Atomic Layer Deposition of Titanium Oxide-Based Films for Semiconductor Applications-Effects of Precursor and Operating Conditions

Vladyslav Matkivskyi; Oskari Leiviskä; Sigurd Wenner; Hanchen Liu; Ville Vähänissi; Hele Savin; Marisa Di Sabatino; Gabriella Tranell

doi:10.3390/ma16165522

Atomic Layer Deposition of Titanium Oxide-Based Films for Semiconductor Applications-Effects of Precursor and Operating Conditions

Materials (Basel). 2023 Aug 8;16(16):5522. doi: 10.3390/ma16165522.

Authors

Vladyslav Matkivskyi¹, Oskari Leiviskä², Sigurd Wenner³, Hanchen Liu², Ville Vähänissi², Hele Savin², Marisa Di Sabatino¹, Gabriella Tranell¹

Affiliations

¹ Department of Materials Science and Engineering, Norwegian University of Science and Technology, Alfred Getz vei 2B, 7034 Trondheim, Norway.
² Department of Electronics and Nanoengineering, Aalto University, Tietotie 3, 02150 Espoo, Finland.
³ SINTEF Industry, Høgskoleringen 5, 7034 Trondheim, Norway.

Abstract

Two widely used atomic layer deposition precursors, Tetrakis (dimethylamido) titanium (TDMA-Ti) and titanium tetrachloride (TiCl₄), were investigated for use in the deposition of TiOx-based thin films as a passivating contact material for solar cells. This study revealed that both precursors are suited to similar deposition temperatures (150 °C). Post-deposition annealing plays a major role in optimising the titanium oxide (TiO_x) film passivation properties, improving minority carrier lifetime (τ_eff) by more than 200 µs. Aluminium oxide deposited together with titanium oxide (AlO_y/TiO_x) reduced the sheet resistance by 40% compared with pure TiO_x. It was also revealed that the passivation quality of the (AlO_y/TiO_x) stack depends on the precursor and ratio of AlO_y to TiO_x deposition cycles.

Keywords: ALD precursors; atomic layer deposition; passivation films; titanium oxide.

Grants and funding

The FIB preparation was performed at the SMART-H infrastructure, funded by The Research Council of Norway (RCN), grant 296197. The TEM work was carried out at the NORTEM infrastructure, RCN grant 197405.