Correlation between leakage current density and threading dislocation density in SiGe p-i-n diodes grown on relaxed graded buffer layers

2001 ◽  
Vol 78 (4) ◽  
pp. 541-543 ◽  
Author(s):  
Laura M. Giovane ◽  
Hsin-Chiao Luan ◽  
Anuradha M. Agarwal ◽  
Lionel C. Kimerling
Keyword(s):  
Dislocation Density ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Buffer Layers ◽  
Threading Dislocation ◽  
Threading Dislocation Density

Influence of Ta2O5, TiO2, and ZrO2 Interfacial Layers on Structural and Electrical Properties of Laser Ablated Ba0.5Sr0.5TiO3 Thin Films

2002 ◽  
Vol 748 ◽  
Author(s):  
Suprem R. Das ◽  
Rasmi R. Das ◽  
P. Bhattacharya ◽  
Ram S. Katiyar
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Buffer Layers ◽  
Bst Thin Films ◽  
Interfacial Layers ◽  
Average Grain Size ◽  
Structural And Electrical Properties

ABSTRACTPulsed laser deposition technique was used to fabricate Ba0.5Sr0.5TiO 3 (BST) thin-films on Pt/TiO 2/SiO2/Si substrates. The influence of thin interfacial layers of Ta2O5, TiO2, and ZrO2, on the structural and electrical properties of BST thin films was investigated. Insertion of interfacial layers does not affect the perovskite phase formation of BST thin films. Buffer layers helped to make uniform distribution of grains and resulted in a relative increase in the average grain size. The dielectric tunability of BST thin films was reduced with the presence of buffer layers. A BST thin film having a dielectric permitivity of 470 reduced to 337, 235 and 233 in the presence of Ta2O5, TiO2, and ZrO2 layers, respectively. The reduction of the relative dielectric permittivity of BST films with the insertion of interfacial layers was explained in terms of a series capacitance effect, due to the low dielectric constant of interfacial layers. The TiO2 layer did not show any appreciable change in the leakage current density. Deposition of thin Ta2O5 and ZrO2 interfacial layer on top of Pt reduced the leakage current density by an order of magnitude.

The Reduction of The Defect Density in CdTe Buffer Layers for The Growth of HgCdTe Infrared Photodiodes on Si (211) Substrates

1997 ◽  
Vol 484 ◽  
Author(s):  
H.-Y. Wei ◽  
L. Salamanca-Riba ◽  
N. K. Dhar
Keyword(s):  
Dislocation Density ◽  
Defect Density ◽  
Three Dimensional ◽  
Buffer Layers ◽  
Threading Dislocation ◽  
Si Substrates ◽  
Migration Enhanced Epitaxy ◽  
Threading Dislocation Density ◽  
Order Of Magnitude ◽  
Cdte Buffer

CdTe epilayers were grown by molecular beam epitaxy on As-passivated nominal (211) Si substrates using thin interfacial ZnTe layers. By using thin recrystallized (initially amorphous) ZnTe buffei layers, we utilized migration enhanced epitaxy (MEE) in the ZnTe layer and overcome the tendency toward three dimensional nucleation. The threading dislocation densities in 8–9 tm thick CdTe films deposited on the recrystallized amorphous ZnTe films were in the range of 2 to 5 × 105 cm−2. In addition to the reduction of threading dislocation density, the interface between the ZnTe layers and the Si substrate is much smoother and the microtwin density is an order of magnitude lower than in regular MEE growth. In order to understand the initial nucleation mechanism of the ZnTe on the As precursor Si surface, we also grew ZnTe epilayers on Te precursor treated Si substrates. The growth mode, microtwin density, and threading dislocation density are compared for films grown on Si substrates with different surface precursors and grown by different growth methods.

Reverse Electrical Characteristics of 4H-SiC JBS Diodes Fabricated on In-House Substrate with Low Threading Dislocation Density

2011 ◽  
Vol 679-680 ◽  
pp. 694-697 ◽  
Author(s):  
Fujiwara Hirokazu ◽  
Masaki Konishi ◽  
T. Ohnishi ◽  
T. Nakamura ◽  
Kimimori Hamada ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Leakage Current ◽  
Surface Defects ◽  
High Yield ◽  
Threading Dislocation ◽  
Electrical Characteristics ◽  
Large Area ◽  
Low Leakage ◽  
Low Leakage Current ◽  
Threading Dislocation Density

The impacts of threading dislocations, surface defects, donor concentration, and schottky Schottky barrier height on the reverse IV characteristic of silicon carbide (SiC) junction barrier schottky Schottky (JBS) diodes were investigated. The 100 A JBS diodes were fabricated on 4H-SiC 3-inch N-type wafers with two types of threading dislocation density. The typical densities are were 0.2×104 and 3.8×104 cm-2, respectively. The improvement of vIt was found that variations in the leakage current and the high yield of large area JBS diodes werecould be were obtained improved by using a wafer with a low threading dislocation density. In the range of low leakage current, the investigation shows showed a correlation between leakage current and threading dislocation density.

The Reduction of The Defect Density in CdTe Buffer Layers for The Growth of HgCdTe Infrared Photodiodes on Si (211) Substrates

1997 ◽  
Vol 487 ◽  
Author(s):  
H.-Y. Wei ◽  
L. Salamanca-Riba ◽  
N. K. Dhar
Keyword(s):  
Dislocation Density ◽  
Defect Density ◽  
Three Dimensional ◽  
Buffer Layers ◽  
Threading Dislocation ◽  
Si Substrates ◽  
Migration Enhanced Epitaxy ◽  
Threading Dislocation Density ◽  
Order Of Magnitude ◽  
Cdte Buffer

CdTe epilayers were grown by molecular beam epitaxy on As-passivated nominal (211) Si substrates using thin interfacial ZnTe layers. By using thin recrystallized (initially amorphous) ZnTe buffer layers, we utilized migration enhanced epitaxy (MEE) in the ZnTe layer and overcome the tendency toward three dimensional nucleation. The threading dislocation densities in 8–9 μm thick CdTe films deposited on the recrystallized amorphous ZnTe films were in the range of 2 to 5 × 105 cm−2. In addition to the reduction of threading dislocation density, the interface between the ZnTe layers and the Si substrate is much smoother and the microtwin density is an order of magnitude lower than in regular MEE growth. In order to understand the initial nucleation mechanism of the ZnTe on the As precursor Si surface, we also grew ZnTe epilayers on Te precursor treated Si substrates. The growth mode, microtwin density, and threading dislocation density are compared for films grown on Si substrates with different surface precursors and grown by different growth methods.

Threading Dislocations in S-Graded ZnSxSe1-x/GaAs (001) Metamorphic Buffer Layers

2014 ◽  
Vol 23 (01n02) ◽  
pp. 1420005 ◽  
Author(s):  
Tedi Kujofsa ◽  
John E. Ayers
Keyword(s):  
Dislocation Density ◽  
Buffer Layer ◽  
Lattice Relaxation ◽  
Buffer Layers ◽  
Cumulative Distribution ◽  
Threading Dislocation ◽  
Threading Dislocations ◽  
Modeling Studies ◽  
Threading Dislocation Density ◽  
Dislocation Behavior

Metamorphic semiconductor devices are commonly fabricated with linearly-graded buffer layers, but equilibrium modeling studies suggest that S-graded buffers, following a normal cumulative distribution function, may enable lower threading defect densities. The present work involves a study of threading dislocation density behavior in S-graded ZnS x Se 1-x buffer layers for metamorphic devices on mismatched GaAs (001) substrates using a kinetic model for lattice relaxation and misfit-threading dislocation interactions. The results indicate that optimization of an S-graded buffer layer to minimize the surface threading dislocation density requires adjustment of the standard deviation parameter and cannot be achieved by varying the buffer thickness alone. Furthermore, it is possible to tailor the design of the S-graded buffer layer in such a way that the density of mobile threading dislocations at the surface vanishes. Nonetheless, the threading dislocation behavior in these heterostructures is quite complex, and a full understanding of their behavior will require further experimental and modeling studies.

Impact of Surface Morphology above Threading Dislocations on Leakage Current in 4H-SiC Diodes

2012 ◽  
Vol 717-720 ◽  
pp. 911-916 ◽  
Author(s):  
Fujiwara Hirokazu ◽  
T. Katsuno ◽  
Tsuyoshi Ishikawa ◽  
H. Naruoka ◽  
Masaki Konishi ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Leakage Current ◽  
Electric Fields ◽  
Schottky Diodes ◽  
Threading Dislocation ◽  
Threading Dislocations ◽  
Nano Scale ◽  
Threading Dislocation Density ◽  
Positive Correlations ◽  
The Impact

The impact of threading dislocation density on the leakage current of reverse IV characteristics in 1.2 kV Schottky barrier diodes (SBDs), junction barrier Schottky diodes (JBSDs), and PN junction diodes (PNDs) was investigated. The leakage current density and threading dislocation density have different positive correlations in each type of diode. For example, the correlation in SBDs is strong, but weak in PNDs. The threading dislocations were found to be in the same location as the current leakage points in the SBDs, but not in the PNDs. Nano-scale inverted cone pits were observed at the Schottky junction interface in SBDs, and it was found that leakage current increases in these diodes due to the concentration of electric fields at the peaks of the pits. These nano-scale pits were also observed directly above threading dislocations. In addition, this study succeeded in reducing the leakage current variation of 200 A-class JBSDs and SBDs by eliminating the nano-scale pits above the threading dislocations. As a result, a theoretical straight-line waveform was achieved.

Fabrication of relaxed GeSi buffer layers on Si(100) with low threading dislocation density

1992 ◽  
Vol 14 (3) ◽  
pp. 332-335 ◽  
Author(s):  
Y.H. Xie ◽  
E.A. Fitzgerald ◽  
P.J. Silverman ◽  
A.R. Kortan ◽  
B.E. Weir
Keyword(s):  
Dislocation Density ◽  
Buffer Layers ◽  
Threading Dislocation ◽  
Threading Dislocation Density

Efficient 350 nm LEDs on low edge threading dislocation density AlGaN buffer layers

2011 ◽  
Author(s):  
Richard Gutt ◽  
Thorsten Passow ◽  
Wilfried Pletschen ◽  
Michael Kunzer ◽  
Lutz Kirste ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Buffer Layers ◽  
Threading Dislocation ◽  
Threading Dislocation Density ◽  
Algan Buffer
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