IM2NP
Goals: STMicroelectronics (Crolles and Rousset sites) are developing advanced RF technologies
that are crucial for future mobile networks and internet. These new microelectronic devices are
produced in a 65 nm technological node on 200 mm wafers, i.e. the dimension of the gate size
of CMOS transistors (for Complementary Metal Oxide Semiconductor). The adaptation of advanced
radiofrequency microelectronic devices for 200 mm factories requires a new generation of cobalt
silicide, necessary to connect them with their environments. In the semiconductor industry, the
cobalt disilicide, with the chemical formula CoSi2, is generally not used for the 65 nm technological
nodes because it is not able to be formed in small dimensions. This is related to the sequence of
formation of the different solid phases necessary to obtain a thin layer of CoSi2 on the top of CMOS
devices. Different solutions have already been proposed or tested. The objective of the
collaboration between STMicroelectronics and IM2NP is to propose innovative approaches to
demonstrate the feasibility of integrating a high–performance cobalt silicide for 65 nm
industrial processes in 200 mm factories. During these 2 postdoctoral years, the following
studies will be addressed: 1) influence of the pre–amorphization processes Ar, As, Ge, and C on the
resistivity, texture, and grain size of Co silicide; 2) impact of alloying elements including Ni as well
as deposition processes (temperature, thickness) on the properties of Co silicide; 3) beneficial
effects of disruptive approaches such as intermediate layers, deposited between the Co and Si as
well as new anneals. A particular attention will be paid to the systematic studies of the grains size of
the silicide (SEM, TEM, ASTAR), their texture (ex–situ XRD, SEM/EBSD/TKD, TEM/ASTAR), their
composition (EDX, APT) and their phase sequence (in–situ XRD, in–situ Rs…). Modeling and
simulation will also be performed to reveal the mechanisms of silicide formation.
The postdoctoral will take place at the IM2NP laboratory in Marseille (Campus Saint Jérôme) which
will provide a large scope of characterization equipments such as tomographic atom probe (APT),
scanning (SEM/EBSD/TKD) and transmission electron microscopy (TEM/ASTAR), X–ray
characterizations, and resistivity measurements. The samples will be made at ST Crolles, ST
Rousset or at IM2NP where the postdoctoral will use the techniques of vacuum deposition,
annealing, as well as the previously detailed various characterization techniques. The collaboration
between STMicrolectronics and IM2NP on silicides is well established with several PhD students
(CIFRE), and has led to several publications and conference presentations.
Collaboration between:
– IM2NP (Marseille): a multidisciplinary research institute that links fundamental research to
applications in the key domains of materials, microelectronics and nanosciences
– STMicroelectronics (Crolles and Rousset): a world leader in the microelectronic components
market that develops, manufactures and markets high–tech chips
Duration : 2 years
Starting date : 2023
Net salary: 2000–2500 €/month depending on experience