Atomic layer deposition of conductive SnO2 thin films using Sn(dmamp)2 and H2O2 for templating rutile TiO2 growth

초록

Low-resistivity SnO2 films were synthesized via atomic layer deposition (ALD) using Sn(dmamp)2 as the Sn precursor and H2O2 as the oxidant. The adoption of H2O2 facilitated a high growth per cycle ranging from 0.11 to 0.15 nm/cycle as a function of the growth temperature, which is more than three times higher than those of ozone-based ALD processes. The deposited films exhibited high density of 5.8 g/cm3 and a Hall mobility of 20.85 cm2/V & sdot;s, demonstrating remarkable electrical characteristics. They also exhibited low impurity levels in the deposition temperature range. Furthermore, rutile phase crystallization was achieved within the ALD window without post-deposition annealing, highlighting the intrinsic crystallization capability of this process. By leveraging this property, an ultrathin SnO2 layer was employed as a seed template to promote the growth of rutile TiO2. This approach allowed low-temperature crystallization and increased the dielectric constant of TiO2 beyond 88 when integrated into metal-insulator-metal capacitors. Overall, this study demonstrates a viable ALD strategy for producing low-resistivity crystalline SnO2 films with high throughput and excellent electrical properties, enabling their use as functional layers in nanoelectronic devices.

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