| AVS 55th International Symposium & Exhibition | |
| Thin Film | Tuesday Sessions |
| Session TF-TuA |
| Session: | Applications of ALD II |
| Presenter: | Y. Liu, Harvard University |
| Authors: | Y. Liu, Harvard University H. Kim, Harvard University J.J. Wang, Harvard University R.G. Gordon, Harvard University H. Li, Rohm and Haas Electronic Materials D.V. Shenai, Rohm and Haas Electronic Materials |
| Correspondent: | Click to Email |
Amorphous lanthanum aluminum oxide (LaAlO3) films were deposited on hydrogen-terminated silicon substrates by atomic layer deposition (ALD) at 300 oC. Capacitance-voltage measurements made from ALD MoN/LaAlO3/Si stacks showed humps especially at low frequencies, indicating traps for electrons or holes. Two sources of these traps were identified: impurities and oxygen vacancies. The number of traps was cut in half by careful purification of the La precursor to remove metallic impurities to below a total of 1 ppm. The remaining traps were effectively removed by adding an oxygen (O2) exposure either after each ALD cycle or by a post-deposition O2 treatment at 300 oC, without affecting the dielectric constant (κ~15). The O2 treatment also lowered the leakage current by an order of magnitude, to 1 mA cm-2 for films with EOT = 1.3 nm.