MOVPE and characterization of GaN-based structures on alternative substrates [Elektronische Ressource] / vorgelegt von Yılmaz Dikme

Yilmaz Dikme

Sujets

• Physik

Informations

• Publié par: rheinisch-westfalischen_technischen_hochschule_-rwth-_aachen
• Publié le: 01 janvier 2006
• Nombre de lectures: 50
• Langue: Deutsch
• Poids de l'ouvrage: 7 Mo

Extrait

MOVPE and Characterization
of GaN-based Structures on
Alternative Substrates





Von der Fakultät für Elektrotechnik und Informationstechnik
der Rheinisch-Westfälischen Technischen Hochschule Aachen zur
Erlangung des akademischen Grades eines Doktors der
Ingenieurswissenschaften genehmigte Dissertation



vorgelegt von

Diplom-Ingenieur


Yılmaz Dikme

aus Erzincan, Türkei



Berichter: Prof. Dr.-Ing. M. Heuken
Prof. Dr. rer. nat. F.-J. Tegude
Prof. Dr.-Ing. R. H. Jansen



Tag der mündlichen Prüfung: 20.06.2006

Diese Dissertation ist auf den Internetseiten der Hochschulbibliothek online verfügbar.














Güven ve desteklerini hiç esirgemeyen,
ba şarıma büyük katkı sa ğlayan ve
dualarıyla hep yanımda olan
annem ve babama.

















ii
Contents

1 Introduction...........................................................................................................1
1.1 Brief history of the group of III nitrides............................................................2
1.2 Structure and motivation for this work..............................................................3
2 Fundamental material properties of group III nitrides...................................5
2.1 Crystal structure and basic material properties of group III nitrides.............5
2.2 Polarization mechanisms of group III nitrides .................................................9
3 Properties of substrates for nitride growth.................................................... 14
3.1 Silicon................................................................................................................... 15
3.2 Lithium aluminate............................................................................................... 18
3.3 Silicon carbide..................................................................................................... 20
3.4 Sapphire ............................................................................................................... 22
4 Experimental setup and characterization tools............................................. 25
5 Growth and characterization of GaN-based structures on silicon............ 28
5.1 Growth of GaN-based layer structures on silicon......................................... 28
5.1.1 GaN-buffer layers on silicon starting with low-temperature AlN...................... 28
5.1.2 Influence of Al pre-deposition on GaN-based structures on silicon
starting with high-temperature AlN ........................................................................ 34
5.2 Optical properties of AlN/GaN DBR on silicon and of GaN buffer
layers on the DBR .............................................................................................. 40
5.2.1 Growth of AlN/GaN DBR on silicon ................................................................... 41
5.2.2 Determination of growth rates and optical properties of DBR on silicon ....... 42
5.2.3 Optical properties of GaN buffer layers on DBR................................................. 44
5.3 Structural and optical properties of InGaN/GaN MQW on silicon.......... 46
5.3.1 Growth of MQW structures on silicon 47
iii Contents
5.3.2 Discussion of results of MQW on silicon with high-temperature AlN as
starting layer................................................................................................................. 48
5.3.3 Structural and optical properties of MQW on silicon with low-
temperature AlN as starting layer ............................................................................ 49
5.4 Properties of AlGaN/GaN HEMT on silicon .............................................. 56
5.4.1 Growth of HEMT on silicon ................................................................................... 56
5.4.2 Structural and electrical properties of HEMT on silicon with high-
temperature AlN as starting layer 58
5.4.3 Structural properties of HEMT on silicon with low-
temperature AlN as starting layer ............................................................................ 59
5.5 Summary and conclusion .................................................................................. 63
6 Growth and characterization of GaN-based structures on LiAlO .......... 66 2
6.1 Characterization of LiAlO substrates............................................................. 66 2
6.2 GaN-based layer growth on LiAlO with N as process gas........................ 68 2 2
6.3 with H. 74 2 2
6.3.1 GaN growth on LiAlO with H as process gas.................................................... 75 2 2
6.3.2 GaN-based LED structure growth on LiAlO with H as process gas ............. 79 2 2
6.4 Summary and conclusion .................................................................................. 82
7 GaN-based structures on SiCOI engineered substrates.............................. 84
7.1 Growth of GaN-based structures on SiCOI.................................................. 84
7.2 Structural properties of GaN buffer layers on SiCOI................................... 86
7.3 Optical properties of LED structures on SiCOI ........................................... 88
7.4 Electrical properties of HEMT structures on SiCOI.................................... 91
7.5 Summary and conclusion .................................................................................. 93
8 Summary.............................................................................................................. 94
List of figures 96
List of tables 100
iv Contents
List of abbreviations................................................................................................. 101
References.................................................................................................................. 104
Acknowledgements .................................................................................................. 123
List of publications................................................................................................... 125
Vitae............................................................................................................................ 130


v
1 Introduction


By taking a look back to the 1990s, it is obvious for everyone that information
technology (IT) has boomed and the world has started to melt together to a large
part initiated by the development of the internet. Common to this decade is also the
rapid increase in research and development on gallium nitride (GaN) and its related
alloys. No other compound semiconductor has gained so much attention and was
commercialized so fast. In comparison to the traditional semiconductors silicon (Si)
and the conventional III-V compound semiconductors, the group III nitrides offer
unique optical and electrical properties. The most popular GaN-based devices are
ultraviolet to blue laser diodes (LD) and ultraviolet to green light-emitting diodes
(LED). Various devices types, among them high electron mobility transistors
(HEMT) and solar-blind photo-detectors, are waiting for their commercialization.
The wurtzite crystal modification covers a range from 6.2 eV for aluminum nitride
(AlN) over 3.4 eV for GaN [1] down to around 0.7-1.0 eV for indium nitride (InN)
at room temperature (RT) [2,3]. Because of their wide bandgaps and strong bond
strength, GaN, AlGaN and AlN can also be used at high temperatures and in
aggressive environments. In figure 1.1, the nitride semiconductors are shown in an
image representing the spectral light. With these materials, the huge spectral range
from around 200 nm for AlN to more than 1240 nm for InN can be covered
including the whole visible spectrum. Because of these bandgaps, the group III
nitrides emerged as important materials for optoelectronics as well as for high-
temperature and high-power electronic devices. In the following sections of this
chapter, a brief history of the nitrides will be given followed by the structure of this
work.

AlN GaN InN
visible spectrum
200 200 300 300 400 400 500 500 600 600 70700 0 800 800 9900 00 11000 nm000 nm

Fig. 1.1: AlN, GaN and InN in the wavelength spectrum.





1 1 Introduction
1.1 Brief history of the group of III nitrides

In this section, some important historical research activities will be presented. In
table 1.1, all important dates of the evolution of the group III nitrides are listed. The
research started in 1969 with the growth of GaN on sapphire by hydride vapor phase
epitaxy (HVPE) [4]. In 1971, the first metal-insulator-semiconductor (MIS) LED [5]
was demonstrated but until 1989, only a few publications and improvements of GaN
have been published. Since 1992 up to now, the research and development activities
in the field of the group III nitrides rapidly increased. From th