Interface conductance modal analysis of a crystalline Si-amorphous SiO2 interface

Abstract

We studied the anharmonic modal contributions to heat transfer at the interface of crystalline Si and amorphous SiO2 using the recently proposed interface conductance modal analysis (ICMA) method. Our results show that ~74% of the thermal interface conductance (TIC) arises from the extended modes, which occupy more than ~58% of the entire population of vibrational modes in the system. More interestingly, although the population of purely localized and interfacial modes on the SiO2 side is less than 6 times the population of partially extended modes, the contribution to TIC by these localized modes is more than twice that of the contribution from partially extended modes. Such an observation, once again proves the nonnegligible role of localized modes to facilitate heat transfer across systems with broken symmetries, and reiterates the fact that neglecting the contribution of localized modes in any modal analysis approach is an over-simplification of the actual mechanisms of heat transfer. Correctly pinpointing the modal contributions is of vital importance, since these values are directly utilized in determining the temperature dependent TIC, which is crucial to silicon on insulator (SOI) technologies with myriad applications such as microelectronics and optoelectronics.

A Review of Experimental and Computational Advances in Thermal Boundary Conductance and Nanoscale Thermal Transport across Solid Interfaces

“…Their results show that localized modes at ≈33.3 THz that corresponds to SiO bond stretching exists in the Si side a few nanometers away from the interface even though these modes are nonexistent in the bulk Si. These results agree very well with MD calculations from Gordiz et al for the interface formed between crystalline Si and amorphous SiO 2 . Gordiz et al also show that even though these modes comprise less than 5% of the total modes in the system, they can contribute to more than 15% of the total interfacial conductance.…”

“…These results agree very well with MD calculations from Gordiz et al for the interface formed between crystalline Si and amorphous SiO 2 . Gordiz et al also show that even though these modes comprise less than 5% of the total modes in the system, they can contribute to more than 15% of the total interfacial conductance. All of these works point to the fact that localized modes at the interface can significantly alter the interfacial conductance and should not be ignored while considering thermal transport in systems with broken symmetries introduced via interfaces.…”

Applications and Impacts of Nanoscale Thermal Transport in Electronics Packaging

“…transmission functions from AMM, DMM, AGF, or phonon wave-packet method [71,257,[267][268][269][270][271][272][273]. Within the framework of MD methods, nonequilibrium MD (NEMD) [274][275][276] and interface conductance modal analysis [115,143,[277][278][279][280][281][282][283] are usually applied to predict h BD . The advantages of MD are that the anharmonic phonon scattering is included from the higher-order force constants of empirical interatomic potentials, and the interface structures are quite flexible, that complex interfacial details (like strong interfacial disorder and interfaces with dimensional mismatch) can be simulated.…”

The Role of Interface Vibrational Modes in Thermal Boundary Resistance

“…However, unlike previous studies of phonon trapping, on different systems, [ 13,14 ] this particular event seems to increase interface conductivity rather than decrease it, which for the c‐Si|a‐SiO 2 interface, is in good agreement with previous work. [ 9 ] Furthermore, we analyze which modes are present at both interfaces through a localization calculation, and compare those calculations with what we actually see happen during the simulations through a simple Fourier analysis. Finally, we calculate the Kapitza resistance for the c‐Si|c‐Ge and find very good agreement with previous studies.…”