Atomic Layer Deposition and In-situ Characterization of Ultraclean ...
Atomic Layer Deposition and In-situ Characterization of Ultraclean Lithium Oxide and Lithium Hydroxide Alexander C. Kozen*,1,2, Alexander J. Pearse1,2, Chuan-Fu Lin1,2, Marshall A. Schroeder1,2, Malachi Noked2,3, Sang Bok Lee3, Gary W. Rubloff1,2 1: Department of Materials Science & Engineering, University of Maryland, College Park, MD, USA 2: Institute for Systems Research, University of Maryland, College Park, MD, USA 3: Department of Chemistry, University of Maryland, College Park, MD, USA
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Intensity (arb. units)
O 1s
1200
O KLL
Li 1s
C 1s
1000
800
600 B.E. (eV)
400
200
0
Figure A1. In-situ XPS survey spectra of as-deposited ALD Li2O at 250˚C demonstrating ultraclean carbon-free nature of the as-deposited films. Carbon content is < .1% as determined by the signal to noise ratio of the data.
2
Figure A2. Real time, in-situ spectroscopic ellipsometric data during the ALD Li2O process at 250˚C. Inset: Close-up of the data showing 6 full ALD Li2O cycles. Note the large thickness increase after the LiOtBu pulse, and then the removal of the tertbutanol ligands during the H2O pulse.
3
Li 1s
225C Thermal 240C Thermal 265C Thermal 300C Thermal 225C Plasma 300C Plasma O 1s
225C Thermal 240C Thermal 265C Thermal 300C Thermal 225C Plasma 300C Plasma C 1s
Li 1s Li2O Frac. %
Li 1s Li2CO3 Position (eV)
Li 1s Total Atomic %
Li 1s Li2O Position (eV)
46.2
53.70
4.00
54.71
96.0
n/a
0
65.5
53.70
100
n/a
0
n/a
0
62
53.71
100
n/a
0
n/a
0
62.8
53.68
100
n/a
0
n/a
0
39.7
53.69
42.4
n/a
0
55.31
57.6
36.3
53.68
32.7
n/a
0
55.30
67.3
O 1s Total Atomic %
O 1s Li2O Position (eV)
53.5
528.50
3.2
531.11
96.8
n/a
0
34.5
528.50
85.8
531.20
14.2
n/a
0
37.9
528.50
84.2
531.19
15.8
n/a
0
37.2
528.50
84.7
531.23
15.3
n/a
0
47.3
528.50
20.1
n/a
0
531.86
80.0
48.9
528.50
14.7
n/a
0
531.86
85.3
O 1s Li2O Frac. %
Li 1s LiOH Position (eV)
O 1s LiOH Position (eV)
Li 1s LiOH Frac. %
O 1s LiOH Frac. %
O 1s Li2CO3 Position (eV)
Li 1s Li2O3 Frac. %
O 1s Li2O3 Frac. %
C 1s Total Atomic % C 1s Position (eV) 225C Thermal < 0.5 Too small to determine 240C Thermal < 0.5 Too small to determine 265C Thermal < 0.5 Too small to determine 300C Thermal < 0.5 Too small to determine 225C Plasma 13.0 290.11 300C Plasma 14.8 290.02 Thermal Process Stoichiometry Li:O Ratio (Total Atomic % Li:O Ratio (Total Li to O Li:O Ratio (Total Li to O Values) LiOH Component) Li2O Component) 225C Thermal 0.86 0.89 n/a 240C Thermal 1.90 n/a 2.21 265C Thermal 1.63 n/a 1.94 300C Thermal 1.69 n/a 1.99
Table A3. Table containing all XPS photoelectron peak assignments from this work.
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Figure A4. Tapping mode AFM topographic map of air-exposed Li2O deposited using LiOtBu and H2O at 250˚C. Film texture is likely due to the reaction of Li2O to form Li2CO3.
5
Figure A5. SEM images of air-exposed Li2O deposited using LiOtBu and H2O at 250˚C. Film texture is due to unavoidable electron beam-induced damage in the SEM.
6
Figure A6. (a, b, c) TEM images of ALD Li2O deposited using LiOtBu and H2O at 250˚C on to a MWCNT substrate demonstrating ability to conformally coat high aspect ratio nanostructures; (d) electron diffraction image of one Li2O crystal showing the plane.
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C 1s Intensity (arb. units)
Li2CO3
294 292 290 288 286 284 282 B.E. (eV)
Figure A7. XPS C1s photoelectron peak of LiOtBu powder loaded from an Ar glovebox without air exposure.
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1
Intensity (arb. units)
O 1s
1200
O KLL
Li 1s
C 1s
1000
800
600 B.E. (eV)
400
200
0
Figure A1. In-situ XPS survey spectra of as-deposited ALD Li2O at 250˚C demonstrating ultraclean carbon-free nature of the as-deposited films. Carbon content is < .1% as determined by the signal to noise ratio of the data.
2
Figure A2. Real time, in-situ spectroscopic ellipsometric data during the ALD Li2O process at 250˚C. Inset: Close-up of the data showing 6 full ALD Li2O cycles. Note the large thickness increase after the LiOtBu pulse, and then the removal of the tertbutanol ligands during the H2O pulse.
3
Li 1s
225C Thermal 240C Thermal 265C Thermal 300C Thermal 225C Plasma 300C Plasma O 1s
225C Thermal 240C Thermal 265C Thermal 300C Thermal 225C Plasma 300C Plasma C 1s
Li 1s Li2O Frac. %
Li 1s Li2CO3 Position (eV)
Li 1s Total Atomic %
Li 1s Li2O Position (eV)
46.2
53.70
4.00
54.71
96.0
n/a
0
65.5
53.70
100
n/a
0
n/a
0
62
53.71
100
n/a
0
n/a
0
62.8
53.68
100
n/a
0
n/a
0
39.7
53.69
42.4
n/a
0
55.31
57.6
36.3
53.68
32.7
n/a
0
55.30
67.3
O 1s Total Atomic %
O 1s Li2O Position (eV)
53.5
528.50
3.2
531.11
96.8
n/a
0
34.5
528.50
85.8
531.20
14.2
n/a
0
37.9
528.50
84.2
531.19
15.8
n/a
0
37.2
528.50
84.7
531.23
15.3
n/a
0
47.3
528.50
20.1
n/a
0
531.86
80.0
48.9
528.50
14.7
n/a
0
531.86
85.3
O 1s Li2O Frac. %
Li 1s LiOH Position (eV)
O 1s LiOH Position (eV)
Li 1s LiOH Frac. %
O 1s LiOH Frac. %
O 1s Li2CO3 Position (eV)
Li 1s Li2O3 Frac. %
O 1s Li2O3 Frac. %
C 1s Total Atomic % C 1s Position (eV) 225C Thermal < 0.5 Too small to determine 240C Thermal < 0.5 Too small to determine 265C Thermal < 0.5 Too small to determine 300C Thermal < 0.5 Too small to determine 225C Plasma 13.0 290.11 300C Plasma 14.8 290.02 Thermal Process Stoichiometry Li:O Ratio (Total Atomic % Li:O Ratio (Total Li to O Li:O Ratio (Total Li to O Values) LiOH Component) Li2O Component) 225C Thermal 0.86 0.89 n/a 240C Thermal 1.90 n/a 2.21 265C Thermal 1.63 n/a 1.94 300C Thermal 1.69 n/a 1.99
Table A3. Table containing all XPS photoelectron peak assignments from this work.
4
Figure A4. Tapping mode AFM topographic map of air-exposed Li2O deposited using LiOtBu and H2O at 250˚C. Film texture is likely due to the reaction of Li2O to form Li2CO3.
5
Figure A5. SEM images of air-exposed Li2O deposited using LiOtBu and H2O at 250˚C. Film texture is due to unavoidable electron beam-induced damage in the SEM.
6
Figure A6. (a, b, c) TEM images of ALD Li2O deposited using LiOtBu and H2O at 250˚C on to a MWCNT substrate demonstrating ability to conformally coat high aspect ratio nanostructures; (d) electron diffraction image of one Li2O crystal showing the plane.
7
C 1s Intensity (arb. units)
Li2CO3
294 292 290 288 286 284 282 B.E. (eV)
Figure A7. XPS C1s photoelectron peak of LiOtBu powder loaded from an Ar glovebox without air exposure.
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