Ellipsometric Porosimetry of Porous Low-k Films with Quazi-Closed Cavities

2004 ◽  
Vol 812 ◽  
Author(s):  
Mikhail R. Baklanov ◽  
Konstantin P. Mogilnikov ◽  
Jin-Heong Yim
Keyword(s):  
Positron Annihilation ◽  
Energy Barrier ◽  
Positron Annihilation Lifetime Spectroscopy ◽  
Ellipsometric Porosimetry ◽  
Positron Annihilation Lifetime ◽  
Short Lifetime ◽  
Sem And Tem ◽  
Comprehensive Information ◽  
Low K ◽  
Good Agreement

AbstractEvaluation of quasi-closed cavities connected with air through narrow necks is discussed. These cavities behave as closed pores when they are studied by Positron Annihilation Lifetime Spectroscopy (PALS). The reason is a short lifetime of o-positronium (Ps) and energy barrier that exist for Ps diffusion from large pores (d>3 nm) to small ones (d<3 nm). It is shown that more comprehensive information can be obtained using adsorption porosimetry. Standard adsorptives used in adsorption porosimetry have infinite lifetime allowing complete penetration and filling all the cavities during the measurement. Calculation of the neck and cavity sizes is based on the theory of metastable adsorption phases developed by Derjagin, Broekhoff and de Boer (DBdB). Results of evaluation are in good agreement with data obtained by SEM and TEM.

scholarly journals Probing diffusion barrier integrity on porous silica low-k thin films using positron annihilation lifetime spectroscopy

2001 ◽  
Vol 89 (9) ◽  
pp. 5138-5144 ◽  
Author(s):  
Jia-Ning Sun ◽  
David W. Gidley ◽  
Terry L. Dull ◽  
William E. Frieze ◽  
Albert F. Yee ◽  
...  
Keyword(s):  
Thin Films ◽  
Positron Annihilation ◽  
Diffusion Barrier ◽  
Porous Silica ◽  
Positron Annihilation Lifetime Spectroscopy ◽  
Barrier Integrity ◽  
Positron Annihilation Lifetime ◽  
Low K

scholarly journals Open Porosity and Pore Size Distribution of Mesoporous Silica Films Investigated by Positron Annihilation Lifetime Spectroscopy and Ellipsometric Porosimetry

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3371
Author(s):  
Bangyun Xiong ◽  
Jingjing Li ◽  
Chunqing He ◽  
Jiale Lai ◽  
Xiangjia Liu ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Positron Annihilation ◽  
Open Porosity ◽  
Positron Annihilation Lifetime Spectroscopy ◽  
Silica Films ◽  
Ellipsometric Porosimetry ◽  
Positron Annihilation Lifetime

Tunable mesoporous silica films were prepared though a sol-gel process directed by the self-assembly of various triblock copolymers. Positron annihilation γ-ray energy spectroscopy and positron annihilation lifetime spectroscopy (PALS) based on intense pulsed slow positron beams as well as ellipsometric porosimetry (EP) combined with heptane adsorption were utilized to characterize the open porosity/interconnectivity and pore size distribution for the prepared films. The consistency between the open porosities was examined by the variations of orthopositronium (o-Ps) 3γ annihilation fractions and the total adsorbed volumes of heptane. The average pore sizes deduced by PALS from the longest-lived o-Ps lifetimes are in good agreement with those by EP on the basis of the Barrett–Joyner–Halenda model, as indicated by a well fitted line of slope k = 1. The results indicate that the EP combined with heptane adsorption is a useful method with high sensitivity for calibrating the mesopore size in highly interconnected mesoporous films, whereas PALS is a novel, complementary tool for characterizing both closed and open pores in them.

Positron Annihilation Lifetime Spectroscopy (Pals) Application in Metal Barrier Layer Integrity for Porous Low-K Materials

2001 ◽  
Vol 686 ◽  
Author(s):  
Simon Lin ◽  
Jia-Ning Sun ◽  
David W. Gidley ◽  
Jeffrey T. Wetzel ◽  
K.A. Monnig ◽  
...  
Keyword(s):  
Pore Size ◽  
Positron Annihilation ◽  
Barrier Layer ◽  
Large Scale ◽  
Positron Annihilation Lifetime Spectroscopy ◽  
Small Scale ◽  
Barrier Integrity ◽  
Positron Annihilation Lifetime ◽  
Low K ◽  
Metal Barrier

AbstractPositron Annihilation Lifetime Spectroscopy (PALS) (1, 2) is a useful tool to pre-screen metal barrier integrity for Si-based porous low-k dielectrics. Pore size of low-k, thickness of metal barrier Ta, positronium (Ps) leakage from PALS, trench sidewall morphology, electrical test from one level metal (1LM) pattern wafer and Cu diffusion analysis were all correlated. Macro-porous low-k (pore size >= 200A) and large scale meso-porous low-k (>50∼200A) encounter both Ps leakage and Cu diffusion into low-k dielectric in the 0.25μmL/0.3μmS structures when using SEMATECH in-house PVD Ta 250A as barrier layer. For small scale meso-porous (>20∼50A) and micro-porous (<=20A) low-k, no Ps leakage and no Cu diffusion into low-k were observed even with PVD Ta 50A, which is proved also owing to sidewall densification to seal all sidewall pores due to plasma etch and ash. For future technology, smaller pore size of porous Si-based low-k (=< 50A) will be preferential for dense low-k like trench sidewall to avoid metal barrier integrity due to coverage problems from sidewall pores.

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