Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Laser-assisted atom probe tomography of c-plane and m-plane InGaN test
  structures   Laser-assisted atom probe tomography (APT) was used to measure the indium
mole fraction x of c-plane, MOCVD-grown, GaN/In(x)Ga(1-x)N/GaN test structures
and the results were compared with Rutherford backscattering analysis (RBS).
Four sample types were examined with (RBS determined) x = 0.030, 0.034, 0.056,
and 0.112. The respective In(x)Ga(1-x)N layer thicknesses were 330 nm, 327 nm,
360 nm, and 55 nm. APT data were collected at (fixed) laser pulse energy (PE)
selected within the range of (2-1000) fJ. Sample temperatures were = 54 K. PE
within (2-50) fJ yielded x values that agreed with RBS (within uncertainty) and
were comparatively insensitive to region-of-interest (ROI) geometry and
orientation. By contrast, approximate stoichiometry was only found in the GaN
portions of the samples provided PE was within (5-20) fJ and the analyses were
confined to cylindrical ROIs (of diameters =20 nm) that were coaxial with the
specimen tips. m-plane oriented tips were derived from c-axis grown,
core-shell, GaN/In(x)Ga(1-x)N nanorod heterostructures. Compositional analysis
along [0 0 0 1] (transverse to the long axis of the tip), of these m-plane
samples revealed a spatial asymmetry in charge-state ratio (CSR) and a
corresponding asymmetry in the resultant tip shape along this direction; no
asymmetry in CSR or tip shape was observed for analysis along [-1 2-1 0].
Simulations revealed that the electric field strength at the tip apex was
dominated by the presence of a p-type inversion layer, which developed under
typical tip-electrode bias conditions for the n-type doping levels considered.
Finally, both c-plane and m-plane sample types showed depth-dependent
variations in absolute ion counts that depended upon ROI placement.

31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
24
The categories of this paper are: dg-ga
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
29
The categories of this paper are: funct-an
25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg
14
The categories of this paper are: math-ph
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
10
The categories of this paper are: q-bio
1
The categories of this paper are: cs
13
The categories of this paper are: quant-ph
15
The categories of this paper are: nucl-ex