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Lessons from the Semiconductor Industry: Enhancing Contamination Control in Isolators and Closed RABS with Advanced Wipers

by | Dec 8, 2023

Image: MiraWIPE cleaning contamination off a biosafety cabinet.

Aseptic pharmaceutical facilities have been turning to Closed Restricted Access Barrier Systems (RABS) and Isolators in the quest for impeccable cleanliness and contamination control. These technologies have been widely adopted due to their effectiveness in reducing viable and nonviable contamination. However, users have reported that wiper fibers remain a persistent contamination source despite these advancements. Drawing lessons from the semiconductor industry’s experience with isolators, we can understand the importance of selecting the right tools for contamination control.

Image: Polyester contamination found inside biosafety cabinet from the facility’s polyester wipes.

The Semiconductor Industry’s Transition

Over two decades ago, the semiconductor industry significantly shifted its manufacturing processes by adopting isolator-like techniques for processing and transferring wafers. This transition was crucial, especially with the introduction of 300mm wafers in 2000. The isolation of wafers from the cleanroom environment was a game-changer in contamination control.

However, isolated wafer processing exposed equipment cleaning as a significant source of contamination. Residues generated during operations, coupled with equipment cleaning, became the dominant source of contamination. 

Challenges with Polyester Wipers

Like aseptic facilities, isolated tooling in the semiconductor industry was cleaned using sealed-edge polyester wipers. However, poor post-PM particle counts and lengthy pump downtimes due to insufficient surface cleanliness and dryness forced wafer fabs to look for an alternative to polyester wipers. Equipment engineers found three significant deficiencies with polyester wipers:

  1. Poor Cleaning Efficacy: Polyester wipers struggled to dislodge and effectively remove stubbornly adhered residues and particles.
  2. Inadequate Surface Drying: Polyester wipers couldn’t leave surfaces dry when wetted with cleaning agents like 70% IPA or 100% water, which are commonly used in semiconductor cleaning processes.
  3. Fiber Release and Abrasion: Polyester wipers exhibited poor abrasion resistance, leading to fiber release during wiping, which could introduce additional contamination.

The Solution: Foamtec’s MiraWIPE

In the past decade, the most advanced wafer fabs in the semiconductor industry have adopted Foamtec’s MiraWIPE. This revolutionary solution addresses the shortcomings of polyester wipers effectively:

  1. Microfiber Fabric: MiraWIPE utilizes a woven microfiber fabric that excels in dislodging, entrapping, and removing stubborn residues and particles from surfaces.
  2. Surface Drying: Unlike polyester, MiraWIPE leaves surfaces dry even when wetted with cleaning fluids like water, IPA, or other solvents, enhancing cleaning efficiency.
  3. Abrasion Resistance: MiraWIPE’s advanced fabric significantly reduces particle and fiber generation during wiping, ensuring a cleaner and more reliable cleaning process.

Sterile and Pre-saturated Options: MiraWIPE is available in clean and pre-saturated versions, making it a versatile solution for various cleanroom applications.


The semiconductor industry’s experience with isolator-like techniques and advanced wiper technology is a valuable lesson in aseptic drug manufacturing facilities. It highlights the importance of selecting the right tools for cleaning and disinfecting closed RABS and Isolators.

Foamtec’s MiraWIPE, with its woven microfiber fabric, superior surface drying capabilities, and abrasion resistance, has proven to be a game-changer in equipment cleaning, ensuring a higher level of cleanliness and reducing contamination risks. As aseptic facilities strive to optimize the operation of aseptic isolators and closed RABS, lessons from the semiconductor industry can guide them in making informed decisions and choosing the best tools for the job.