Protective coatings of hafnium dioxide by atomic layer deposition for microelectromechanical systems applications

We report the growth of nanoscale hafnium dioxide (HfO2) and zirconium dioxide (ZrO2) thin films using remote plasma-enhanced atomic layer deposition (PE-ALD), and the fabrication of complementary metal-oxide semiconductor (CMOS) integrated circuits using the HfO2 and ZrO2 thin films as the gate oxide. Tetrakis (dimethylamino) hafnium (Hf[N(CH3)2]4) and tetrakis (dimethylamino) zirconium (IV) (Zr[N(CH3)2]4) were used as the precursors, while O2 gas was used as the reactive gas. The PE-ALD-grown HfO2 and ZrO2 thin films were analyzed using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and high-resolution transmission electron microscopy (HRTEM). The XPS measurements show that the ZrO2 film has the atomic concentrations of 34% Zr, 2% C, and 64% O while the HfO2 film has the atomic concentrations of 29% Hf, 11% C, and 60% O. The HRTEM and XRD measurements show both HfO2 and ZrO2 films have polycrystalline structures. n-channel and p-channel metal-oxide semiconductor field-effect transistors (nFETs and pFETs), CMOS inverters, and CMOS ring oscillators were fabricated to test the quality of the HfO2 and ZrO2 thin films as the gate oxide. Current-voltage (IV) curves, transfer characteristics, and oscillation waveforms were measured from the fabricated transistors, inverters, and oscillators, respectively. The experimental results measured from the HfO2 and ZrO2 thin films were compared.

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Atomic Layer Deposition of Hafnium Dioxide Films from Hafnium Tetrakis(ethylmethylamide) and Water

Chemical Vapor Deposition ◽

10.1002/1521-3862(20020903)8:5<199::aid-cvde199>3.0.co;2-u ◽

2002 ◽

Vol 8 (5) ◽

pp. 199-204 ◽

Cited By ~ 124

Author(s):

K. Kukli ◽

M. Ritala ◽

T. Sajavaara ◽

J. Keinonen ◽

M. Leskelä

Keyword(s):

Atomic Layer Deposition ◽

Atomic Layer ◽

Hafnium Dioxide ◽

Layer Deposition

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VERTICAL SILICON NANOWIRES WITH ATOMIC LAYER DEPOSITION WITH HfO2 MEMBRANE FOR pH SENSING APPLICATION

Journal of Mechanics in Medicine and Biology ◽

10.1142/s0219519411004897 ◽

2011 ◽

Vol 11 (05) ◽

pp. 959-966 ◽

Cited By ~ 3

Author(s):

YI-TING LIN ◽

YU-HONG YU ◽

YU CHEN ◽

GUO-JUN ZHANG ◽

SHI-YANG ZHU ◽

...

Keyword(s):

Atomic Layer Deposition ◽

Silicon Nanowires ◽

Atomic Layer ◽

Hafnium Dioxide ◽

Hydrogen Ion ◽

Ion Concentration ◽

Hydrogen Ion Concentration ◽

Sensing Properties ◽

Layer Deposition ◽

Sensing Membrane

Vertical silicon nanowire (SiNW) platforms are candidates for use in ultrasensitive biosensors, with surface-to-volume ratio higher than one-dimensional SiNW . In this paper, a vertical SiNW electrolyte–insulator–semiconductor (EIS) structure with an ALD-HfO2 sensing membrane is proposed for use in a hydrogen ion sensor. Hafnium dioxide is used as the sensing membrane, which was deposited on the surface of the vertical SiNW structure by atomic layer deposition. The sensing properties were examined using a HP4284A high-precision LCR analyzer. A linear relationship was found between the flatband voltage shift and the hydrogen ion concentration. Comparing with different diameters of SiNW , the sensitivity with diameter of 200 nm was slightly higher than 100 nm. A post-deposition rapid thermal annealing (RTA) was utilized to optimize the sensing properties, and the sensitivity was increased to 51.07 mV/pH.

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Atomic Layer Deposition of Hafnium Dioxide on TiN and Self-Assembled Monolayer Molecular Film

Journal of The Electrochemical Society ◽

10.1149/1.3125722 ◽

2009 ◽

Vol 156 (7) ◽

pp. H561 ◽

Cited By ~ 3

Author(s):

Zhong Chen ◽

Smita Sarkar ◽

Nivedita Biswas ◽

Veena Misra

Keyword(s):

Atomic Layer Deposition ◽

Atomic Layer ◽

Hafnium Dioxide ◽

Self Assembled Monolayer ◽

Molecular Film ◽

Layer Deposition ◽

Self Assembled

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Thermal and plasma enhanced atomic layer deposition of ultrathin TiO2 on silicon from amide and alkoxide precursors: growth chemistry and photoelectrochemical performance.

Journal of Physics D Applied Physics ◽

10.1088/1361-6463/ac360c ◽

2021 ◽

Author(s):

Shane O'Donnell ◽

Feljin Jose ◽

Kyle Shiel ◽

Matthew Snelgrove ◽

Caitlin McFeely ◽

...

Keyword(s):

Atomic Layer Deposition ◽

Photoelectron Spectroscopy ◽

Protective Coatings ◽

Low Cost ◽

Atomic Layer ◽

Photoelectrochemical Cell ◽

Photoelectrochemical Performance ◽

Tio2 Thin Films ◽

Carbon Incorporation ◽

Layer Deposition

Abstract Due to its low cost and suitable band gap, silicon has been studied as a photoanode material for some time. However, as a result of poor stability during the oxygen evolution reaction (OER), Si still remains unsuitable for any extended use. Ultra-thin titanium dioxide (TiO2) films have been used as protective coatings and are shown to enhance Si photoanode lifetime with added solar to hydrogen (STH) performance improvements through distancing the oxidation reaction away from the Si photoanode surface and improved charge transport through the anode. This study details the nucleation, growth chemistry, and performance of TiO2 thin films prepared via thermal and plasma enhanced atomic layer deposition (ALD) using both titanium isopropoxide (TTIP) and Tetrakis(dimethylamido)titanium (TDMAT) as the precursor material. The effect of post ALD treatments of plasma and air annealing was also studied. Films were investigated using photoelectrochemical cell testing to evaluate photoelectrochemical performance, and in-vacuum cycle-by-cycle x-ray photoelectron spectroscopy (XPS) was used as the primary characterisation technique to study nucleation mechanisms and film properties contributing to improvements in cell performance. TiO2 grown by plasma enhanced ALD results in cleaner films with reduced carbon incorporation. However, despite increased carbon incorporation, thermally grown films showed improved photocurrent as a result of oxygen vacancies in these films. Post deposition annealing in a H2 ambient is shown to further improve photocurrent in all cases, while annealing in atmosphere leads to uniform film chemistry and enhanced photocurrent stability in all cases.

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