Abstract:
Using current techniques, GNR layers suffer from edge roughness during fabrication.
In addition, MLGNRs turn into graphite as number of GNR layers increase that further
degrades the performance of MLGNRs. This thesis aims toward higher performance
building in MLGNRs as compared to traditional and industry preferred interconnect
material i.e. Cu. Closed-form analytical models for transient analysis of MLGNRs are
proposed in this work. It is seen that accurate extraction of circuit parameters of
MLGNRs is extremely important. In that context, the analytical model for computation of
equivalent capacitance in MLGNRs interconnects is proposed by considering interlayer
coupling. In our analysis, it is observed that Fermi level, mean free path in GNR layers
and inter-layer resistivity between GNR layers significantly affect the performance of
MLGNRs.
This thesis proposes two approaches to improve the performance of MLGNRs. First is
the intercalation of metal and compounds in MLGNRs that leads to increase in Fermi
level in GNR layers and lowering in the inter-layer resistivity between GNR layers. Here,
AsF5 and Li have been used as intercalants. The thickness of intercalated MLGNR stack
is optimized to obtain best performance for interconnect applications. Based on our
analysis, we proposed optimized Li-intercalated MLGNR structures as potential
candidates to substitute Cu at local, intermediate and global level interconnect
applications. The optimized top-contact Li-intercalated MLGNRs with edge roughness
exhibit significantly lower energy-delay product and higher bandwidth density as
compared to Cu at all interconnect applications.
Our second approach is the insertion of high-k dielectric between GNR layers that
leads to higher mean free path in each GNR layers. This technique prevents the MLGNRs
from converting into graphite. An analytical model is proposed to compute scattering rate,
mean free path and mobility where dielectric is inserted between GNR layers. It is seen
that the transport properties of GNRs are strongly depend on the surrounding dielectric
environment and the quality of dielectric sample. Using cleaner samples, mean free path
higher than 1 𝜇𝑚 can be obtained.
