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. 2022 Nov 28;12:20431. doi: 10.1038/s41598-022-23395-3

Table 2.

Summary of the XPS Analysis of surface composition of different sensor chips before and after cleaning procedures.

LTCC Gold
Au 4f
Carbon
C 1s
Oxygen
O 1s
Iodine
I 3d5/2
Silver
Ag 3d5/2
Other elements
Uncleaned 21.7 ± 5.3 61.7 ± 5.4 15.7 ± 0.1 0.4 ± 0.1 0.6 ± 0.2 -
UV-O3 60.4 ± 3.9 21.4 ± 1.5 15.7 ± 1.7 0.4 ± 0.2 2.2 ± 0.6 -
Piranha 70.1 ± 0.3 23.1 ± 1.1 6.3 ± 1.2 0.2 ± 0.1 0.5 ± 0.1 -
KOH + H2O2 64.4 ± 3.0 23.4 ± 1.3 8.6 ± 0.2 0.5 ± 0.3 3.2 ± 1.2 -
KOH + H2O2/KOH sweep 62.1 ± 4.0 20.2 ± 1.3 16.5 ± 7.3 - 1.3 ± 0.0 -
H2SO4 CV 70.1 ± 1.2 22.5 ± 1.7 5.9 - 1.6 ± 0.0 -
PEN Gold
Au 4f
Carbon
C 1s
Oxygen
O 1s
Iodide
I 3d5/2
Silver
Ag 3d5/2
Fluorine
F 1s
Uncleaned 46.2 ± 5.9 34.5 ± 5.5 12.7 ± 1.6 4.9 ± 1.4 0.2 ± 0.0 1.7 ± 0.3
UV-O3 49.3 ± 1.0 31.1 ± 0.5 19.6 ± 0.6 - 0.1 ± 0.1 -
Piranha 54.8 ± 3.0 29.6 ± 1.4 11.4 ± 1.7 3.8 ± 2.3 - 0.5 ± 0.5
KOH + H2O2 62.4 ± 0.7 28.8 ± 0.5 8.6 ± 0.1 - 0.3 ± 0.1 -
KOH + H2O2/KOH Sweep 66.7 ± 1.4 25.7 ± 0.9 7.3 ± 0.4 - 0.3 ± 0.1 -
H2SO4 CV 57.9 ± 1.1 29.4 ± 0.9 12.6 ± 0.2 - 0.1 ± 0.1 -
PCB Gold
Au 4f
Carbon
C 1s
Oxygen
O 1s
Nickel
Ni 2p3/2
Silicon
Si 2s
Nitrogen
N 1s
Uncleaned 20.9 ± 0.1 38.1 ± 2.1 26.4 ± 0.5 2.3 ± 0.1 10.1 ± 2.4 2.3 ± 0.5
UV-O3 43.3 ± 3.3 29.6 ± 2.6 19.5 ± 3.6 3.0 ± 1.8 1.5 ± 1.5 1.8 ± 0.6
Piranha 15.3 ± 4.9 33.7 ± 4.5 36.3 ± 0.9 11.9 ± 0.6 1.0 ± 0.9 -
KOH + H2O2 49.2 ± 2.4 27.8 ± 0.8 16.9 ± 0.9 3.3 ± 0.8 0.8 ± 0.8 2.1 ± 0.8
KOH + H2O2/KOH Sweep 46.2 ± 1.8 29.3 ± 0.8 20.1 ± 0.3 4.6 ± 0.8 - 2.1 ± 0.8

Elemental concentrations are given in percent. Measurements are averaged over multiple samples.