Enabling Simultaneous Extreme Ultra Low-k in Stiff, Resilient, and Thermally Stable Nano-Architected Materials

Abstract

(GIST), Gwangju 61005, Korea † These authors have contributed equally to this work.Keywords: dielectric constant, low-k, nanolattice, porosity, Young's modulus. AbstractLow dielectric constant (low-k) materials have gained increasing popularity because of their critical role in developing faster, smaller, and higher performance devices. Their practical 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 2 use has been limited by the strong coupling between mechanical, thermal, and electrical properties of materials and their dielectric constant; low-k is usually attained by materials that are very porous, which results in high compliance, i.e. silica aerogels, 39 high dielectric loss, i.e.porous polycrystalline alumina, 25 and poor thermal stability, i.e. Sr-based metal-organic frameworks. 23 We report the fabrication of 3D nano-architected hollow-beam alumina dielectrics whose k is 1.06-1.10 at 1MHz that is stable over the voltage range of -20V to 20V and a frequency range of 100 kHz to 10 MHz. This dielectric material can be used in capacitors and is mechanically resilient, with a Young's modulus of 30 MPa, a yield strength of 1.07 MPa, a nearly full shape recoverability to its original size after >50% compressions, and outstanding thermal stability with a thermal coefficient of dielectric constant (TCK) of 2.43 × 10 -5 K -1 up to 800 °C. These results suggest that nano-architected materials may serve as viable candidates for ultra low-k materials that are simultaneously mechanically-resilient, and thermally and electrically stable for microelectronics and devices. Main TextDesigning and synthesizing low dielectric constant (low-k) materials has been a subject of intense research because of their potential use in high performance technological applications like computer processing, 1,2 wireless communications, [3][4][5][6] and automotive radar. 7 Lowering the k of the interlayer dielectric decreases the resistance-capacitance (RC) delay, lowers power consumption, and reduces cross-talk between nearby interconnects, all of which pose significant issues for modern integrated circuits (ICs). [8][9][10] The low-k property is also favored in low temperature co-fired ceramic (LTCC) technology and represents the backbone of Multi Chip Module (MCM) technology, which enables the integration of passive elements like inductors, 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 3 resistors, and capacitors, which serve as building blocks for 3D circuits for the microwave/millimeter communications industry. [11][12] For example, the antenna in a typical RF module for radiating/receiving radio waves, requires the supporting substrate whose k is sufficiently low to preven...

Additive Manufacturing of Nano- and Microarchitected Materials

“…12 Utilizing this emergence of new functionality at the nanoscale and proliferating these "size effects" onto 3D architectures have already proven successful; one notable example is the demonstration that hollow nanolattices with relative densities of ∼0.1%, made of 10 nm thick brittle ceramic, recovered after compression in excess of 50% without sacrifice in strength or stiffness 13,14 and had an exceptionally low dielectric constant of 1.06 at 1 MHz. 15 Similar exceptional recoverability was also found in nanoarchitectures made of metallic glasses, materials that are notorious for catastrophic failure via rapid shear band initiation and propagation. 16 Another example is amorphous carbon nanolattices whose compressive strength approaches the ideal material strength.…”

Creation of Centimeter‐Sized 2 D Crystalline Film by Crystallization of Homopolymer in Solution

“…[16,17] The detailed mechanism of such al ow dielectric constant needs furtherstudy.This low dielectric constantleads to its potentiala pplications in ultra-large-scale integrated circuit devices because decreasing parasitic capacitance is crucial for high qualified integrated circuit devices. [16,18] From the FET device, the transfer curve (Figure 6c)a nd output curves (Figure S16, Supporting Information) demonstrate that the carrier concentration in the film increases upon decreasing the gate voltage from 60 Vt oÀ60 V. The hole mobility of this film is 2.1 10 À3 cm 2 V À1 s À1 ,w hich is three orders of magnitude larger than those of recently reported 2D conjugated polymers (2DCP) such as porphyrin (PP)-contained 2DCP (1.3 10 À6 cm 2 V À1 s À1 ) [2b] and benzodithiophene (BDT)-contained 2DCP (3.0 10 À6 cm 2 V À1 s À1 ) [19] (Figure 6d).…”

Hyperbranched‐polysiloxane‐based hyperbranched polyimide films with low dielectric permittivity and high mechanical and thermal properties

“…synthesized perfluorocyclobutyl biphenyl ether‐based PI, which showed low D k (2.43−2.50) upon moisture absorption for 24 h. However, this kind of PI suffers from poor adhesion with metal. Because the D k of air is approximately 1.0, introducing air voids into PI will decrease the dielectric permittivity of PI . These PIs, such as nanoporous PI and PI aerogels, have been extensively studied .…”

“…Because the D k of air is approximately 1.0, introducing air voids into PI will decrease the dielectric permittivity of PI. 14,[20][21][22][23] These PIs, such as nanoporous PI and PI aerogels, have been extensively studied. 20,[24][25][26] The lowest D k (1.084) of porous PI was reported by Meador et al 27 However, porous PI often exhibits poor mechanical properties, which limit its wide application in some highly demanding aspects.…”