| AVS 63rd International Symposium & Exhibition | |
| Thin Film | Monday Sessions |
| Session TF-MoM |
| Session: | ALD Precursors and Surface Reactions |
| Presenter: | Brent Sperling, National Institute of Standards and Technology (NIST) |
| Authors: | B.A. Sperling, National Institute of Standards and Technology (NIST) J.E. Maslar, National Institute of Standards and Technology (NIST) B. Kalanyan, National Institute of Standards and Technology (NIST) |
| Correspondent: | Click to Email |
Atomic layer deposition (ALD) of La2O3-containing films is of interest for high-k dielectric layers in semiconductor manufacturing. Characterization of as-deposited films is made difficult by the tendency of La2O3 to form lanthanum carbonates and hydroxides upon exposure to the atmosphere. Previous in situ studies have shown evidence for the formation of carbonates during the actual deposition process using an amidinate and water. Ex situ studies have found unusual growth behavior that is typically attributed to lanthanum hydroxide formation during deposition. One of the strategies often employed for establishing typical ALD-type growth in La2O3-containing films is the incorporation of a second oxide. Although known to be effective, the reasons why are not known. Here, we use time-resolved IR spectroscopy to study surface reactions during La2O3/Al2O3 nanolaminate formation. A laminar flow reactor using La(iPrCp)3, TMA, and H2O as precursors is used. We show that, contrary to previous speculation, non-ideal growth is not due to hydroxide formation. The benefits of incorporating the second oxide is unrelated to suppressing lanthanum hydroxide; alternate explanations must be considered.