Low Loss Photodielectric Materials for 5G HS/HF Applications

Abstract

Abstract Fifth generation network technology, often referred to as 5G, holds great potential for higher communication speeds, higher data transmission rates and improved connectivity, however, current dielectric materials lack sufficiently low dielectric loss (Df) at desired form factors for next-generation devices. While photoimageable dielectrics will certainly play a role in 5G manufacturing, many of the chemistries that have evolved and are suitable for photodielectrics (aqueous developed and polar solvent developed materials) have a Df that is too high for a 5G devices. Arylalkyl thermoset polymers (ATPs) have long been known for its low dielectric properties and found use in many high frequency applications, especially GaAs devices. An existing ATP photodielectric, CYCLOTENE™ 4000 Series Dielectric is characterized and compared to a newly designed experimental platform herein called 5G-XP-1. The platform developed utilizes new monomer and polymer chemistry to deliver a system capable of low temperature cure within 1 hour between 170–200°C, self-priming adhesion on silicon, copper, silicon nitride and polyimide and low Df at high frequency in a full formulation (<0.005 20–40GHz). 5G-XP-1 is deposited as a spin on photodielectric material but is still capable of achieving a variety of final film thicknesses from 15–25 μm. More importantly the formulation can achieve high aspect ratio imaging with 1:1 AR vias using an i-Line Karl Süss Mask Aligner. Moreover, this photodielectric material can be developed using environmentally-friendly solvents, such as esters like propylene glycol monomethyl ether acetate (PGMEA). The new experimental material 5G-XP-1 spin on photodielectric material demonstrates considerable promise for next-generation 5G devices, with future improvements on mechanical properties already in progress.