FE-SEM foil thickness measurements
Process
• Mount sister foils to Si wafers– Static for thinner foils– “glue” with aerodag carbon suspension for thicker
• Mamun makes images• Use ImageJ software to measure .tiff images
saved from FE-SEM process
Comparison of edge find tool• Analyzed images 05 and 06 with edge contrast on or off• Find that the edge contrast tends to skew measurements slightly larger
– Variation between images larger than variation between images• Conclusion:
– make sure to go on inside edges of “edge find” line to get more accurate results
image 02 image 05 image 060.36
0.365
0.37
0.375
0.38
0.385
0.39
0.395
0.4
0.405
original image ana-lyzed
edge find
Mea
sure
d th
ickn
ess
Image 06 Measurement with and without edge find
Image 05: original image, edge find
Statistical analysis of points measuredspots selected by eye, original image
0.377916257082865
0.38206086536083
0.386205473638795
0.39035008191676
0.394494690194726
0.398639298472691
0.4027839067506560
2
4
6
8
10
12
14
16
18
film thickness
data
poi
nts i
n bi
n
Thickness distribution, edge find 5613D image05, spots selected by eye
0.381264882544044
0.383468483201118
0.385672083858192
0.387875684515265
0.390079285172339
0.392282885829413
0.394486486486487
0.39669008714356
0.398893687800634
0.401097288457708
0.403300889114782
0.405504489771855
0.407708090428929
0.4099116910860030
1
2
3
4
5
6
7
8
9
10
bins for foil thickness
mea
sure
men
ts in
bin
s
Statistics from even distribution 5613 M05 even stripe distance (don’t skip any oddities)
0
1
2
3
4
5
6
7
8
9
10
Frequency; 0
Freq
uenc
y
5613D
Image 03: 360 ± 17 nm
Image 05: 397 ± 10 nm
Image 06: 392 ± 10.5 nm
Conclusions: 5613D
Original image, Weighted mean 0.388 microns ± 0.0022
Edge find image, Weighted mean 0.392 microns ± 0.0036
image 02 image 05 image 060.36
0.365
0.37
0.375
0.38
0.385
0.39
0.395
0.4
0.405
Effect of measurement style
original image analyzed edge find even stripes
Mea
sure
d th
ickn
ess
Even stripes image, Weighted mean 0.389 microns ± 0.0066
Thickness is robust to within error bars for any of the methods
Foil 5134
782 ± 16 nm 772 ± 13 nm
Average: 776 nm ± 10.1
Foil 6809
Image 03: 54.005 +/- 3.443
Image 04: 51.254 ± 2.766 nm
Image 06: 51.824 ± 2.252 nm
51.539 ± 2.766
Ladder position Foil number Quoted thickness (nm) Measured thickness (nm)
13 6845 50 ± 5 51.539 ± 2.766
1 7029 225 ± 22.5
8 5613 350 ± 35 389 ± 6.6
5 5275 500 ± 50
2 7028 625 ± 62.5
4 5134 750 ± 75 776 nm ± 10.1
3 3057 870 ± 87
15 5385 1000 ± 100
0 0.2 0.4 0.6 0.8 1 1.230
32
34
36
38
40
42
44
Asymmetry vs. Foil thickness
Jan 2015fitmeasured thicknesses
Foil thickness (um)
Mea
sure
d As
ym (%
)