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 (%

)