TY - JOUR
T1 - Comparison of thermal and plasma-enhanced atomic layer deposition of niobium oxide thin films
AU - Basuvalingam, S.B.
AU - Macco, B.
AU - Knoops, H.C.M.
AU - Melskens, J.
AU - Kessels, W.M.M.
AU - Bol, A.A.
PY - 2018/7/1
Y1 - 2018/7/1
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=85048586016&partnerID=8YFLogxK
U2 - 10.1116/1.5034097
DO - 10.1116/1.5034097
M3 - Article
AN - SCOPUS:85048586016
SN - 0734-2101
VL - 36
JO - Journal of Vacuum Science and Technology A: Vacuum, Surfaces, and Films
JF - Journal of Vacuum Science and Technology A: Vacuum, Surfaces, and Films
IS - 4
M1 - 041503
ER -