Abstract
Niobium pentoxide was deposited using tBuN=Nb(NEt2)3 as niobium precursor by both thermal atomic layer deposition (ALD) and plasma-enhanced atomic layer deposition (PE-ALD) with H2O and O2 plasma as coreactants, respectively. The deposition temperature was varied between 150 and 350 °C in both ALD processes. Amorphous films were obtained in all cases. Self-limiting saturated growth was confirmed for both ALD processes along with high uniformity over a 200 mm Si wafer. The PE-ALD process enabled a higher growth per cycle (GPC) than the thermal ALD process (0.56 Å vs 0.38 Å at 200 °C, respectively), while the GPC decreases with increasing temperature in both cases. The high purity of the film was confirmed using Rutherford backscattering spectrometry, elastic recoil detection, and x-ray photoelectron spectroscopy, while the latter technique also confirmed the Nb+5 oxidation state of the niobium oxide films. The thermal ALD deposited films were substoichiometric due to the presence of oxygen vacancies (VO), of which a more dominant presence was observed with increasing deposition temperature. The PE-ALD deposited films were found to be near stoichiometric for all investigated deposition temperatures.
Original language | English |
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Article number | 041503 |
Number of pages | 25 |
Journal | Journal of Vacuum Science and Technology A |
Volume | 36 |
Issue number | 4 |
DOIs | |
Publication status | Published - 1 Jul 2018 |