Copper-graphene heterostructure for back-end-of-line compatible high-performance interconnects

Abstract

Here, we demonstrate the fabrication of a Cu-graphene heterostructure interconnect by the direct synthesis of graphene on a Cu interconnect with an enhanced performance. Multilayer graphene films were synthesized on Cu interconnect patterns using a liquid benzene or pyridine source at 400 °C by atmospheric pressure chemical vapor deposition (APCVD). The graphene-capped Cu interconnects showed lower resistivity, higher breakdown current density, and improved reliability compared with those of pure Cu interconnects. In addition, an increase in the carrier density of graphene by doping drastically enhanced the reliability of the graphene-capped interconnect with a mean time to failure of >106 s at 100 °C under a continuous DC stress of 3 MA cm−2. Furthermore, the graphene-capped Cu heterostructure exhibited enhanced electrical properties and reliability even if it was a damascene-patterned structure, which indicates compatibility with practical applications such as next-generation interconnect materials in CMOS back-end-of-line (BEOL).

Flexible Copper Nanowire Electronics for Wireless Dynamic Pressure Sensing

“…The preeminent requirements for any metal conductor to reliably function at high temperatures involve oxidation resistance to the exposed environment, without significantly affecting its physical properties, and hence, there arises a need for a multimaterial component that satisfies the mechanical requirements as well as provide a modicum of environmental resistance. Graphene is physically and chemically compatible with the base material (copper nanowires) and can be obtained via an in situ conversion process. , To enable high strain rate impact sensing, we select a hybridized copper–graphene (Cu-G) nanowire conductor because of the combined advantages of copper’s high electrical conductivity and graphene’s high thermal conductivity, deeming it suitable for high-temperature applications. The inset of Figure b shows the SEM image of the Cu-G printed features on flexible yttria-stabilized zirconia substrate.…”

“…Graphene is physically and chemically compatible with the base material (copper nanowires) and can be obtained via an in situ conversion process. 37,38 To enable high strain rate impact sensing, we select a hybridized copper−graphene (Cu-G) nanowire conductor because of the combined advantages of copper's high electrical conductivity and graphene's high thermal conductivity, deeming it suitable for high-temperature applications. The inset of Figure 4b shows the SEM image of the Cu-G printed features on flexible yttria-stabilized zirconia substrate.…”

The heat equation for nanoconstrictions in 2D materials with Joule self-heating

“…and L H = √ κ 0 R B . As previously, we consider the reduced temperature t(r) normalised by T J,rect , equation (7). As this is a nonlinear equation, the potential difference (or current) appears via the additional parameter χ which describes the level of Joule heating as compared to room temperature.…”

“…There is huge interest in the thermal properties of twodimensional (2D) materials, motivated by applications to thermal management [1][2][3][4], interconnects in integrated circuits [5][6][7], thermoelectric devices [8][9][10][11] and nanoscale fabrication [12][13][14][15]. While nanoscale constrictions are of great importance for their electrical transport characteristics, particularly in the quantum regime [16,17], they also promote enhanced Joule self-heating and thermoelectric coefficients [18][19][20][21].…”

“…The maximum temperature T(0) − T 0 as function of the minimum width w for L H = 0.2L where diamond symbols show numerical data from the finite element method solution[54] of the two-dimensional equation (4). The plots are normalized by the Joule temperature for a rectangle T J,rect , equation(7). The first row (a), (b) is for a nanowire of length ℓ = 0.5L, and the dashed and solid lines show the temperature found from the one-dimensional equations (15) and(16), respectively.…”