scholarly journals Properties and Effects of Hydrogen in GaN

2000 ◽  
Vol 5 (S1) ◽  
pp. 540-550 ◽  
Author(s):  
S.J. Pearton ◽  
H. Cho ◽  
F. Ren ◽  
J.-I. Chyi ◽  
J. Han ◽  
...  
Keyword(s):  
Heterojunction Bipolar Transistors ◽  
Bipolar Transistors ◽  
Residual Hydrogen ◽  
Diffusion Characteristics ◽  
Significant Difference ◽  
Device Structures ◽  
The Status ◽  
The Difference ◽  
Thermal Stability Of ◽  
Mg Doped

The status of understanding of the behavior of hydrogen in GaN and related materials is reviewed. In particular, we discuss the amount of residual hydrogen in MOCVD-grown device structures such as heterojunction bipolar transistors, thyristors and p-i-n diodes intended for high power, high temperature applications. In these structures, the residual hydrogen originating from the growth precursors decorates Mg-doped layers and AlGaN/GaN interfaces. There is a significant difference in the diffusion characteristics and thermal stability of implanted hydrogen between n- and p-GaN, due to the stronger affinity of hydrogen to pair with acceptor dopants and possibly to the difference in H2 formation probability.

Properties and Effects of Hydrogen in GaN

1999 ◽  
Vol 595 ◽  
Author(s):  
S.J. Pearton ◽  
H. Cho ◽  
F. Ren ◽  
J.-I. Chyi ◽  
J. Han ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Heterojunction Bipolar Transistors ◽  
Bipolar Transistors ◽  
Residual Hydrogen ◽  
Diffusion Characteristics ◽  
Significant Difference ◽  
Device Structures ◽  
The Status ◽  
The Difference ◽  
Thermal Stability Of

AbstractThe status of understanding of the behavior of hydrogen in GaN and related materials is reviewed. In particular, we discuss the amount of residual hydrogen in MOCVD-grown device structures such as heterojunction bipolar transistors, thyristors and p-i-n diodes intended for high power, high temperature applications. In these structures, the residual hydrogen originating from the growth precursors decorates Mgdoped layers and AlGaN/GaN interfaces. There is a significant difference in the diffusion characteristics and thermal stability of implanted hydrogen between n- and p-GaN, due to the stronger affinity of hydrogen to pair with acceptor dopants and possibly to the difference in H2 formation probability.

Novel Multi-Finger Power HBTs with Non-Uniform Segmented Emitter for Thermal Stability Enhancement

2012 ◽  
Vol 229-231 ◽  
pp. 832-836 ◽  
Author(s):  
D.Y. Jin ◽  
D. Lu ◽  
W.R. Zhang ◽  
Q. Fu ◽  
Y.J. Zhang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Heterojunction Bipolar Transistors ◽  
Heat Dissipation ◽  
Current Density Distribution ◽  
Bipolar Transistors ◽  
Electrical Model ◽  
Collector Current ◽  
The Difference ◽  
Stability Enhancement ◽  
Thermal Stability Of

With the aid of a two-dimensional thermal-electrical model, the thermal stability of multi-finger power heterojunction bipolar transistors (HBTs) with uniform segmented emitter, and non-uniform segmented emitter are studied. It shows that both of them could lower the peak temperature and improve the non-uniformity of the collector current density distribution, and thus improve the thermal stability, compared with an HBT which has traditional non-segmented emitter structure. At the same time, the improvement capability of thermal stability for HBT with non-uniform segmented emitter is superior to that of HBT with uniform segmented emitter, ascribing to selectively divide the emitter fingers into various segments according to the difference of heat dissipation capability in emitter fingers. Furthermore, the improvement capability of thermal stability for HBT with non-uniform segmented emitter is enhanced exponentially as segment spacing increases. However, for HBT with uniform segmented emitter, the ability is less sensitive to the increasing of the segment spacing as it exceeds 6μm. Therefore, the technique of non-uniform segmented emitter is a better method for enhancing the thermal stability of power HBTs.

Microstructural Characterization of High-Pressure Oxidized Si1-x Gex /Si Heterolayers

1992 ◽  
Vol 280 ◽  
Author(s):  
N. David Theodore ◽  
Gordon Tam
Keyword(s):  
Heterojunction Bipolar Transistors ◽  
Atmospheric Pressure ◽  
High Pressures ◽  
Microstructural Characterization ◽  
Bipolar Transistors ◽  
Pure Silicon ◽  
Device Structures ◽  
Microstructural Behavior ◽  
Very High

ABSTRACTSiGe alloys have recently been of interest for fabrication of heterojunction bipolar transistors using pre-existing or modified silicon-processing technology. These devices are faster than devices using pure silicon. Because of the interest in developing SiGe device structures, various elements of processing relevant to fabrication of the devices are being investigated. One such element has been the use of thermal oxidation for isolation of SiGe devices. Utilization of the technique requires an understanding of oxidation behavior of SiGe layers under a variety of oxidation conditions. Past studies in the literature have investigated the oxidation of SiGe at atmospheric pressure or at very high pressures (∼650–1300 atmospheres). The present study investigates the wet-oxidation of SiGe structures at intermediate pressures (∼25 atmospheres) and temperatures (∼750°C). Unlike atmospheric oxidation, most of the Ge (from SiGe) remains in the oxidized silicon (SiO2) in the form of GeO2. Occasional segregation of Ge to the oxidizing interface is noted. The microstructural behavior of partially and entirely oxidized structures is presented.

ION IMPLANTATION IN III–V SEMICONDUCTOR TECHNOLOGY

1993 ◽  
Vol 07 (28) ◽  
pp. 4687-4761 ◽  
Author(s):  
S.J. PEARTON
Keyword(s):  
Ion Implantation ◽  
Heterojunction Bipolar Transistors ◽  
Semiconductor Device ◽  
Bipolar Transistors ◽  
Semiconductor Technology ◽  
Selective Area ◽  
Device Structures ◽  
Doping Profiles ◽  
Multi Quantum Well ◽  
Device Technology

A review is given of the applications of ion implantation in III–V compound semiconductor device technology, beginning with the fundamentals of ion stopping in these materials and describing the use of implantation for both doping and isolation. There is increasing interest in the use of MeV implantation to create unique doping profiles or for the isolation of thick device structures such as heterojunction bipolar transistors or multi quantum well lasers, and we give details of these areas and the metal masking layers necessary for selective area processing. Finally, examples are given of the use of implantation in a variety of III–V devices.

The Challenge of GaAs Heterojunction Bipolar Transistor Integrated Circuit Technology.

1988 ◽  
Vol 144 ◽  
Author(s):  
Han-Tzong Yuan
Keyword(s):  
Integrated Circuits ◽  
Heterojunction Bipolar Transistors ◽  
Integrated Circuit ◽  
Large Scale ◽  
Ohmic Contacts ◽  
Bipolar Transistors ◽  
Bipolar Transistor ◽  
Heterojunction Bipolar Transistor ◽  
The Status ◽  
Impurity Doping

ABSTRACTThe status and progress of AlGaAs/GaAs heterojunction bipolar transistor integrated circuits are reviewed. The challenge of fabricating large-scale integrated circuits using heterojunction bipolar transistors is discussed. Specifically, the issues related to low defect epitaxial materials, localized impurity doping techniques, simple and reliable ohmic contacts, and multilevel interconnects are examined.

Fabrication, Performance, and Reliability of InP-Based HBTs

1993 ◽  
Vol 300 ◽  
Author(s):  
William E. Stanchina ◽  
Robert A. Metzger ◽  
Joseph F. Jensen ◽  
Madjid Hafizi ◽  
David B. Rensch
Keyword(s):  
Indium Phosphide ◽  
Indium Arsenide ◽  
Heterojunction Bipolar Transistors ◽  
Integrated Circuit ◽  
Material Properties ◽  
Bipolar Transistors ◽  
Gallium Indium Arsenide ◽  
The Past ◽  
The Status ◽  
Performance Results

ABSTRACTOver the past 10 years, heterojunction bipolar transistors (HBTs) have progressed to where integrated circuit (IC) products are being sold and foundry services are being commercially offered utilizing gallium arsenide (GaAs) based technology. We will discuss, here, an alternative HBT technology based on indium phosphide (InP). While this technology is less mature than its GaAs counterpart, it offers several attractive benefits in comparison with GaAs. These benefits are provided through several key material properties of InP and ternary compound semiconductors, eg. gallium indium arsenide (GaInAs), grown on the InP. We review the status of this npn HBT technology and present performance results which illustrate the benefits of the technology with respect to electronic applications. Finally, we present measured reliability data for this technology which shows outstanding projected lifetimes.

scholarly journals Value of Transthoracic Echocardiography in the Prediction of Post-spinal Anesthesia Hypotension

2020 ◽  
Author(s):  
Ferdi Gülaştı ◽  
Sevil Gülaştı ◽  
İbrahim Girgin ◽  
Sinem Sarı
Keyword(s):  
Spinal Anesthesia ◽  
Transthoracic Echocardiography ◽  
Physical Status ◽  
Global Function ◽  
Inguinal Hernia Operation ◽  
Significant Difference ◽  
The Status ◽  
Hernia Operation ◽  
The Difference ◽  
Diastolic Functions

INTRODUCTION: Spinal Anesthesia (SA) can lead to hypotension due to sympathic denervation, which causes a reduction in venous return to the heart as a result of peripheral vasodilation and redistribution of intravascular blood. Transthoracic Echocardiography (TTE) is a noninvasive and easy-to-use method to visualize cardiac reserve and functions. We aimed to evaluate whether parameters attained via transthoracic echocardiography are predictive of development of post-SA hypotension. METHODS: Forty-two patients between the ages of 18 and 80, who would undergo inguinal hernia operation under SA, with ASA physical status I-II and had no clinically recognized cardiovascular disease, were included in the study. TTE was performed for each patient 30 minutes before the operation, and measurements were recorded along with the intraoperative hemodynamic parameters. RESULTS: There was a statistically significant difference between the medians of left ventricle end-diastolic diameter (LVEDD) (cm) according to the status of post-SA hypotension (p=0.003).Accordingly, median LVEDD of patients who did not develop hypotension was significantly larger compared with that of those who had hypotension. Similarly, a statistically significant difference emerged between the medians of right ventricular (RV) tricuspid annular plane systolic excursion (TAPSE) (cm) showing RV global function according to the status of post-SA hypotension (p=0.001). Accordingly, patients who did not have hypotension had a larger RV-TAPSE median compared with that of those who had hypotension. The difference between the medians of RV isovolumetric relaxation time (RV-IVRT), which is one of the indicators of RV diastolic functions was again statistically significant according to the status of post-SA hypotension (p=0.025). DISCUSSION AND CONCLUSION: TAPSE, RV-IVRT and LVEDD measured via preoperative TTE, can be significant parameters to predict the development of post-SA hypotension.

Characteristics of μc-Si:H for Si Heterojunction Bipolar Transistors

1989 ◽  
Vol 164 ◽  
Author(s):  
H. Fujioka ◽  
M. Ito ◽  
K. Takasaki
Keyword(s):  
Thermal Stability ◽  
Hydrogen Concentration ◽  
Heterojunction Bipolar Transistors ◽  
Bipolar Transistors ◽  
Carbon Doping ◽  
Thermally Stable ◽  
Fluorine Doping ◽  
Hydrogen Atoms ◽  
Thermal Stability Of ◽  
Crystalline Growth

AbstractTo improve the thermal stability of the Si heterojunction bipolar transistors (HBTs), we studied the effect of carbon and fluorine doping on μc-Si:H characteristics. We found that carbon doping suppresses crystalline growth and increases the hydrogen concentration in the film, and that fluorine atoms are more thermally stable than hydrogen atoms. We confirmed that carbon or fluorine doping is promising for use with the μc-Si:H HBT.

Comparison of Mesa- Etched and Ion- Implanted GexSi1-x Heterojunction Bipolar Transistors

1992 ◽  
Vol 262 ◽  
Author(s):  
D. W. Greve ◽  
M. Racanelli
Keyword(s):  
Heterojunction Bipolar Transistors ◽  
Bipolar Transistors ◽  
Strained Layer ◽  
Device Structures ◽  
Germanium Silicon ◽  
Ion Implanted

ABSTRACTWe report a comparison of the characteristics of germanium- silicon base heterojunction bipolar transistors fabricated using mesa- etched and ion- implanted processes. The base currents of both device structures are dominated by peripheral currents associated with the plasma- SiO2 covered junction edge. After an implant damage anneal at 800 or 900 C, the ion- implanted process exhibited the lowest base currents. There was no evidence of strained layer relaxation even for the 900 C anneal.

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