Synthesis of Phosphonic Acid Ligands for Nanocrystal Surface Functionalization and Solution Processed Memristors

Here we synthesize 2-ethylhexyl, 2-hexyldecyl, 2-[2-(2-methoxyethoxy)ethoxy]ethyl, oleyl and n-octadecyl phosphonic acid and use them to functionalize CdSe and HfO2 nanocrystals. In contrast to branched carboxylic acids, post-synthetic surface functionalization of CdSe and HfO2 nanocrystals is readily achieved with branched phosphonic acids. A simple flow coating process is used to deposit ribbons of individual phosphonic acid capped HfO2 nanocrystals, which are subsequently evaluated as a memristor using conductive atomic force microscopy (c-AFM). We find that 2-ethylhexyl phosphonic acid is a superior ligand, combining a high colloidal stability with a compact ligand shell that results in a record-low operating voltage that is promising for application in flexible electronics.

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Hybrid Nanoparticles Prepared by In-situ and Post-synthetic Surface Modification of Lanthanide-Based Nanoparticles with Phosphonic Acid Derivatives

MRS Proceedings ◽

10.1557/proc-1007-s12-02 ◽

2007 ◽

Vol 1007 ◽

Author(s):

Christoph Rill ◽

Sorin Ivanovici ◽

Guido Kickelbick

Keyword(s):

Surface Modification ◽

Phosphonic Acid ◽

Hybrid Nanoparticles ◽

Phosphonic Acids ◽

Force Microscopy ◽

Atomic Force ◽

Transmission Electron ◽

Separate Step ◽

20 Nm

ABSTRACTThe use of various phosphonic acid derivatives – some of which contain polymerizable groups – as surface modifying agents for nanoparticles was studied both in-situ during the synthesis of lanthanide-based (Ln = Nd, Eu, Yb) nanoparticles at room temperature as well as in a separate step after the particle preparation by a hydrothermal method. In the single-pot in-situ method the phosphonic acid esters served as growth-limiting agent during particle formation leading to small nanoparticles with a size of only a few nanometers as determined by dynamic light scattering as well as transmission electron and atomic force microscopy. Free phosphonic acids as well as their silyl esters were used to modify the hydrothermally prepared neodymium hydroxide nanorods which had diameters of approx. 20 nm and a length ranging up to a few micrometers. The surface modification was confirmed by infrared spectroscopy and thermogravimetric analysis.

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Fault Isolation of MOL and FEOL Buried Defects Using Conductive Atomic Force Microscopy as a Complement to Passive Voltage Contrast Imaging

ISTFA 2017: Conference Proceedings from the 43rd International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2017p0606 ◽

2017 ◽

Author(s):

Lucile C. Teague Sheridan ◽

Linda Conohan ◽

Chong Khiam Oh

Keyword(s):

Atomic Force Microscopy ◽

Cmos Technology ◽

Fault Isolation ◽

Contrast Imaging ◽

Conductive Atomic Force Microscopy ◽

Isolation Technique ◽

Conductive Afm ◽

Force Microscopy ◽

Atomic Force ◽

Voltage Contrast

Abstract Atomic force microscopy (AFM) methods have provided a wealth of knowledge into the topographic, electrical, mechanical, magnetic, and electrochemical properties of surfaces and materials at the micro- and nanoscale over the last several decades. More specifically, the application of conductive AFM (CAFM) techniques for failure analysis can provide a simultaneous view of the conductivity and topographic properties of the patterned features. As CMOS technology progresses to smaller and smaller devices, the benefits of CAFM techniques have become apparent [1-3]. Herein, we review several cases in which CAFM has been utilized as a fault-isolation technique to detect middle of line (MOL) and front end of line (FEOL) buried defects in 20nm technologies and beyond.

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Fault Localization in Contact Level by Using Conductive Atomic Force Microscopy

ISTFA 2003: Conference Proceedings from the 29th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2003p0413 ◽

2003 ◽

Author(s):

Jon C. Lee ◽

J. H. Chuang

Keyword(s):

Atomic Force Microscopy ◽

Integrated Circuits ◽

Fault Localization ◽

Electrical Characterization ◽

Conductive Atomic Force Microscopy ◽

Force Microscopy ◽

Atomic Force ◽

Optical Electron ◽

Defect Isolation ◽

Voltage Contrast

Abstract As integrated circuits (IC) have become more complicated with device features shrinking into the deep sub-micron range, so the challenge of defect isolation has become more difficult. Many failure analysis (FA) techniques using optical/electron beam and scanning probe microscopy (SPM) have been developed to improve the capability of defect isolation. SPM provides topographic imaging coupled with a variety of material characterization information such as thermal, magnetic, electric, capacitance, resistance and current with nano-meter scale resolution. Conductive atomic force microscopy (C-AFM) has been widely used for electrical characterization of dielectric film and gate oxide integrity (GOI). In this work, C-AFM has been successfully employed to isolate defects in the contact level and to discriminate various contact types. The current mapping of C-AFM has the potential to identify micro-leaky contacts better than voltage contrast (VC) imaging in SEM. It also provides I/V information that is helpful to diagnose the failure mechanism by comparing I/V curves of different contact types. C-AFM is able to localize faulty contacts with pico-amp current range and to characterize failure with nano-meter scale lateral resolution. C-AFM should become an important technique for IC fault localization. FA examples of this technique will be discussed in the article.

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Application of Conductive-AFM in Soft Failure Analysis

ISTFA 2017: Conference Proceedings from the 43rd International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2017p0327 ◽

2017 ◽

Author(s):

Chuan Zhang ◽

Yinzhe Ma ◽

Gregory Dabney ◽

Oh Chong Khiam ◽

Esther P.Y. Chen

Keyword(s):

Failure Analysis ◽

Conductive Atomic Force Microscopy ◽

Test Parameter ◽

Conductive Afm ◽

Force Microscopy ◽

Analysis Methodology ◽

Soft Failure ◽

Atomic Force ◽

Test Conditions ◽

Sensitive Characteristics

Abstract Soft failures are among the most challenging yield detractors. They typically show test parameter sensitive characteristics, which would pass under certain test conditions but fail under other conditions. Conductive-atomic force microscopy (CAFM) emerged as an ideal solution for soft failure analysis that can balance the time and thoroughness. By inserting CAFM into the soft failure analysis flow, success rate of such type of analysis can be significantly enhanced. In this paper, a logic chain soft failure and a SRAM local bitline soft failure are used as examples to illustrate how this failure analysis methodology provides a powerful and efficient solution for soft failure analysis.

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