Damascene integration of copper and ultra-low-k xerogel for high performance interconnects

Abstract

MS 3702, Dallas, Texas 75265, (972) 995-5261Copper has been integrated with ultra-low dielectric constant (k) xerogel in a damascene architecture for the first time. For high performance microelectronics, the lowest delay interconnect system will require both a low resistivity conductor and a low-k dielectric. Copper, with a bulk resistivity of 1.7 pohm-cm, and xerogel, with a tunable dielectric constant of 1.3-3.0, provide the near ultimate in materials properties.Porous silica xerogel has several characteristics that make it an attractive interlayer dielectric (ILD). Because it is composed of a highly porous network of S O z , xerogel has high thermal stability and a low thermal expansion coefficient [1,2]. It can be produced with a wide range of dielectric constants by tuning the porosity in the deposition process, Figure 1. The porosity also controls the mechanical properties of the xerogel, and thus, can be optimized for damascene processing. Xerogel with a

Low‐kMaterials: Recent Advances

“…Nevertheless, two potential pathways have been explored. The first pathway interposes a thin, continuous layer between the porous ILD and the barrier metal [90,91]. This material could be deposited by various means and both organic and inorganic candidates have been proposed [25,48,49,[92][93][94][95].…”

Design and modeling of equipment used in electrochemical processes for microelectronics

“…Copper damascene interconnects have been utilized in the semiconductor industry since the mid-1990s [28][29][30]. In this application, trenches and vias are etched into a dielectric to define intralevel and interlevel interconnections.…”

High-performance interconnects: an integration overview

“…Relative permittivities of less than 2.5 are generally achieved by the introduction of porosity, which further reduces mechanical strength and (for the predominant open pore systems) may increase moisture/chemical adsorption as well. While early demonstration of copper and porous low-integration provides encouragement [22], co-optimization of material, process and integration architecture will be necessary for successful manufacturing implementation.…”