/catalog/product/APIMSXANLYZ?SID=srch-srp-APIMSXANLYZ#/APIMSXANLYZ?SID=srch-srp-APIMSXANLYZ