Atomic vapor depositions of metal insulator metal capacitors [Elektronische Ressource] : investigation, development and integration / von Mindaugas Lukošius

. . Seeboorapha

Informations

• Publié par: carl_von_ossietzky_universitat_oldenburg
• Publié le: 01 janvier 2010
• Nombre de lectures: 9
• Langue: English
• Poids de l'ouvrage: 13 Mo

Extrait

Atomic Vapor Depositions of Metal
Insulator Metal capacitors: Investigation,
Development and Integration



Von der Fakultät für Mathematik und Naturwissenschaften der Carl von
Ossietzky Universität Oldenburg zur Erlangung des Grades und Titels


Doctor rerum naturalium (Dr. rer. nat.)


Angenommene Dissertation


von Herrn Mindaugas Lukošius


geboren am 20.10.1981 in Panevezys (Litauen)








Gutachterin: Prof. Dr. Katharina Al-Shamery
Gutachter: Dr. habil. Christian Wenger



Tag der Disputation: 12.03.2010



Abstract

Metal-Insulator-Metal (MIM) capacitors are one of the most essential passive
components in radio frequency devices and analog/mixed-signal integrated circuits.
However, depending on the applications, MIM capacitors can require up to 50 % of the
chip area. This strongly affects the ability to reduce the size of the chips, but the reduction
and downscaling of the chips are crucial in order to reduce the cost, and therefore increase
the functionality and performance of the devices. To achieve a higher capacitance per unit
area for providing the analog scaling is the main objective. Since capacitance is a direct
function of the dielectric constant of the insulator, the replacement of currently used silicon
oxide or silicon nitride films with the new alternative dielectrics which have higher
permittivity values is a very promising approach.
The work is focused on the preparation and characterization of alternative
dielectrics, namely HfO , SrTaO and TiTaO as well as of TiN electrode. The study showed 2
that these dielectrics are very promising materials for future Si based technologies.


Metall-Isolator-Metall (MIM) Kondensatoren gehören zu den wichtigsten
passiven Komponenten in Hochfrequenzbauelementen und Schaltkreisen für
Analog/Mischsignale. Unabhängig von der Anwendung beanspruchen MIM-
Kondensatoren bis zu 50 % der Chipfläche. Dies unterstützt maßgeblich die Chipfläche zu
reduzieren, die stark die Kosten aber auch die Funktionalität und Leistung des Chip
bestimmt. Eine Steigerung der Kapazität pro Fläche (Kapazitätsdichte) ist aus diesem
Grund der Schwerpunkt bei der weiteren analogen Skalierung von Bauelementen. Weil die
Kapazität eine direkte Funktion der Dielektrizitätskonstante des Isolators ist, ist das
Ersetzen des gegenwärtig genutzten Siliziumoxid oder Siliziumnitrid durch alternative
Dielektrika mit höheren Dielektrizitätskonstanten ein vielversprechender Ansatz.
Die vorliegende Arbeit ist hauptsächlich auf die Präparation und
Charakterisierung solcher alternativer Dielektrika, wie HfO , Sr-Ta-O und Ti-Ta-O sowie 2
dazugehöriger TiN -elektroden gerichtet. Die durchgeführten Untersuchungen zeigten, dass
diese Dielektrika aussichtsreiche Materialien für zukünftige siliziumbasierte Technologien
darstellen können.

1Acknowledgments

Firstly, I would like to thank the IHP and its Materials Research
Department for providing me the possibility to make my PhD in this
state-of-art Research Institute.

I am genuinely thankful for my supervisor at IHP,
Dr. habil. Christian Wenger, for the guidance, suggestions,
conversations, patience and every other kind of help throughout all the
time during this thesis.

My special thanks go to Prof. Dr. Katharina Al-Shamery at the
University of Oldenburg for accepting my candidature as a PhD student
and for all the support at the University.

I would like to express my gratitude to all the colleagues form the
|Materials Research Department, who contributed and supported my
work, especially Dr. Thomas Schröder for the useful suggestions and
discussions, and my good friend and office colleague Dr. Alessandro
Giussani for the helpful conversations the through all these years.

I would also like to thank Dr. Sergej Pasko from Aixtron AG for
his sincere transfer of knowledge about Atomic Vapor Deposition
technology during the first year of my thesis.

Last but not the least, I am saying huge thank you for my family:
my wonderful wife and my parents who made my entire education
possible.










2Table of Contents

List of abbreviations......................................................................................................... 6
Overview........................................................................................................................... 8
Goal of the study............................................................................................................... 8
Organization of the thesis ............................................................................................. 10
Chapter I......................................................................................................................... 11
1. Introduction ................................................................................................................. 11
1.1. MIM Capacitors ......................................................................................................... 11
1.1.1. Capacitance Voltage Linearity............................................................................ 15
1.1.2. Leakage current................................................................................................... 17
1.1.3. Breakdown Voltage and reliability ..................................................................... 18
1.1.4. Quality factor ...................................................................................................... 20
1.2. Alternative high–k dielectrics.................................................................................... 22
1.2.1. HfO .................................................................................................................... 23 2
1.2.2. Ta O ................................................................................................................... 25 2 5
1.2.3. Sr–Ta–O system.................................................................................................. 26
1.2.4. Ti–Ta–O system 28
1.2.5. Multilayers of dielectrics 29
1.3. 3D architectures.......................................................................................................... 31
1.4. TiN and TaN electrodes ............................................................................................. 33
1.5. Deposition method ...................................................................................................... 36
1.5.1. AVD Technology................................................................................................ 36
Chapter II....................................................................................................................... 41
2. Experimental ............................................................................................................... 41
2.1. Tricent AVD Tool ....................................................................................................... 41
2.2. Precursors ................................................................................................................... 43
2.2.1. Tetrakis(diethylamido)Titanium (TDEATi) ....................................................... 44
2.2.2. Tetrakis(ethylmethylamido) Hafnium (TEMAHf) ............................................. 44
2.2.3. Bis[pentakis(ethoxy)methoxyethoxide)-tantalum]strontium.............................. 45
2.2.4. Bis[pentakis(ethoxy)dimethylaminoethoxy)-tantalum]strontium....................... 45
2.2.5. Bis(isopropoxy)bis(1-methoxy-2-methyl-2-propoxy)titanium........................... 46
2.2.6. Tertiarybutylimidtris(diethylamino)tantalum (TBTDET) .................................. 46
2.3. Structure and thickness characterization ................................................................ 47
2.3.1. Dual Beam Spectroscopy and Ellipsometry ....................................................... 47
2.3.2. X – Ray Photoelectron spectroscopy (XPS) 49
2.3.3. X – Ray diffraction and X – Ray Reflectivity .................................................... 50
2.3.4. Scanning Electron Microscopy........................................................................... 51
2.3.5. Transmission Electron Spectroscopy.................................................................. 52

32.4. Structuring of MIM capacitors ................................................................................. 52
2.4.1. Reactive Ion Etching........................................................................................... 52
2.4.2. Metallization by resistive thermal evaporation................................................... 52
2.5. Electrical characterizations ....................................................................................... 53
2.5.1. Sheet Resistance.................................................................................................. 53
2.5.2. Capacitance–Voltage measurements (C–V)............