Author: Patrick Hofmann
Publisher: BoD – Books on Demand
ISBN: 3752884924
Category : Science
Languages : en
Pages : 166
Book Description
This dissertation employs doping to investigate basic gallium nitride (GaN) crystal properties and to solve challenges of the hydride vapour phase epitaxy (HVPE) growth process. Whereas the first chapter is a short introduction to the history of the GaN single crystal growth, the 2nd chapter introduces to current crystal growth techniques, discusses properties of the GaN material system and the resulting influence on the applicable crystal growth techniques. HVPE, as a vapour phase epitaxy crystal growth method will be explained in greater detail, with focus on the used vertical reactor and its capabilities for doping. The 3rd chapter then focusses on point defects in GaN, specifically on intentionally introduced extrinsic point defects used for doping purposes, i.e. to achieve p-type, n-type or semi-insulating behaviour. Different dopants will be reviewed before the diffusion of point defects in a solid will be discussed. The in-situ introduction of iron, manganese, and carbon during crystal growth is employed in chapter 4 to compensate the unintentional doping (UID) of the GaN crystals, and therefore to achieve truly semi-insulating behaviour of the HVPE GaN. However the focus of this chapter lies on the characterisation of the pyroelectric coefficient (p), as semi-insulating properties are a necessary requirement for the applied Sharp-Garn measurement method. The creation of tensile stress due to in-situ silicon doping during GaN crystal growth is the topic of the 5th chapter. The tensile stress generation effect will be reproduced and the strain inside the crystal will be monitored ex-situ employing Raman spectroscopy. The n-type doping is achieved by using a vapour phase doping line and a process is developed to hinder the tensile strain generation effect. The 6th chapter concentrates on the delivery of the doping precursor via a solid state doping line, a newly developed doping method. Similar to chapter 5, the doping line is characterised carefully before the germanium doping is employed to the GaN growth. The focus lies on the homogeneity of the germanium doping and it is compared compared to the silicon doping and the vapour phase doping line. Benefits and drawbacks are discussed in conjunction with the obtained results. The germanium doping via solid state doping line is applied to the HVPE GaN growth process to measure accurately growth process related properties unique to the applied set of GaN growth parameters.
Hydride vapour phase epitaxy growth, crystal properties and dopant incorporation in gallium nitride
Author: Patrick Hofmann
Publisher: BoD – Books on Demand
ISBN: 3752884924
Category : Science
Languages : en
Pages : 166
Book Description
This dissertation employs doping to investigate basic gallium nitride (GaN) crystal properties and to solve challenges of the hydride vapour phase epitaxy (HVPE) growth process. Whereas the first chapter is a short introduction to the history of the GaN single crystal growth, the 2nd chapter introduces to current crystal growth techniques, discusses properties of the GaN material system and the resulting influence on the applicable crystal growth techniques. HVPE, as a vapour phase epitaxy crystal growth method will be explained in greater detail, with focus on the used vertical reactor and its capabilities for doping. The 3rd chapter then focusses on point defects in GaN, specifically on intentionally introduced extrinsic point defects used for doping purposes, i.e. to achieve p-type, n-type or semi-insulating behaviour. Different dopants will be reviewed before the diffusion of point defects in a solid will be discussed. The in-situ introduction of iron, manganese, and carbon during crystal growth is employed in chapter 4 to compensate the unintentional doping (UID) of the GaN crystals, and therefore to achieve truly semi-insulating behaviour of the HVPE GaN. However the focus of this chapter lies on the characterisation of the pyroelectric coefficient (p), as semi-insulating properties are a necessary requirement for the applied Sharp-Garn measurement method. The creation of tensile stress due to in-situ silicon doping during GaN crystal growth is the topic of the 5th chapter. The tensile stress generation effect will be reproduced and the strain inside the crystal will be monitored ex-situ employing Raman spectroscopy. The n-type doping is achieved by using a vapour phase doping line and a process is developed to hinder the tensile strain generation effect. The 6th chapter concentrates on the delivery of the doping precursor via a solid state doping line, a newly developed doping method. Similar to chapter 5, the doping line is characterised carefully before the germanium doping is employed to the GaN growth. The focus lies on the homogeneity of the germanium doping and it is compared compared to the silicon doping and the vapour phase doping line. Benefits and drawbacks are discussed in conjunction with the obtained results. The germanium doping via solid state doping line is applied to the HVPE GaN growth process to measure accurately growth process related properties unique to the applied set of GaN growth parameters.
Publisher: BoD – Books on Demand
ISBN: 3752884924
Category : Science
Languages : en
Pages : 166
Book Description
This dissertation employs doping to investigate basic gallium nitride (GaN) crystal properties and to solve challenges of the hydride vapour phase epitaxy (HVPE) growth process. Whereas the first chapter is a short introduction to the history of the GaN single crystal growth, the 2nd chapter introduces to current crystal growth techniques, discusses properties of the GaN material system and the resulting influence on the applicable crystal growth techniques. HVPE, as a vapour phase epitaxy crystal growth method will be explained in greater detail, with focus on the used vertical reactor and its capabilities for doping. The 3rd chapter then focusses on point defects in GaN, specifically on intentionally introduced extrinsic point defects used for doping purposes, i.e. to achieve p-type, n-type or semi-insulating behaviour. Different dopants will be reviewed before the diffusion of point defects in a solid will be discussed. The in-situ introduction of iron, manganese, and carbon during crystal growth is employed in chapter 4 to compensate the unintentional doping (UID) of the GaN crystals, and therefore to achieve truly semi-insulating behaviour of the HVPE GaN. However the focus of this chapter lies on the characterisation of the pyroelectric coefficient (p), as semi-insulating properties are a necessary requirement for the applied Sharp-Garn measurement method. The creation of tensile stress due to in-situ silicon doping during GaN crystal growth is the topic of the 5th chapter. The tensile stress generation effect will be reproduced and the strain inside the crystal will be monitored ex-situ employing Raman spectroscopy. The n-type doping is achieved by using a vapour phase doping line and a process is developed to hinder the tensile strain generation effect. The 6th chapter concentrates on the delivery of the doping precursor via a solid state doping line, a newly developed doping method. Similar to chapter 5, the doping line is characterised carefully before the germanium doping is employed to the GaN growth. The focus lies on the homogeneity of the germanium doping and it is compared compared to the silicon doping and the vapour phase doping line. Benefits and drawbacks are discussed in conjunction with the obtained results. The germanium doping via solid state doping line is applied to the HVPE GaN growth process to measure accurately growth process related properties unique to the applied set of GaN growth parameters.
Vertical Gallium Nitride PowerDevices: Fabrication and Characterisation
Author: Rico Hentschel
Publisher: BoD – Books on Demand
ISBN: 3752641762
Category : Science
Languages : en
Pages : 156
Book Description
Efficient power conversion is essential to face the continuously increasing energy consumption of our society. GaN based vertical power field effect transistors provide excellent performance figures for power-conversion switches, due to their capability of handling high voltages and current densities with very low area consumption. This work focuses on a vertical trench gate metal oxide semiconductor field effect transistor (MOSFET) with conceptional advantages in a device fabrication preceded GaN epitaxy and enhancement mode characteristics. The functional layer stack comprises from the bottom an n+/n--drift/p-body/n+-source GaN layer sequence. Special attention is paid to the Mg doping of the p-GaN body layer, which is a complex topic by itself. Hydrogen passivation of magnesium plays an essential role, since only the active (hydrogen-free) Mg concentration determines the threshold voltage of the MOSFET and the blocking capability of the body diode. Fabrication specific challenges of the concept are related to the complex integration, formation of ohmic contacts to the functional layers, the specific implementation and processing scheme of the gate trench module and the lateral edge termination. The maximum electric field, which was achieved in the pn- junction of the body diode of the MOSFET is estimated to be around 2.1 MV/cm. From double-sweep transfer measurements with relatively small hysteresis, steep subthreshold slope and a threshold voltage of 3 - 4 V a reasonably good Al2O3/GaN interface quality is indicated. In the conductive state a channel mobility of around 80 - 100 cm2/Vs is estimated. This value is comparable to device with additional overgrowth of the channel. Further enhancement of the OFF-state and ON-state characteristics is expected for optimization of the device termination and the high-k/GaN interface of the vertical trench gate, respectively. From the obtained results and dependencies key figures of an area efficient and competitive device design with thick drift layer is extrapolated. Finally, an outlook is given and advancement possibilities as well as technological limits are discussed.
Publisher: BoD – Books on Demand
ISBN: 3752641762
Category : Science
Languages : en
Pages : 156
Book Description
Efficient power conversion is essential to face the continuously increasing energy consumption of our society. GaN based vertical power field effect transistors provide excellent performance figures for power-conversion switches, due to their capability of handling high voltages and current densities with very low area consumption. This work focuses on a vertical trench gate metal oxide semiconductor field effect transistor (MOSFET) with conceptional advantages in a device fabrication preceded GaN epitaxy and enhancement mode characteristics. The functional layer stack comprises from the bottom an n+/n--drift/p-body/n+-source GaN layer sequence. Special attention is paid to the Mg doping of the p-GaN body layer, which is a complex topic by itself. Hydrogen passivation of magnesium plays an essential role, since only the active (hydrogen-free) Mg concentration determines the threshold voltage of the MOSFET and the blocking capability of the body diode. Fabrication specific challenges of the concept are related to the complex integration, formation of ohmic contacts to the functional layers, the specific implementation and processing scheme of the gate trench module and the lateral edge termination. The maximum electric field, which was achieved in the pn- junction of the body diode of the MOSFET is estimated to be around 2.1 MV/cm. From double-sweep transfer measurements with relatively small hysteresis, steep subthreshold slope and a threshold voltage of 3 - 4 V a reasonably good Al2O3/GaN interface quality is indicated. In the conductive state a channel mobility of around 80 - 100 cm2/Vs is estimated. This value is comparable to device with additional overgrowth of the channel. Further enhancement of the OFF-state and ON-state characteristics is expected for optimization of the device termination and the high-k/GaN interface of the vertical trench gate, respectively. From the obtained results and dependencies key figures of an area efficient and competitive device design with thick drift layer is extrapolated. Finally, an outlook is given and advancement possibilities as well as technological limits are discussed.
Nitrides and Related Wide Band Gap Materials
Author: A. Hangleiter
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 440
Book Description
The Symposium on 'Nitrides and related wide band gap materials' at the 1998 Spring Meeting of the European Materials Research Society (E-MRS) in Strasbourg, France, was the third Symposium of its kind at an E-MRS meeting. Beginning in 1996, these Symposia enjoyed a steadily increasing popularity among European and international nitride researchers. Contributions covered the areas of hetero-epitaxy, bulk growth, structural, electrical and optical characterisation and device fabrication. Researchers from about 20 different countries presented their work at this symposium. Naturally, most papers were from within Europe (Germany, France, Russia and the United Kingdom) but there was also a remarkable number of contributions from overseas (USA, Japan and Korea.) For about 5 years now, semiconducting group-III nitrides have attracted an enormous level of research activity all over the world. Essentially this was triggered by the breakthroughs achieved by Shuji Nakamura and his group in Japan, who succeeded in making highly efficient blue, green and yellow light emitting diodes as well as violet laser diodes based on A1GaInN. Since then, intensive research related to material growth, device development, as well as to the fundamental properties of these materials is being carried out. The outstanding contribution of Shuji Nakamura to this field was underlined by his plenary lecture during this E-MRS meeting. He presented his most recent progress towards amber LED's and long-lived violet laser diodes.
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 440
Book Description
The Symposium on 'Nitrides and related wide band gap materials' at the 1998 Spring Meeting of the European Materials Research Society (E-MRS) in Strasbourg, France, was the third Symposium of its kind at an E-MRS meeting. Beginning in 1996, these Symposia enjoyed a steadily increasing popularity among European and international nitride researchers. Contributions covered the areas of hetero-epitaxy, bulk growth, structural, electrical and optical characterisation and device fabrication. Researchers from about 20 different countries presented their work at this symposium. Naturally, most papers were from within Europe (Germany, France, Russia and the United Kingdom) but there was also a remarkable number of contributions from overseas (USA, Japan and Korea.) For about 5 years now, semiconducting group-III nitrides have attracted an enormous level of research activity all over the world. Essentially this was triggered by the breakthroughs achieved by Shuji Nakamura and his group in Japan, who succeeded in making highly efficient blue, green and yellow light emitting diodes as well as violet laser diodes based on A1GaInN. Since then, intensive research related to material growth, device development, as well as to the fundamental properties of these materials is being carried out. The outstanding contribution of Shuji Nakamura to this field was underlined by his plenary lecture during this E-MRS meeting. He presented his most recent progress towards amber LED's and long-lived violet laser diodes.
Chemical Vapor Deposition: 1960-1980
Author: Donald T. Hawkins
Publisher: Springer
ISBN:
Category : Reference
Languages : en
Pages : 762
Book Description
Publisher: Springer
ISBN:
Category : Reference
Languages : en
Pages : 762
Book Description
Chemical Abstracts
Ceramic Abstracts
Crystal Growth Bibliography
Author: Anne M. Keesee
Publisher:
ISBN:
Category : Crystal growth
Languages : en
Pages : 584
Book Description
Publisher:
ISBN:
Category : Crystal growth
Languages : en
Pages : 584
Book Description
Organometallic Vapor-Phase Epitaxy
Author: Gerald B. Stringfellow
Publisher: Elsevier
ISBN: 0323139175
Category : Science
Languages : en
Pages : 417
Book Description
Here is one of the first single-author treatments of organometallic vapor-phase epitaxy (OMVPE)--a leading technique for the fabrication of semiconductor materials and devices. Also included are metal-organic molecular-beam epitaxy (MOMBE) and chemical-beam epitaxy (CBE) ultra-high-vacuum deposition techniques using organometallic source molecules. Of interest to researchers, students, and people in the semiconductor industry, this book provides a basic foundation for understanding the technique and the application of OMVPE for the growth of both III-V and II-VI semiconductor materials and the special structures required for device applications. In addition, a comprehensive summary detailing the OMVPE results observed to date in a wide range of III-V and II-VI semiconductors is provided. This includes a comparison of results obtained through the use of other epitaxial techniques such as molecular beam epitaxy (MBE), liquid-phase epitaxy (LPE), and vapor phase epitaxy using halide transport.
Publisher: Elsevier
ISBN: 0323139175
Category : Science
Languages : en
Pages : 417
Book Description
Here is one of the first single-author treatments of organometallic vapor-phase epitaxy (OMVPE)--a leading technique for the fabrication of semiconductor materials and devices. Also included are metal-organic molecular-beam epitaxy (MOMBE) and chemical-beam epitaxy (CBE) ultra-high-vacuum deposition techniques using organometallic source molecules. Of interest to researchers, students, and people in the semiconductor industry, this book provides a basic foundation for understanding the technique and the application of OMVPE for the growth of both III-V and II-VI semiconductor materials and the special structures required for device applications. In addition, a comprehensive summary detailing the OMVPE results observed to date in a wide range of III-V and II-VI semiconductors is provided. This includes a comparison of results obtained through the use of other epitaxial techniques such as molecular beam epitaxy (MBE), liquid-phase epitaxy (LPE), and vapor phase epitaxy using halide transport.
Gallium Nitride and Related Materials
Author:
Publisher:
ISBN:
Category : Electroluminescent devices
Languages : en
Pages : 538
Book Description
Publisher:
ISBN:
Category : Electroluminescent devices
Languages : en
Pages : 538
Book Description
Gallium Nitride and Related Materials II: Volume 468
Author: C. R. Abernathy
Publisher: Materials Research Society
ISBN: 9781558993723
Category : Technology & Engineering
Languages : en
Pages : 534
Book Description
This book from MRS dedicated to III-Nitrides, focuses on developments in AlN, GaN, InN and their alloys that are now finding application in short-wavelength lasers (~400nm, cw at room temperature) and high-power electronics (2.8W/mm at GHz). Experts from fields including crystal growth, condensed matter theory, source chemistry, device processing and device design come together in the volume to address issues of both scientific and technological relevance. And while much of the book reports on advances in material preparation and the understanding of defect issues, similar advances in material and device processing are also reported. Topics include: growth and doping; substrates and substrate effects; characterization; processing and device performance and design.
Publisher: Materials Research Society
ISBN: 9781558993723
Category : Technology & Engineering
Languages : en
Pages : 534
Book Description
This book from MRS dedicated to III-Nitrides, focuses on developments in AlN, GaN, InN and their alloys that are now finding application in short-wavelength lasers (~400nm, cw at room temperature) and high-power electronics (2.8W/mm at GHz). Experts from fields including crystal growth, condensed matter theory, source chemistry, device processing and device design come together in the volume to address issues of both scientific and technological relevance. And while much of the book reports on advances in material preparation and the understanding of defect issues, similar advances in material and device processing are also reported. Topics include: growth and doping; substrates and substrate effects; characterization; processing and device performance and design.