Freestanding CVD diamond elaborated by pulsed-microwave-plasma for ZnO/diamond SAW devices

Structural and electrical properties of ZnO films on freestanding thick diamond films

“…ZnO has been of great interest [1] for many applications such as photoelectrical devices [2][3][4][5] , low loss optical waveguides [6] , and surface acoustic wave (SAW) devices [7][8][9][10][11][12][13][14] due to its structural, electrical, and optical properties. Recently, much attention has been paid to high quality piezoelectric ZnO films for SAW devices with operation frequencies higher than 1 GHz, whereas even greater frequencies (superior to 2.5 GHz) tend to push the limits of conventional photolithography [8] .…”

“…Recently, much attention has been paid to high quality piezoelectric ZnO films for SAW devices with operation frequencies higher than 1 GHz, whereas even greater frequencies (superior to 2.5 GHz) tend to push the limits of conventional photolithography [8] . The use of ZnO based on diamond as SAW substrates [8][9][10][11][12][13][14] offers an attractive means for relaxation of the lithographic criteria since diamond has the highest stiff coefficient and sound velocity. SAW devices have been reported based on ZnO/ diamond/Si layered structures with a diamond layer of 10-100 μm deposited by chemical vapour deposition (CVD) technique [9][10][11][12][13][14] .…”

“…SAW devices have been reported based on ZnO/ diamond/Si layered structures with a diamond layer of 10-100 μm deposited by chemical vapour deposition (CVD) technique [9][10][11][12][13][14] . However, the silicon substrate restricts the heat dissipation performance of the diamond films.…”

Heteroepitaxial ZnO films on diamond: Optoelectronic properties and the role of interface polarity

“…In combination with piezoelectric ZnO films, acoustic velocities up to 10 km/s could be realized at operating frequencies in the gigahertz regime. [1][2][3][4][5] However, the poor quality of the ZnO films on diamond fabricated by magnetron sputtering 6,7 or CVD 8 hindered the development towards optoelectronic or electronic devices. Consequently, the attempts to realize p-diamond/ n-ZnO heterodiodes did not yield promising results.…”

Magnetic tunnel junctions with a zinc oxide–cobalt oxide composite tunnel barrier

“…A 120 W dc power is applied on a planar magnetron for ZnO deposition at 0.8 Å / s. These optimized deposition conditions lead to good piezoelectric quality and stoichiometric ZnO thin films. 18 Finally, the sample is again brought back to the air and transferred for deposition of the top Co layer referred to as Co * is deposited at 1.5· 10 −2 mbar. The films deposited at this high pressure have an increased coercivity field of about 200 Oe at room temperature compared to 65 Oe for the bottom electrode.…”