1. Planarization of flexible ceramic substrates
Yttria-stabilized zirconia (YSZ) substrates
Substrate characteristics
- Flexible YSZ substrate (ENrG, USA)
- RMS roughness: 27.2 nm
- typical peak-to-valley distance: 100 nm
- dimensions: 40 microns (thickness), 10 mm (width)
Flexible YSZ substrate planarization with Y2O3 layers
a. Multi-layer deposition
- 4 consecutive Y2O3 layers were deposited on YSZ substrate, each undergoing an individual heat treatment
- the RMS roughness decreases from 27.2 nm for the bare substrate to 15.7 nm (4 layers)
- the layer roughness varies slightly after the second layer deposition
- RMS roughness evolution with layer number and AFM analyses are shown below
b. YSZ substrate functionalization and Y2O3 single film deposition
- the substrate surface was functionalized with a tetraethoxysilan (TEOS)/ethanol mixture 3:10 and subsequent ammonia addition, followed by a heat treatment (1h at 200 °C)
- a single Y2O3 layer was deposited by chemical solution deposition, from a propionate based coating solution with 20 % vol. added glycerol
- exeptionally low RMS roughness, 4.7 nm, was obtained
- AFM image and typical height profile are shown below