The Evolution of Organosilicon Precursors for Low-k Interlayer Dielectric Fabrication Driven by Integration Challenges

Abstract

Since the application of silicon materials in electronic devices in the 1950s, microprocessors are continuously getting smaller, faster, smarter, and larger in data storage capacity. One important factor that makes progress possible is decreasing the dielectric constant of the insulating layer within the integrated circuit (IC). Nevertheless, the evolution of interlayer dielectrics (ILDs) is not driven by a single factor. At first, the objective was to reduce the dielectric constant (k). Reduction of the dielectric constant of a material can be accomplished by selecting chemical bonds with low polarizability and introducing porosity. Moving from silicon dioxide, silsesquioxane-based materials, and silica-based materials to porous silica materials, the industry has been able to reduce the ILDs’ dielectric constant from 4.5 to as low as 1.5. However, porous ILDs are mechanically weak, thermally unstable, and poorly compatible with other materials, which gives them the tendency to absorb chemicals, moisture, etc. All these features create many challenges for the integration of IC during the dual-damascene process, with plasma-induced damage (PID) being the most devastating one. Since the discovery of porous materials, the industry has shifted its focus from decreasing ILDs’ dielectric constant to overcoming these integration challenges. More supplementary precursors (such as Si-C-Si structured compounds), deposition processes (such as NH3 plasma treatment), and post porosity plasma protection treatment (P4) were invented to solve integration-related challenges. Herein, we present the evolution of interlayer dielectric materials driven by the following three aspects, classification of dielectric materials, deposition methods, and key issues encountered and solved during the integration phase. We aim to provide a brief overview of the development of low-k dielectric materials over the past few decades.

Thermo-curable and photo-patternable polysiloxanes and polycarbosiloxanes by a facile Piers–Rubinsztajn polycondensation and post-modification

“…[1][2][3] With the development of new packaging technologies, the industry urgently demands novel interlayer dielectric (ILD) materials with a low dielectric constant and loss, excellent thermal and dimensional stability, low moisture absorption and good adhesion to the substrate. [4][5][6] Various polymers have been proposed as potential alternatives to traditional inorganic ILDs due to their inherent low molecular polarity, abundant monomer optionality, adjustable functionalization and good processability, including polyimide, 7,8 polybenzoxazole, 9,10 and benzocyclobutene (BCB) resin. 11 Among them, BCB resin with excellent planarization ability, which can be cured free of the catalyst with no volatile compound emission, has shown great advantages in the multilayer wiring process of IC manufacture.…”

High‐Performance Low‐k Poly(dicyclopentadiene) Nanocomposites as Achieved via Reactive Blending with Norbornene‐Functionalized Larger POSS

“…Even so, the dielectric losses of PT n N n materials (<0.003) are as low as the reported advanced low-k materials. [8,10] To quantify the contribution of T n N n content and POSS size to the microstructures of PT n N n nanocomposites, positron annihilation lifetime spectrum (PALS) was emplyed because it was a powerful tool to characterize the free volume and closed-type sub-nanosized pores of materials through evaluating the annihilation time of injected positrons. After the injection of a fraction of positrons into materials, they will capture electrons and then annihilate from the para-state (p-Ps, singlet spin state) or the ortho-state (o-Ps, triplet spin state).…”

“…In recent years, polymer dielectrics with low dielectric constant (low-k, k < 2.5) and dielectric loss (<0.005) have attracted great DOI: 10.1002/mame.202300076 attention in the microelectronic industry and high frequency communication (e.g., the fifth-generation communication technology), because they not only efficaciously reduce the signal hysteresis time but also enhance the signal fidelity. [1][2][3][4][5][6][7][8] To meet the practical requirement, an ideal dielectric must possess excellent mechanical performance, high thermal and dimensional stability, good processability, and hydrophobicity. Although the commercial polymer dielectrics such as epoxy resins (EP), polycarbonate (PC), polyamides (PI), liquid crystal polymers (LCP), and polyphenyl ether (PPE) display high thermostability and good mechanical property, their dielectric constants and dielectric losses are usually too high to meet the future applications.…”

Increasing porosity in hydrogen-bonded organic frameworks for low-κinterlayer dielectric

“…[3][4][5][6][7][8] Methods of reducing the dielectric constant of materials can be divided into two main methods: (1) reducing the density of materials by introducing a porous structure into the material; [9][10][11][12] (2) reducing the polarizability of materials, generally by introducing lower polarizability bonds. [13][14][15][16][17] Conventional applications in interlayer materials are inorganic materials and organic polymer-based low-κ materials. 18 As a representative low-κ dielectric, SiO 2 has an advantage in terms of stability, but has large polarizability due to its silicon chemical bond, making it difficult to further decrease its dielectric constant to lower than 1.5.…”