Phase formation sequence in the Ti/InP system during thin film solid-state reactions

Elodie Ghegin (1, 2) , Philippe Rodriguez (2) , J.L. Labar (3) , M. Menyhard (3) , S. Favier (1, 2) , Isabelle Sagnes (4) , Fabrice Nemouchi (2)

1 ST-CROLLES - STMicroelectronics [Crolles]
2 CEA-LETI - Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information
3 MTA EK MFA, Konkoly Thege, Hungary
4 C2N - Centre de Nanosciences et de Nanotechnologies [Marcoussis]

The metallurgical properties of the Ti/InP system meet a great interest for its use as a contact in the scope of various applications such as the Si Photonics. The investigations conducted on this system highlight the initiation of a reaction between the Ti and the InP substrate during the deposition process conducted at 100 °C. The simultaneous formation of two binary phases, namely, Ti$_2$In$_5$ and TiP, is attributed to the compositional gradient induced in the InP by the wet surface preparation and enhanced by the subsequent $in situ$ Ar$^+$ preclean. Once formed, the TiP layer acts as a diffusion barrier inhibiting further reaction up to 450 °C in spite of the presence of an important Ti reservoir. At higher temperature, however, i.e., from 550 °C, the reaction is enabled either by the enhancement of the species diffusion through the TiP layer or by its agglomeration. This reaction gives rise to the total consumption of the Ti$_2$In$_5$ and Ti while the TiP and In phases are promoted.

Mots clés: III-V laser; Si Photonics; TiP; Ti2In5; In; InP; Ti; solid state reaction

Domaines: Matériaux

Elodie Ghegin, Philippe Rodriguez, J.L. Labar, M. Menyhard, S. Favier, et al.. Phase formation sequence in the Ti/InP system during thin film solid-state reactions. Journal of Applied Physics, 2017, 121, pp.245311. ⟨10.1063/1.4990427⟩. ⟨cea-01559841⟩