NH 3 treatments of Hf-based layers for application as NVM active dielectrics

Marc Bocquet (1, 2) , G. Molas (1) , E. Martínez (1) , H. Grampeix (1) , F. Martin (1) , J P Colonna (1) , J Buckley (1) , C. Licitra (1) , N. Rochat (1) , T Veyron (1) , A M Papon (1) , F. Aussenac (1) , V. Delaye (1) , M. Gély (1) , G. Pananakakis (2) , B. de Salvo (1) , G. Ghibaudo (2) , S. Deleonibus (1)

1 CEA-LETI - Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information
2 IMEP-LAHC - Institut de Microélectronique, Electromagnétisme et Photonique - Laboratoire d'Hyperfréquences et Caractérisation

Introduction High-κ materials are currently under investigation for application to non volatile memories (NVMs) thanks to the important benefits they offer in terms of coupling, in particular when they are used as interpoly (IPD) layers 1-4. However, the important charge trap density which characterizes these new materials constitutes a serious roadblock, the device reliability being affected by the trap-assisted gate leakage currents 5. Hence, today a major challenge is the process control of the high-κ trapping properties. In this paper, we advance the state of the art on these topics by investigating the influence of nitrogen (N) incorporation, by ammonia (NH 3) treatments, on HfO 2 and HfAlO high-κ materials in the 6-14nm thickness range (suitable for NVM applications). Through physical and electrical analyses, we demonstrate that an appropriate nitridation can significantly reduce the parasitic charge trapping phenomena. We argue that the lower trapping behavior is related to a smaller ratio of the crystalline phase of the high-κ layers, which is indeed strictly linked to the nitridation process.

Domaines: Micro et nanotechnologies/Microélectronique

Marc Bocquet, G. Molas, E. Martínez, H. Grampeix, F. Martin, et al.. NH 3 treatments of Hf-based layers for application as NVM active dielectrics. IEEE Semiconductor Interface Specialists Conference (SISC), Dec 2007, Arlington, United States. ⟨hal-01745607⟩