Cleaning and Damage Performance of Single Wafer Cleaning Tools using Physical Removal Forces

Pacco, Antoine; Halder, Sandip; Kenis, Karine; Bearda, Twan; Mertens, Paul

doi:10.1149/1.3202668

Cited by 4 publications

(4 citation statements)

References 7 publications

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“…If f R is assumed to be constant over time, it can be shown that PRE is an exponential decay function of time [3]. In Figure 3 we give the boxplots of the averaged removal rates f R as a function of the radial positions R. It appears that f R increases almost linearly with the radial distance from the wafer center and then reaches a plateau from approximately R=40 mm.…”

Section: Resultsmentioning

confidence: 97%

“…was determined by haze measurements using a KLA SP2 tool with a spatial resolution of 0.6 mm, where σ o and σ(t) are used to denote the initial and instantaneous particle surface concentrations respectively [1,3].…”

Section: Methodsmentioning

confidence: 99%

“…To study the particle removal rate and its uniformity across the wafer, it is necessary to determine the local dwell time of spray cleaning accurately. In a previous work [3], dwell time is estimated by assuming a piecewise constant scanning speed of the nozzle. In this work, we improve the previous model by taking into account the actual speed of the arc scanning nozzle and calculate the dwell time numerically.…”

Section: Dwell Time Calculationmentioning

confidence: 99%

See 2 more Smart Citations

Uniformity of Particle Removal by Aerosol Spray

Pacco²,

Wada

et al. 2012

SSP

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In this work the dynamics of particle removal by aerosol spray is investigated. Local dwell time of spray cleaning is calculated numerically from the process conditions, and some striking topological similarities between the particle removal efficiency and dwell time profiles are observed. The particle removal rates, defined as the normalized speed of particle removal, are not constant during a typical process, with the highest removal rate for the first tens of milliseconds and a temporal decay as time elapses. Increasing N2flow rate results in an enhancement in both the particle removal efficiency and the particle removal rate.

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Section: Resultsmentioning

confidence: 97%

Section: Methodsmentioning

confidence: 99%

Section: Dwell Time Calculationmentioning

confidence: 99%

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Uniformity of Particle Removal by Aerosol Spray

Pacco²,

Wada

et al. 2012

SSP

Self Cite

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“…The nanopatterns on the 300 mm silicon substrates are periodic silicon lines with 30 nm linewidth and 500 µm spacing. The silicon lines have an high K-metal gate interface (HfO 2 /Al 2 O 3 /TiN) and are 100 nm high and 1 mm long (9)(10)(11). The wafers were measured using a brightfield inspection tool (KLA2835) before and after controlled contamination and after clean.…”

Section: Experimental Methodsmentioning

confidence: 99%

A Study of Nanoparticle Removal on Patterned Surfaces

Pacco¹,

Holsteyns²,

Gendt

2013

ECS Trans.

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In this paper a novel method is presented whereby both the damage and the particle removal efficiency on one patterned substrate can be assessed. The method is based on defect inspection by an automated brightfield inspection tool and its successive defect classification. In order to evaluate the method, a representative and common cleaning technique, aerosol spray cleaning, was used. The performance of this method was compared with particle removal efficiency evaluation on non-patterned substrates. Interestingly, particle removal efficiencies on patterned surfaces were much lower than on blanket silicon wafers.

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Enhancement of cavitation activity and particle removal with pulsed high frequency ultrasound and supersaturation

Hauptmann

Frederickx

Struyf

et al. 2013

Ultrasonics Sonochemistry

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Megasonic cleaning as applied in leading edge semiconductor device manufacturing strongly relies on the phenomenon of acoustic cavitation. As the occurrence of acoustic cavitation is incorporating a multitude of interdependent effects, the amount of cavitation activity in the cleaning liquid strongly depends on the sonication conditions. It is shown that cavitation activity as measured by means of ultraharmonic cavitation noise can be significantly enhanced when pulsed sonication is applied to a gas supersaturated liquid under traveling wave conditions. It is demonstrated that this enhancement coincides with a dramatic increase in particle removal and is therefore of great interest for megasonic cleaning applications. It is demonstrated that the optimal pulse parameters are determined by the dissolution time of the active bubbles, whereas the amount of cavitation activity depends on the ratio between pulse-off and pulse-on time as well as the applied acoustic power. The optimal pulse-off time is independent of the corresponding pulse-on time but increases significantly with increasing gas concentration. We show that on the other hand, supersaturation is needed to enable acoustic cavitation at aforementioned conditions, but has to be kept below values, for which active bubbles cannot dissolve anymore and are therefore lost during subsequent pulses. For the applicable range of gas contents between 100% and 130% saturation, the optimal pulse-off time reaches values between 150 and 340 ms, respectively. Full particle removal of 78 nm-diameter silica particles at a power density of 0.67 W/cm(2) is obtained for the optimal pulse-off times. The optimal pulse-off time values are derived from the dissolution time of bubbles with a radius of 3.3 μm and verified experimentally. The bubble radius used in the calculations corresponds to the linear resonance size in a 928 kHz sound field, which demonstrates that the recycling of active bubbles is the main enhancement mechanism. The optimal choice of the pulsing conditions however is constrained by the trade-off between the effective sonication time and the desire to have a sufficient amount of active bubbles at lower powers, which might be necessary if very delicate structures have to be cleaned.

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Cleaning and Damage Performance of Single Wafer Cleaning Tools using Physical Removal Forces

Cited by 4 publications

References 7 publications

Uniformity of Particle Removal by Aerosol Spray

Uniformity of Particle Removal by Aerosol Spray

A Study of Nanoparticle Removal on Patterned Surfaces

Enhancement of cavitation activity and particle removal with pulsed high frequency ultrasound and supersaturation

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