Indium content measurements in metamorphic high electron mobility transistor structures by combination of x-ray reciprocal space mapping and transmission electron microscopy

2003 ◽  
Vol 93 (7) ◽  
pp. 4219-4225 ◽  
Author(s):  
J.-M. Chauveau ◽  
Y. Androussi ◽  
A. Lefebvre ◽  
J. Di Persio ◽  
Y. Cordier
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Mobility ◽  
High Electron Mobility Transistor ◽  
Indium Content ◽  
High Electron ◽  
Reciprocal Space Mapping ◽  
High Electron Mobility ◽  
X Ray ◽  
Transmission Electron

Quantitative Strain and Compositional Studies of InxGa1−xAs Epilayer in a GaAs-based pHEMT Device Structure by TEM Techniques

2014 ◽  
Vol 20 (4) ◽  
pp. 1262-1270 ◽  
Author(s):  
Duggi V. Sridhara Rao ◽  
Ramachandran Sankarasubramanian ◽  
Kuttanellore Muraleedharan ◽  
Thorsten Mehrtens ◽  
Andreas Rosenauer ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Electron Mobility Transistor ◽  
Growth Direction ◽  
Indium Content ◽  
Dark Field ◽  
High Electron ◽  
Device Structure ◽  
Channel Layer ◽  
Transmission Electron

AbstractIn GaAs-based pseudomorphic high-electron mobility transistor device structures, strain and composition of the InxGa1−xAs channel layer are very important as they influence the electronic properties of these devices. In this context, transmission electron microscopy techniques such as (002) dark-field imaging, high-resolution transmission electron microscopy (HRTEM) imaging, scanning transmission electron microscopy-high angle annular dark field (STEM-HAADF) imaging and selected area diffraction, are useful. A quantitative comparative study using these techniques is relevant for assessing the merits and limitations of the respective techniques. In this article, we have investigated strain and composition of the InxGa1−xAs layer with the mentioned techniques and compared the results. The HRTEM images were investigated with strain state analysis. The indium content in this layer was quantified by HAADF imaging and correlated with STEM simulations. The studies showed that the InxGa1−xAs channel layer was pseudomorphically grown leading to tetragonal strain along the [001] growth direction and that the average indium content (x) in the epilayer is ~0.12. We found consistency in the results obtained using various methods of analysis.

scholarly journals Effect of screw threading dislocations and inverse domain boundaries in GaN on the shape of reciprocal-space maps

2017 ◽  
Vol 50 (2) ◽  
pp. 555-560 ◽  
Author(s):  
Mykhailo Barchuk ◽  
Mykhaylo Motylenko ◽  
Gleb Lukin ◽  
Olf Pätzold ◽  
David Rafaja
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Reciprocal Space ◽  
Threading Dislocations ◽  
X Ray Diffraction ◽  
Reciprocal Space Mapping ◽  
Vapour Phase Epitaxy ◽  
X Ray ◽  
Transmission Electron ◽  
Domain Boundaries

The microstructure of polar GaN layers, grown by upgraded high-temperature vapour phase epitaxy on [001]-oriented sapphire substrates, was studied by means of high-resolution X-ray diffraction and transmission electron microscopy. Systematic differences between reciprocal-space maps measured by X-ray diffraction and those which were simulated for different densities of threading dislocations revealed that threading dislocations are not the only microstructure defect in these GaN layers. Conventional dark-field transmission electron microscopy and convergent-beam electron diffraction detected vertical inversion domains as an additional microstructure feature. On a series of polar GaN layers with different proportions of threading dislocations and inversion domain boundaries, this contribution illustrates the capability and limitations of coplanar reciprocal-space mapping by X-ray diffraction to distinguish between these microstructure features.

Impact of AlN Spacer on Electron Mobility of AlGaN/AlN/GaN Structures on Silicon

2013 ◽  
Vol 740-742 ◽  
pp. 502-505 ◽  
Author(s):  
Sebastian Roensch ◽  
Victor Sizov ◽  
Takuma Yagi ◽  
Saad Murad ◽  
Lars Groh ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Mobility ◽  
High Electron Mobility Transistor ◽  
Strong Impact ◽  
High Electron ◽  
High Electron Mobility ◽  
Alloy Scattering ◽  
The Impact ◽  
Scanning Electron

The impact of the thickness of an AlN spacer in AlGaN/AlN/GaN high electron mobility transistor (HEMT) structures on the Hall mobility was investigated in a range of 30 K - 340 K. The AlN spacer has a strong impact on the mobility at temperatures below 150 K. This effect is linked to a reduction of alloy scattering. Optical and scanning electron microscopy revealed hexagonal shaped defects which also have an effect on the mobility. These defects can be avoided by an appropriate adjustment of the AlN layer thickness.

Sign in / Sign up

Export Citation Format

Share Document