Compressed gases in semiconductor manufacturing and their high-pressure diffusers

Published: 11-Jun-2024

Unveiling the hidden heroes

Understanding High Pressure Diffusers

High Pressure Diffusers (HPDs) are essential for maintaining the precision of particle counts in compressed gas samples. They act as a link between the particle counter and the compressed gas line, diffusing the gas as it enters the particle counter’s sample inlet. This ensures that the pressure is controlled to prevent any damage to the sensitive internal sensor components of the particle counter’s sample chamber.

Types of High-Pressure Diffusers

There are two primary types of HPDs: Vented Return and Ported Exhaust. Vented Return HPDs release gas into the environment, while Ported Exhaust HPDs safely expel gas outside the testing area. The selection between these types depends on the gas being sampled. Vented Return HPDs are suitable for harmless gases like oxygen, while Ported Exhaust HPDs are typically used for hazardous gases such as flammable ones.

Setting Up Your HPD

Proper installation of your HPD is critical for accurate sampling. It involves securely connecting the HPD between the compressed gas line and the particle counter, ensuring tight fittings and correct airflow direction. Any leaks or incorrect fittings could compromise the integrity of your sampling process.

Fine-Tuning Your Flow Rate

Another essential thing to be aware of is that you will need to achieve the correct flow rate to ensure your sample results. Matching the flow rate of the particle counter with the HPD ensures iso-kinetic sampling, where the airflow remains constant. Adjustments may be necessary based on the gas inlet pressure, and referring to a table for guidance can help optimise your flow rate for accurate sampling.

The Important of Testing Gases in Semiconductor Manufacturing

In semiconductor manufacturing, precision reigns supreme and every element plays a crucial role. Among the unsung heroes of this industry are compressed gases, silently facilitating the intricate process that bring integrated circuits (ICs) to life.

Let’s delve into their indispensable applications:

  • Deposition Processes: Silane, ammonia, and dopant gases enable chemical and physical vapour deposition, forming thin semiconductor layers essential for IC fabrication.
  • Etching: Gases like SF6 and NF3 etch intricate patterns on wafers through plasma and reactive ion etching, removing unwanted material with precision.
  • Doping: Dopant gases like diborane, phosphine, and arsine alter semiconductor materials’ electrical properties, creating crucial p-type or n-type regions.
  • Purging and Cleaning: High-purity nitrogen and argon purge chambers, preventing contamination and ensuring consistent, contaminant-free conditions.
  • Cooling and Temperature Control: Certain gases regulate temperatures during manufacturing, preventing defects caused by thermal stresses.
  • Atmosphere Control: Inert gases stabilise fabrication environments, maintaining process integrity and preventing unwanted reactions.
  • Ion Implantation: Gases like argon and boron trifluoride facilitate ion implantation, altering substrate properties with precision.
  • Lithography Support: Compressed gases maintain clean, stable environments and assist in pneumatic systems crucial for precise machinery movements during lithography.

When it comes to the intricate dance of semiconductor manufacturing, compressed gases are the silent choreographers, orchestrating every step with precision – and their specialised use demands strict control of purity and conditions to meet ISO 8573’s exacting standards, making them integral to the creation of today’s modern ICs.

High Pressure Diffusers may seem complex at first glance, but understanding their importance and proper usage is essential for accurate particle counting. By selecting the appropriate HPD type, setting it up correctly, and fine-tuning the flow rate, you’ll easily be able to ensure reliable and precise results in your gas sampling endeavours.

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