Phase Change Random Access Memories (PCRAM) are among the most mature non-volatile emerging memories (NVM): they allow data storage at high programing speed with enhanced endurance compared to today Flash technology1,2, as recently demonstrated by the INTEL OPTANETM 2,3. PCRAM are based on the ultrafast (<10 ns)4 and reversible transition between the amorphous and crystalline states of phase change materials (PCMs) initially used for optical data storage5. Data are stored thanks to the high resistivity contrast between these two structural phases of PCMs, the crystalline phase having a low resistance state, and the amorphous one a high resistance state6. Both amorphous and crystalline states of PCMs exhibits also very different optical properties, and are stable enough to be used as 0 and 1 states in non-volatile memories. The most promising PCM for NVM is the chalcogenide GexSbyTez (GST) used by STMicroelectronics for embedded automotive applications, requiring high stability under temperature variations. However, critical issues occurring at nanoscale needs further material studies concerning the role of interfaces (nitride, dielectrics, etc..), the alloy composition (phase separation, precipitation, segregation, etc..), the effect of doping alloy elements and the impact of such issues on the crystallization kinetics (nucleation and growth).
This work aims to closely study the optimized chalcogenides integrated in STMicrolectronics memory cells by atom probe tomography (APT). To this aim, a large part of the work will be dedicated to the development of original sample preparation methods using focus ion beam (FIB) in order to perform APT measurements from full sheet layers up to more complex memory structures.
This work will be performed in strong partnership with STMicroelectronics.
1 P. Noé, C. Vallée, F. Hippert, F. Fillot, and J.-Y. Raty, Semicond. Sci. Technol. 33, 13002 (2018).
2 M. Le Gallo and A. Sebastian, J. Phys. D Appl. Phys. D 53, 213002 (2020).
3 B. Tallis, Intel Announc. Optane Mem. M15 3D XPoint M.2 PCIe 3.0 X4 Https//Www.Anandtech.Com/Show/14437/Intel-Announces-Optane-Memory-M15-3d-Xpoint-on-M2-Pcie-30-X4 (2019).
4 S. Menzel, U. Böttger, M. Wimmer, and M. Salinga, Adv. Funct. Mater. 25, 6306 (2015).
5 M. Wuttig and N. Yamada, Nat. Mater. 6, 824 (2007).
6 M. Putero, M.-V. Coulet, C. Muller, C. Baethz, S. Raoux, and H.-Y. Cheng, Appl. Phys. Lett. 108, 101909 (2016).
The ideal candidate holds a PhD degree in Material Sciences (or equivalent), has a solid practice of sample preparation by focus Ion Beam (for APT or TEM), a background in physics, good communication skills and is proficient in written and spoken English. Knowledge of magnetron sputtering, X-Ray Diffraction, and PCM will be appreciated.
Starting date: sept. 2020 / Laboratory: IM2NP (http://www.im2np.fr/)
Industry: STMicroelectronics, Crolles– France (http://www.st.com)
Duration : 1 year. / Location: IM2NP-Marseille
Applications including a CV, two letters of recommendation and a letter of motivation should be sent by email to Dr. Magali PUTERO (firstname.lastname@example.org) and Dr. Alain PORTAVOCE (email@example.com)Continue reading
|Title||Postdoc position - Atom Probe Tomography analyses of Phase-Change Materials in Advanced Embedded Memory|
|Employer||Institut Matériaux Microélectronique Nanosciences de Provence (IM2NP)|
|Job location||Faculté des Sciences de Saint Jérôme - Case 142, Avenue Escadrille Normandie Niemen, F-13397 Marseille Cedex 20, 13397 Marseille|
|Published||July 21, 2020|
|Job types||Postdoc  |
|Fields||Materials Engineering,   Engineering Physics,   Atomic, Molecular and Optical Physics,   Materials Physics,   Electronics  |