Highly porous interlayer dielectric for interconnect capacitance reduction

Abstract

Hydrogen silsesquioxane (HSQ) is a low density material for intra-metal gapfill, that offers low permittivity for interconnect capacitance reduction. Films with k as low as /spl sim/2.2 preferentially form between tightly-spaced metal leads when cured at low temperature (<400/spl deg/C), and interlayer dielectric properties are stable from 1 MHz to 1 GHz. HSQ simplifies the process integration of low-k materials for high performance interconnect applications by using standard semiconductor spin-on production techniques. Use of porous HSQ as a gapfill dielectric dramatically reduces the capacitive coupling between metal leads, resulting in higher interconnect performance.