Application of pressure-cycle purge (PCP) in dry-down of ultra-high-purity gas distribution systems

Yao, Junpin; Wang, Hao; Dittler, Roy; Geisert, Carl; Shadman, Farhang

doi:10.1016/j.ces.2010.06.002

Cited by 4 publications

(2 citation statements)

References 19 publications

(16 reference statements)

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“…The AD characteristics of almost all systems were not inspected because of a lack of a movable trace moisture analyzer (TMA) with sufficient sensitivity and fast response. Although APIMS was an established technique for the evaluation, 9) it was immovable and too expensive to install on-site. Recently, cavity ringdown spectroscopy (CRDS), 1,10) which has a sensitivity comparable to APIMS and is movable, has become commercially available.…”

Section: Introductionmentioning

confidence: 99%

Moisture adsorption desorption characteristics of stainless steel tubing measured by ball surface acoustic wave trace moisture analyzer

Tsuji

Akao

Oizumi

et al. 2017

Jpn. J. Appl. Phys.

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A ball surface acoustic wave (SAW) trace moisture analyzer (TMA) was applied to measuring the adsorption and desorption (AD) characteristics of a stainless steel tube. For the first time, two-frequency measurement for precise temperature compensation was attempted at intervals of 3 s using a burst waveform undersampling circuit. We succeeded in measuring the variations of moisture transit time and dry-down dynamics caused by inner surface treatments such as bright annealing (BA), electropolishing (EP), and electrochemical buffing (ECB) using a sample-tube length of only 100 mm at a flow rate of 0.1 L/min. Net moisture adsorption was evaluated from the measured adsorption subtracted by the background adsorption. As a result, it was found that the adsorption on the ECB tube was smaller than those on EP and BA tubes by 1/3 and 1/4, respectively, at a baseline concentration of 13 ppbv. From these results, it was demonstrated that the ball SAW TMA could be used for measuring the AD characteristics of stainless steel tubes with various surface treatments.

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Section: Introductionmentioning

confidence: 99%

Moisture adsorption desorption characteristics of stainless steel tubing measured by ball surface acoustic wave trace moisture analyzer

Tsuji

Akao

Oizumi

et al. 2017

Jpn. J. Appl. Phys.

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“…Most semiconductor processes are very sensitive to impurities and require a well-controlled quality [3] [4]. Failure to maintain a stable purity level at the (POU) can lower the performance of process tools and even slow or shut down the processing line [5].…”

Section: Introductionmentioning

confidence: 99%

A Controlled Mixing Method for Stabilizing the Purity and Reducing the Waste in Gas Delivery Systems

Wu¹,

Shadman²

2019

ACES

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The variation of impurity concertation in the ultra-high purity (UHP) gases, delivered from cryogenic storage tanks and transported through long pipes, is a major problem in systems like those used in semiconductor manufacturing facilities. A method is developed for stabilizing the purity and reducing the gas consumption in these systems. This technique uses a dynamically controlled mixing of gases supplied by multiple cryogenic tanks. The control scheme uses software modules that simulate the processes that cause purity variation in both the cryogenic tanks and the transport lines. These processes include vaporization and supply in tanks, various modes of transport in delivery pipes, and the adsorption and desorption on surfaces. The method also includes and corrects for variations caused by transience in gas usage rate as well as ambient conditions.

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Pressure cycling for purging of dead spaces in high‐purity gas delivery systems

et al. 2015

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The purging of stagnant or dead volumes in gas distribution systems is an important method for removing impurities and maintaining cleanliness. A combination of experimental investigation and computational process modeling is used to study the dynamics of impurity removal under variety of purge conditions. The controlled cycling of pressure during purge is found to enhance the cleaning process significantly, particularly in dead spaces. The process simulator was used to develop and analyze a pressure‐cyclic purge (PCP) method and understand the conditions that would make PCP advantageous over steady‐state purge (SSP). In particular, the effect of geometric factors, impurity surface interactions, flow rate, and cycle characteristics on PCP and its comparison with SSP was studied. The advantage of the PCP method, in terms of both purge time and gas usage, becomes more pronounced in systems with larger number and size of dead spaces and impurities that interact strongly with the surfaces. © 2015 American Institute of Chemical Engineers AIChE J, 61: 3973–3980, 2015

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Application of pressure-cycle purge (PCP) in dry-down of ultra-high-purity gas distribution systems

Cited by 4 publications

References 19 publications

Moisture adsorption desorption characteristics of stainless steel tubing measured by ball surface acoustic wave trace moisture analyzer

Moisture adsorption desorption characteristics of stainless steel tubing measured by ball surface acoustic wave trace moisture analyzer

A Controlled Mixing Method for Stabilizing the Purity and Reducing the Waste in Gas Delivery Systems

Pressure cycling for purging of dead spaces in high‐purity gas delivery systems

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