(see bowen & tanner, high resolution x-ray …thin films (see bowen & tanner, high...
TRANSCRIPT
![Page 1: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/1.jpg)
Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3)
Common epilayer defects
![Page 2: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/2.jpg)
Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3)
Common epilayer defects
Investigate using rocking
curves
![Page 3: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/3.jpg)
Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3)
Common epilayer defects
Investigate using rocking
curves
Layer & substrate peaks split
rotation invariant
![Page 4: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/4.jpg)
Thin films
Common epilayer defects
Investigate using rocking
curves
Layer & substrate peaks split
varies w/rotation
![Page 5: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/5.jpg)
Thin films
Common epilayer defects
Investigate using rocking
curves
Broadens layer peak
invariant w/ beam size
peak position invariant
w/ sample position
![Page 6: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/6.jpg)
Thin films
Common epilayer defects
Investigate using rocking
curves
Broadens layer peak
may increase w/ beam
size
peak position invariant
w/ sample position
![Page 7: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/7.jpg)
Thin films
Common epilayer defects
Investigate using rocking
curves
Broadens layer peak
increases w/ beam size
peak position varies
w/ sample position
![Page 8: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/8.jpg)
Thin films
Common epilayer defects
Investigate using rocking
curves
Layer & substrate peaks split
splitting different for
symmetric & asymmetric
reflections
![Page 9: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/9.jpg)
Thin films
Common epilayer defects
Investigate using rocking
curves
Various effects
vary w/ sample position
![Page 10: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/10.jpg)
Thin films
Investigate using rocking
curves
Film thickness
Integrated intensity changes
increases w/ thickness
Interference fringes
![Page 11: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/11.jpg)
Thin films
Mismatch
constrained relaxed
![Page 12: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/12.jpg)
Thin films
Mismatch
Layer & substrate peaks split – rotation invariant
Measure, say, (004) peak separation , from which
d/d = – cot = m* (mismatch)
constrained relaxed
![Page 13: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/13.jpg)
Thin films
Misorientation
First, determine orientation of substrate
rotate to bring plane
normal into counter plane
do scans at this position
and at + 180°
orientation angle = 1/2
difference in two angles
= 90°
![Page 14: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/14.jpg)
Thin films
Misorientation
First, determine orientation of substrate
Layer tilt (assume small)
layer peak shifts w/
in scans
= 90°
shift +
![Page 15: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/15.jpg)
Thin films
Misorientation
First, determine orientation of substrate
Layer tilt (assume small)
layer peak shifts w/
in scans
= 90°
shift –
![Page 16: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/16.jpg)
Thin films
Misorientation
First, determine orientation of substrate
Layer tilt (assume small)
layer peak shifts w/
in scans
= 90°
no shift
![Page 17: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/17.jpg)
Thin films
Misorientation
First, determine orientation of substrate
Layer tilt (assume small)
layer peak shifts w/
in scans
= 90°
no shift
![Page 18: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/18.jpg)
Thin films
Dislocations
From:
high mismatch strain, locally relaxed
local plastic deformation due to strain
growth dislocations
![Page 19: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/19.jpg)
Thin films
Dislocations
From:
high mismatch strain, locally relaxed
local plastic deformation due to strain
growth dislocations
Estimate dislocation density from broadening (radians)
& Burgers vector b (cm):
= 2/9b2
![Page 20: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/20.jpg)
Thin films
Curvature
R = radius of curvature, s = beam diameter
angular broadening = s/R =
beam radius broadening
5 mm 100 m 10"
![Page 21: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/21.jpg)
Thin films
Relaxation
Need to measure misfit
parallel to interface
Both mismatch &
misorientation change
on relaxation
Interplanar spacings change with mismatch distortion &
relaxation – changes splittings
![Page 22: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/22.jpg)
Thin films
Relaxation
Need to measure misfit
parallel to interface
Both mismatch &
misorientation change
on relaxation
So, also need misfit perpendicular to interface
Then, % relaxation is
![Page 23: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/23.jpg)
Thin films
Relaxation
Grazing incidence
Incidence angle usually
very low….~1-2°
Limits penetration of
specimen
reflecting plane
![Page 24: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/24.jpg)
Thin films
Relaxation
Grazing incidence
Incidence angle usually
very low….~1-2°
Limits penetration of
specimen
Penetration depth – G(x) = fraction of total diffracted intensity from layer x
cm thick compared to infinitely thick specimen
![Page 25: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/25.jpg)
Thin films
Relaxation
Grazing incidence
Incidence angle usually
very low….~1-2°
Limits penetration of
specimen
Penetration depth – G(x) = fraction of total diffracted intensity from layer x
cm thick compared to infinitely thick specimen
![Page 26: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/26.jpg)
Thin films
Relaxation
Grazing incidence
Incidence angle usually
very low….~1-2°
Reflection not from
planes parallel to
specimen surface
reflecting plane
![Page 27: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/27.jpg)
Thin films
Relaxation
Grazing incidence
If incidence angle ~0.1-5° & intensity measured in
symmetric geometry (incident angle = reflected angle),
get reflectivity curve
![Page 28: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/28.jpg)
Thin films
Relaxation
Need to measure misfit
parallel to interface
Use grazing incidence
e.g., (224) or (113)
![Page 29: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/29.jpg)
Thin films
Relaxation
Use grazing incidence
e.g., (224) or (113)
Need to separate tilt
from true splitting
Tilt effect reversed
on rotation of = 180°
Mismatch splitting
unchanged on rotation
![Page 30: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/30.jpg)
Thin films
Relaxation
Use grazing incidence
e.g, (224) or (113)
For grazing incidence:
i = +
– splitting
betwn substrate
& layer
![Page 31: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/31.jpg)
Thin films
Relaxation
Use grazing incidence
e.g, (224) or (113)
For grazing incidence:
i = +
e = –
Can thus get both
and
![Page 32: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/32.jpg)
Thin films
Relaxation
Also,
And
![Page 33: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/33.jpg)
Thin films
Relaxation
Also,
And
Finally
![Page 34: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/34.jpg)
Thin films
Homogeneity
Measure any significant parameter over a grid on specimen
Ex: compositional variation
get composition using Vegards law
measure lattice parameter(s) – calculate relaxed mismatch
![Page 35: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/35.jpg)
Thin films
Homogeneity
Measure any significant parameter over a grid on specimen
Ex: variation of In content in InAlAs layer on GaAs
![Page 36: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/36.jpg)
Thin films
Thickness
For simple structure layer, layer peak integrated intensity
increases monotonically w/ thickness
calculated curves
![Page 37: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/37.jpg)
Thin films
Thickness
For simple structure layer, layer peak integrated intensity
increases monotonically w/ thickness
Note thickness fringes
Can use to estimate
thickness
calculated curves
![Page 38: (see Bowen & Tanner, High Resolution X-ray …Thin films (see Bowen & Tanner, High Resolution X-ray Diffractometry and Topography, Chap. 3) Common epilayer defects Investigate using](https://reader033.vdocuments.mx/reader033/viewer/2022042312/5edb2f79d96bc859bd1d6a89/html5/thumbnails/38.jpg)
Thin films
Thickness
For simple structure layer, layer peak integrated intensity
increases monotonically w/ thickness
calculated curves