Thermogravimetric approach for determining the degree of conversion in radiation‐polymerized DADMAC

Francis, Sanju; Varshney, Lalit; Mitra, D.; Sabharwal, S.

doi:10.1002/app.28863

Cited by 4 publications

(3 citation statements)

References 14 publications

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“…• C. 20 The reported weight loss data were normalized by subtracting the weight loss of the bare silica and ceria particles.…”

Section: Methodsmentioning

confidence: 99%

“…The temperature of the sample (∼50 mg) was initially raised to 100 • C and maintained there for 30 min to remove any residual moisture and the temperature was then increased to 400 • C at a rate of 15 • C/min while the sample weight was recorded. Decomposition temperature of pure DADMAC is between 175 and 247 • C. 20 The reported weight loss data were normalized by subtracting the weight loss of the bare silica and ceria particles.…”

Section: Methodsmentioning

confidence: 99%

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Ceria-Based Slurries for Non-Prestonian Removal of Silicon Dioxide Films

Korkmaz

Babu

2014

ECS J. Solid State Sci. Technol.

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A slurry with a non-Prestonian dependence on the polishing pressure can help in minimizing dishing and erosion during shallow trench isolation chemical mechanical planarization. Here, we show that ceria-based slurries containing diallyldimethylammonium chloride (DADMAC) yield a non-Prestonian blanket film polish rate with a low threshold pressure (1-2 psi) when polishing plasma-enhanced chemical vapor (PECVD) tetraethylorthosilicate (TEOS) deposited oxide as well as thermal oxide films. The polishing mechanism of this non-Prestonian slurry was investigated by a series of experiments involving zeta potential measurements, thermogravimetric analysis (TGA) and UV-vis spectroscopy and it was shown that more DADMAC molecules are adsorbed on silica particles (as oxide film representatives) than on ceria particles and the binding strength between DADMAC and silica is much higher than that with ceria surface. Shallow trench isolation (STI) is an ubiquitous complimentary metal-oxide semiconductor isolation process technology. Deposition of an isolation stack that contains 3 to 10 nm thick 1,2 thermally grown pad oxide on top of a silicon substrate followed by the deposition of either plasma-enhanced chemical vapor deposition (PECVD) or low-pressure chemical vapor deposition (LPCVD) nitride layer (10 to 30 nm) 1 is the first step in the STI process. In the next step, active areas and isolation fields are determined by patterning the silicon nitride and silicon dioxide pad layers on the silicon substrate, followed by etching of trenches into the silicon substrate using the oxide/nitride stack as a mask. The trenches are then filled with oxide, employing high density plasma-enhanced chemical vapor deposition (PECVD) process using tetraethylorthosilicate (TEOS) as the source of silicon, because of its high gap-filling capacity. The deposited oxide not only fills the trenches but also generates an overfill, which needs to be removed. This is achieved through planarization of the oxide film topography by chemical mechanical planarization (CMP) using a slurry that produces a high oxide and very low nitride removal rates (RRs).In this STI process, major concerns include dishing within the oxide features resulting from over-polish as well as the erosion of the underlying nitride film and, in some cases, the details of the corner rounding near active areas. Therefore, optimization of the CMP process is crucial in order to achieve complete removal of the oxide on top of the nitride film with good planarity and uniformity and to avoid erosion and dishing during the CMP process. 3,4 One method that can be used to minimize dishing and erosion during STI CMP is to control the polishing performance by using a slurry that shows a non-Prestonian polishing behavior. Non-Prestonian behavior occurs when there is a non-linear relationship between applied polishing pressures and resulting polishing rates. Here we consider only the effect of pressure and not that of the rotational velocity on the blanket film polish rates.Several models were di...

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“…• C. 20 The reported weight loss data were normalized by subtracting the weight loss of the bare silica and ceria particles.…”

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Ceria-Based Slurries for Non-Prestonian Removal of Silicon Dioxide Films

Korkmaz

Babu

2014

ECS J. Solid State Sci. Technol.

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“…The initial step of weight loss below 150 °C is due to the loss of water. Next stage, for temperatures between 175 and 280 °C, is the decomposition of unreacted DADMAC 45. The final stage, between 350 °C and 520 °C is due to the polymer decomposition.…”

Section: Resultsmentioning

confidence: 99%

Cationic Copolyelectrolytes: Online Monitoring of the Synthesis and Subsequent Copolymer Characterization

Zheng

Alb

2012

Macro Chemistry & Physics

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Kinetics of copolymerization reactions of diallyldimethylammonium chloride (DADMAC) and dimethyl acrylamide (DMA) in aqueous solvent is studied, with highlights on features that control many aspects of the polymeric materials behavior throughout and post‐synthesis. The aim of this study is twofold; first, to offer a method to study the impact of the incorporation of the cationic DADMAC on the composition drift, molecular mass of the copolyelectrolyte, and on the polyelectrolyte behavior by monitoring in real time the copolymerization reactions with a neutral monomer under different conditions. Additionally, it is meant to make the transition toward the next step, controlling the reaction kinetics during designed semi‐batch experiments designed to achieve the average mass and composition distributions desired.

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