TY - JOUR
T1 - Reaction chemistry during the atomic layer deposition of Sc 2O3 and Gd2O3 from Sc(MeCp) 3, Gd(iPrCp)3, and H2O
AU - Han, Jeong Hwan
AU - Nyns, Laura
AU - Delabie, Annelies
AU - Franquet, Alexis
AU - Van Elshocht, Sven
AU - Adelmann, Christoph
PY - 2014/2/11
Y1 - 2014/2/11
N2 - The reaction chemistry during the atomic layer deposition (ALD) of Sc 2O3 and Gd2O3 from Sc(MeCp) 3, Gd(iPrCp)3, and H2O was investigated by in situ time-resolved quadrupole mass spectrometry. Despite the similarity of the ligands of the Sc and Gd precursors, the growth characteristics and ligand dissociation patterns of the Sc2O 3 and Gd2O3 ALD processes showed considerably different behavior. For both processes, the precursors reacted with the hydroxylated surface by proton transfer and release of the protonated ligand. The remaining ligands were then removed by hydrolysis during the H2O pulse. However, for the Sc(MeCp)3/H2O process, ∼56% of MeCpH was released during the Sc(MeCp)3 exposure, whereas in the case of the Gd(iPrCp)3/H2O process, as much as 90% of iPrCpH was released during the Gd(iPrCp) 3 pulse. The observation that almost all iPrCp ligands were removed during the initial Gd(iPrCp)3 absorption step can be ascribed to CVD-like reactions between the Gd(iPrCp) 3 precursor and excess hydroxide or physisorbed H2O on the hygroscopic Gd2O3 surface. The influence of the growth temperature on the ligand exchange behavior and the resulting film properties (thickness uniformity, impurity concentration) was studied in the temperature range between 200 and 350 C. In addition, the transient growth behavior of Gd2O3 on Sc2O3 and vice versa was studied, indicating that the hygroscopic nature of Gd2O3 also strongly influences the deposition of GdxSc1-xO 3 ternary oxides.
AB - The reaction chemistry during the atomic layer deposition (ALD) of Sc 2O3 and Gd2O3 from Sc(MeCp) 3, Gd(iPrCp)3, and H2O was investigated by in situ time-resolved quadrupole mass spectrometry. Despite the similarity of the ligands of the Sc and Gd precursors, the growth characteristics and ligand dissociation patterns of the Sc2O 3 and Gd2O3 ALD processes showed considerably different behavior. For both processes, the precursors reacted with the hydroxylated surface by proton transfer and release of the protonated ligand. The remaining ligands were then removed by hydrolysis during the H2O pulse. However, for the Sc(MeCp)3/H2O process, ∼56% of MeCpH was released during the Sc(MeCp)3 exposure, whereas in the case of the Gd(iPrCp)3/H2O process, as much as 90% of iPrCpH was released during the Gd(iPrCp) 3 pulse. The observation that almost all iPrCp ligands were removed during the initial Gd(iPrCp)3 absorption step can be ascribed to CVD-like reactions between the Gd(iPrCp) 3 precursor and excess hydroxide or physisorbed H2O on the hygroscopic Gd2O3 surface. The influence of the growth temperature on the ligand exchange behavior and the resulting film properties (thickness uniformity, impurity concentration) was studied in the temperature range between 200 and 350 C. In addition, the transient growth behavior of Gd2O3 on Sc2O3 and vice versa was studied, indicating that the hygroscopic nature of Gd2O3 also strongly influences the deposition of GdxSc1-xO 3 ternary oxides.
UR - http://www.scopus.com/inward/record.url?scp=84894146868&partnerID=8YFLogxK
U2 - 10.1021/cm403390j
DO - 10.1021/cm403390j
M3 - Article
AN - SCOPUS:84894146868
SN - 0897-4756
VL - 26
SP - 1404
EP - 1412
JO - Chemistry of Materials
JF - Chemistry of Materials
IS - 3
ER -