n-AlGaAs/p-GaAs/n-GaN HETEROJUNCTION BIPOLAR TRANSISTOR: THE FIRST TRANSISTOR FORMED VIA WAFER FUSION

2004 ◽  
Vol 14 (01) ◽  
pp. 265-284 ◽  
Author(s):  
SARAH ESTRADA ◽  
EVELYN HU ◽  
UMESH MISHRA
Keyword(s):  
Structural Information ◽  
Bipolar Transistor ◽  
Heterojunction Bipolar Transistor ◽  
Electrical Performance ◽  
Chemical Information ◽  
Wafer Fusion ◽  
Transmission Electron ◽  
Current Voltage

We discuss the first reported device characteristics of a wafer-fused heterojunction bipolar transistor (HBT), demonstrating the potential of wafer fusion for the production of electrically active heterostructures between lattice-mismatched materials. n-GaAs / n-GaN ("n-n") and p-GaAs / n-GaN ("p-n") heterojunctions were successfully fused and processed into current-voltage (I-V) test structures. The fusion and characterization of these simple structures provided insight for the fabrication of the more complicated HBT structures. Initial HBT devices performed with promising dc common-emitter I-V characteristics and Gummel plots. n-n, p-n, and HBT electrical performance was correlated with systematically varied fusion conditions, and with the quality of the fused interface, given both chemical information provided by secondary ion mass spectroscopy (SIMS) and structural information from high resolution transmission electron microscopy (HRTEM) analysis.

The First Wafer-fused AlGaAs-GaAs-GaN Heterojunction Bipolar Transistor

2002 ◽  
Vol 743 ◽  
Author(s):  
Sarah Estrada ◽  
Andreas Stonas ◽  
Andrew Huntington ◽  
Huili Xing ◽  
Larry Coldren ◽  
...  
Keyword(s):  
High Mobility ◽  
Bipolar Transistor ◽  
Heterojunction Bipolar Transistor ◽  
Current Gain ◽  
Fusion Temperature ◽  
Device Structure ◽  
Wafer Fusion ◽  
Current Voltage ◽  
Diffusion Effects ◽  
Current Voltage Characteristics

ABSTRACTWe describe the use of wafer fusion to form a heterojunction bipolar transistor (HBT), with an AlGaAs-GaAs emitter-base fused to a GaN collector. In this way, we hope to make use of both the high breakdown voltage of the GaN and the high mobility of the technologically more mature GaAs-based materials. This paper reports the first dc device characteristics of a wafer-fused transistor, and demonstrates the potential of wafer fusion for forming electronically active, lattice-mismatched heterojunctions. Devices utilized a thick base (0.15um) and exhibited limited common-emitter current gain (0.2–0.5) at an output current density of ∼100A/cm2. Devices were operated to VCE greater than 20V, with a low VCE offset (1V). Improvements in both device structure and wafer fusion conditions should provide further improvements in HBT performance. The HBT was wafer-fused at 750°C for one hour. Current-voltage characteristics of wafer-fused p-GaAs/n-GaN diodes suggest that the fusion temperature could be reduced to 500°C. Such a reduction in process temperature should mitigate detrimental diffusion effects in future HBTs.

Structural and Electrical Characterization of Si-Implanted TiN as a Diffusion Barrier for Cu Metallization

1995 ◽  
Vol 391 ◽  
Author(s):  
W.F. Mcarthur ◽  
K.M. Ring ◽  
K.L. Kavanagh
Keyword(s):  
Leakage Current ◽  
Diffusion Barrier ◽  
Depth Profiling ◽  
Electrical Characterization ◽  
Implantation Dose ◽  
Cu Metallization ◽  
Reverse Leakage Current ◽  
Transmission Electron ◽  
Current Voltage

AbstractThe feasibility of Si-implanted TiN as a diffusion barrier between Cu and Si was investigated. Barrier effectiveness was evaluated via reverse leakage current of Cu/TixSiyNz/Si diodes as a function of post-deposition annealing temperature and time, and was found to depend heavily on the film composition and microstructure. TiN implanted with Si28, l0keV, 5xl016ions/cm2 formed an amorphous ternary TixSiyNz layer whose performance as a barrier to Cu diffusion exceeded that of unimplanted, polycrystalline TiN. Results from current-voltage, transmission electron microscopy (TEM), and Auger depth profiling measurements will be presented. The relationship between Si-implantation dose, TixSiyNz structure and reverse leakage current of Cu/TixSiyNz/Si diodes will be discussed, along with implications as to the suitability of these structures in Cu metallization.

Characterization of JEOL 3000f TEM Equipped for Electron Holography

2000 ◽  
Vol 6 (S2) ◽  
pp. 228-229
Author(s):  
M. A. Schofield ◽  
Y. Zhu
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Design Of Experiment ◽  
Electron Holography ◽  
Fringe Spacing ◽  
Interference Fringes ◽  
Transmission Electron ◽  
Careful Design

Quantitative off-axis electron holography in a transmission electron microscope (TEM) requires careful design of experiment specific to instrumental characteristics. For example, the spatial resolution desired for a particular holography experiment imposes requirements on the spacing of the interference fringes to be recorded. This fringe spacing depends upon the geometric configuration of the TEM/electron biprism system, which is experimentally fixed, but also upon the voltage applied to the biprism wire of the holography unit, which is experimentally adjustable. Hence, knowledge of the holographic interference fringe spacing as a function of applied voltage to the electron biprism is essential to the design of a specific holography experiment. Furthermore, additional instrumental parameters, such as the coherence and virtual size of the electron source, for example, affect the quality of recorded holograms through their effect on the contrast of the holographic fringes.

Polarized-photoreflectance characterization of an InGaP/InGaAsN/GaAsNpNdouble-heterojunction bipolar transistor structure

2001 ◽  
Vol 90 (9) ◽  
pp. 4565-4569 ◽  
Author(s):  
C. J. Lin ◽  
Y. S. Huang ◽  
N. Y. Li ◽  
P. W. Li ◽  
K. K. Tiong
Keyword(s):  
Bipolar Transistor ◽  
Heterojunction Bipolar Transistor ◽  
Transistor Structure

A Reactor for “Ex-Situ” TEM Catalyst Characterization

1999 ◽  
Vol 5 (S2) ◽  
pp. 926-927 ◽  
Author(s):  
C.E. Kliewer ◽  
M.M. Disko ◽  
S.L Soled ◽  
G.J. DeMartin
Keyword(s):  
Catalytic Properties ◽  
Structural Information ◽  
High Vacuum ◽  
Chemical Characterization ◽  
Ex Situ ◽  
Catalyst Characterization ◽  
Initial Development ◽  
Transmission Electron ◽  
Pressure Variable

The microstructural and chemical characterization of catalysts is not only integral to their initial development but also to understanding and controlling their behavior over time. To better elucidate the morphology of these materials and relate physical properties to catalytic properties (e.g., activity, selectivity, etc.), “ex-situ” methods for studying catalysts under reactive conditions have been developed.Because conventional transmission electron microscopy (CTEM) is conducted under high vacuum conditions, it is difficult to replicate the exact chemical environment of a catalyst (e.g., high pressure, variable gas mixtures, etc) within the TEM. Consequently, most analyses focus on comparing “fresh” and “spent” materials. In general, this methodology provides useful structural information albeit with limitations associated with the comparison of dissimilar regions and the effects of sampling inhomogenieties.

Characterization of GaAs/Ga1−xAlxAs heterojunction bipolar transistor structures using photoreflectance

1990 ◽  
Vol 56 (13) ◽  
pp. 1278-1280 ◽  
Author(s):  
X. Yin ◽  
Fred H. Pollak ◽  
L. Pawlowicz ◽  
T. O’Neill ◽  
M. Hafizi
Keyword(s):  
Bipolar Transistor ◽  
Heterojunction Bipolar Transistor

Lattice-Fringe Fingerprinting: Structural identification of nanocrystals by HRTEM

2007 ◽  
Vol 1026 ◽  
Author(s):  
Moeck Peter ◽  
Ruben Bjorge
Keyword(s):  
Structural Information ◽  
Reciprocal Lattice ◽  
Chemical Information ◽  
Fourier Synthesis ◽  
Transmission Electron ◽  
Structure Factors ◽  
Lattice Geometry ◽  
Group A ◽  
Experimental Side ◽  
Novel Method

AbstractA novel method for the structurally identification of a nanocrystal from a single high resolution (HR) transmission electron microscopy (TEM) micrograph is described. Components of this method are demonstrated on both experimental and simulated HRTEM images. On the experimental side, the structural information that can be extracted from a HRTEM image is the projected reciprocal lattice geometry, the plane symmetry group, a few structure factor amplitudes and phases, and an outline of the projected atomic structure to the limited resolution of the HRTEM (via a Fourier synthesis of the structure factors). Searching for this information in a comprehensive database and matching it with high figures of merit to that of candidate structures should allow for highly discriminatory identifications of nanocrystals, even without additional chemical information as obtainable in analytical TEMs.

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