A Direct-Write Single-Step Positive Etch Resist for Dip-Pen Nanolithography

AbstractOrdered carbon nanotube (CNT) growth by deposition of nanoparticle catalysts using dip pen nanolithography (DPN) is presented. DPN is a direct write, tip based lithography technique capable of multi-component deposition of a wide range of materials with nanometer precision. A NanoInk NLP 2000 is used to pattern different catalytic nanoparticle solutions on various substrates. To generate a uniform pattern of nanoparticle clusters, various conditions need to be considered. These parameters include: the humidity in the vessel, temperature, and tip-surface dwell time. By patterning different nanoparticle solutions next to each other, identical growth conditions can be compared for different catalysts in a streamlined analysis process. Fe, Ni, and Co nanoparticle solutions patterned on silicon, mica, and graphite substrates serve as nucleation sites for CNT growth. The CNTs were synthesized by a chemical vapor deposition (CVD) reaction. Each nanoparticle patterned substrate is placed in a tube furnace held at 725°C during CNT growth. The carbon source used in the growth chamber is toluene. The toluene is injected at a rate of 5 mL/hr. Growth is observed for Fe and Ni nanoparticle patterns, but is lacking for the Co patterns. The results of these reactions provide important information regarding efficient and highly reproducible mechanisms for CNT growth.

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Electrical Resistance of Laser Sintered Direct-Write Deposited Materials for Microelectronic Applications

Journal of Microelectronics and Electronic Packaging ◽

10.4071/1551-4897-1.4.261 ◽

2004 ◽

Vol 1 (4) ◽

pp. 261-268 ◽

Cited By ~ 12

Author(s):

Valery R. Marinov

Keyword(s):

Electrical Resistance ◽

Screen Printing ◽

Continuous Wave ◽

New Technology ◽

Single Step ◽

Direct Write ◽

Sintering Process ◽

Heat Treated ◽

Via Holes ◽

Printing Processes

The direct write technology provides an interesting opportunity for plugging blind via holes as a more precise alternative to currently used screen printing processes. This technology provides a complete, void-less filling of the via and fabrication of the interconnects extending from the via in one single step. After deposition, the material is heat treated (sintered) to densify into a highly conductive solid. Sintering is usually accomplished by laser treatment. Some aspects of this relatively new technology, especially these related to the relationships between the laser sintering process and the deposited material properties are still largely unexplored. This paper presents experimental results for the microscale electrical resistance of two silver inks deposited by a direct write method and sintered with a continuous wave Nd:YAG laser. The resistance of the deposited and sintered silver lines and the resistance of the material in the plugged via holes was mapped by the advanced micro four-point probe technique. Results showed that higher laser powers reduce significantly the resistance of the silver inks. The importance of the deposited material sinterability is also emphasized.

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The rational design of a Au(I) precursor for focused electron beam induced deposition

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.8.274 ◽

2017 ◽

Vol 8 ◽

pp. 2753-2765 ◽

Cited By ~ 5

Author(s):

Ali Marashdeh ◽

Thiadrik Tiesma ◽

Niels J C van Velzen ◽

Sjoerd Harder ◽

Remco W A Havenith ◽

...

Keyword(s):

Electron Beam ◽

Rational Design ◽

Solid Phase ◽

Single Step ◽

Steric Effects ◽

Nanometer Scale ◽

Direct Write ◽

High Volatility ◽

The Stability ◽

Aurophilic Interactions

Au(I) complexes are studied as precursors for focused electron beam induced processing (FEBIP). FEBIP is an advanced direct-write technique for nanometer-scale chemical synthesis. The stability and volatility of the complexes are characterized to design an improved precursor for pure Au deposition. Aurophilic interactions are found to play a key role. The short lifetime of ClAuCO in vacuum is explained by strong, destabilizing Au–Au interactions in the solid phase. While aurophilic interactions do not affect the stability of ClAuPMe3, they leave the complex non-volatile. Comparison of crystal structures of ClAuPMe3 and MeAuPMe3 shows that Au–Au interactions are much weaker or partially even absent for the latter structure. This explains its high volatility. However, MeAuPMe3 dissociates unfavorably during FEBIP, making it an unsuitable precursor. The study shows that Me groups reduce aurophilic interactions, compared to Cl groups, which we attribute to electronic rather than steric effects. Therefore we propose MeAuCO as a potential FEBIP precursor. It is expected to have weak Au–Au interactions, making it volatile. It is stable enough to act as a volatile source for Au deposition, being stabilized by 6.5 kcal/mol. Finally, MeAuCO is likely to dissociate in a single step to pure Au.

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