Home > Press > NEC and NEC Electronics develop new full low-k-Cu interconnect structure
Interconnect achieves significant reduction in active power consumption in LSI Devices
NEC and NEC Electronics develop new full low-k-Cu interconnect structure
Tokyo, Japan | Posted on December 13th, 2007
NEC Corporation and NEC Electronics Corporation have developed a new Silica-Carbon Composite (SCC) film capable of blocking Cu-atom diffusion into the dielectric films of LSI interconnects. Use of the SCC film establishes an ultimate full-low-k (FLK) Cu interconnect structure that realizes a reduction in active power consumption in LSI interconnects. The successful development of this FLK Cu interconnect can be attributed to extensive research and development on molecular nanotechnology manipulating the molecular structure and novel plasma-enhanced deposition technology.
Main features of the newly developed FLK interconnect
(1) The new low-k barrier dielectric SCC film has been developed based on molecular nanotechnology, which has a composite structure of unsaturated C=C molecular bonds and the conventional silica backbone structure to prevent Cu diffusion into the interlayer dielectric (ILD) films. The dielectric constant (k) was decreased to 35% that of conventional barrier dielectrics.
(2) A special stabilization process of the Cu metal surface proved that the SCC film capping the Cu lines maintained excellent insulation reliability, even after reducing the film thickness down to several tens of a nanometer.
(3) All of the parts of the insulating film in the FLK Cu interconnect consisted of low-k films, of which robust Molecular-Pore-Stack (MPS) low-k film (1) with stable sub-nanometer-sized pores was deposited continuously on the SCC film on top of the underlying Cu lines (2).
(4) Parasitic capacitance as a source of active power consumption in the LSI interconnects was reduced by 11% as compared to the reference low-k Cu interconnects without SCC film, and reliability was improved.
The newly developed FLK Cu interconnect has an ultimate structure making it applicable not only to leading-edge 32nm-node CMOS devices, but also to all kinds of conventional CMOS devices to realize low power consumption and high reliability. CMOS LSI devices with FLK Cu interconnects are expected to realize high performance IT/network equipment with very low power consumption, such as broadband wireless terminal devices, high speed and multi-task servers and low power microcomputers for automobile applications.
As a result of device scaling, a rapid increase in parasitic capacitance among closely-spaced multilayer interconnects induces undesirable active power consumption. Therefore, a solution to suppress parasitic capacitance has been long sought after. LSI multi-level Cu interconnects are isolated by two kinds of dielectric film, such as the interlayer dielectric (ILD) films isolating the Cu lines themselves and the barrier dielectric films that directly cover the Cu lines to prevent diffusion of Cu atoms into the ILD films. Extensive research and development has been carried out to establish low-k ILD films such as porous materials. However, it has been difficult for barrier dielectrics to fulfill both the requirements of low k-value and perfect blocking properties because the latter property is usually diminished by reducing the k-value or essentially the film density.
The newly-developed low-k SCC film blocks migration of the Cu atoms, where its blocking mechanism is likely to be the capture of Cu atoms by the unsaturated carbon bonds in the SCC film. The FLK Cu interconnect features a seamless stack of MPS ILD film and SCC barrier dielectrics on the Cu lines, which are desired for low power and high speed signal processing in ubiquitous-network applications. NEC and NEC Electronics will continue research and development toward early commercialization of LSI products with FLK Cu interconnects.
A part of this research was supported by the New Energy and Industrial Technology Development Organization (NEDO) under the MIRAI project (3). The research was presented on December 12 at the International Electron Device Meeting (IEDM) being held in Washington DC.
About NEC Corporation
NEC Corporation is one of the world's leading providers of Internet, broadband network and enterprise business solutions dedicated to meeting the specialized needs of its diverse and global base of customers. NEC delivers tailored solutions in the key fields of computer, networking and electron devices, by integrating its technical strengths in IT and Networks, and by providing advanced semiconductor solutions through NEC Electronics Corporation. The NEC Group employs more than 150,000 people worldwide. For additional information, please visit the NEC home page at: www.nec.com
About NEC Electronics
NEC Electronics Corporation (TSE: 6723) specializes in semiconductor products encompassing advanced technology solutions for the high-end computing and broadband networking markets, system solutions for the mobile handset, PC peripherals, automotive and digital consumer markets, and platform solutions for a wide range of customer applications. NEC Electronics Corporation has 25 subsidiaries worldwide including NEC Electronics America, Inc. (www.am.necel.com) and NEC Electronics (Europe) GmbH (www.eu.necel.com). For additional information about NEC Electronics worldwide, visit www.necel.com.
For more information, please click here
Copyright © NEC
If you have a comment, please Contact
Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.
Dartmouth researchers create 'green' process to reduce molecular switching waste December 15th, 2014
New technique allows low-cost creation of 3-D nanostructures December 8th, 2014
Researchers discern the shapes of high-order Brownian motions November 17th, 2014
Manipulating complex molecules by hand: New method in scanning probe microscopy: Jülich researchers create a word using 47 molecules November 6th, 2014
Instant-start computers possible with new breakthrough December 19th, 2014
Switching to spintronics: Berkeley Lab reports on electric field switching of ferromagnetism at room temp December 17th, 2014
Pb islands in a sea of graphene magnetise the material of the future December 16th, 2014
Stanford team combines logic, memory to build a 'high-rise' chip: Today circuit cards are laid out like single-story towns; Futuristic architecture builds layers of logic and memory into skyscraper chips that would be smaller, faster, cheaper -- and taller December 15th, 2014
Stacking two-dimensional materials may lower cost of semiconductor devices December 11th, 2014
Defects are perfect in laser-induced graphene: Rice University lab discovers simple way to make material for energy storage, electronics December 10th, 2014
Nanoscale resistors for quantum devices: The electrical characteristics of new thin-film chromium oxide resistors that can be tuned by controlling the oxygen content detailed in the 'Journal of Applied Physics' December 9th, 2014
'Giant' charge density disturbances discovered in nanomaterials: Juelich researchers amplify Friedel oscillations in thin metallic films November 26th, 2014
Scientists reveal breakthrough in optical fiber communications December 21st, 2014
Atom-thick CCD could capture images: Rice University scientists develop two-dimensional, light-sensitive material December 20th, 2014
Oregon researchers glimpse pathway of sunlight to electricity: Collaboration with Lund University uses modified UO spectroscopy equipment to study 'maze' of connections in photoactive quantum dots December 19th, 2014
Instant-start computers possible with new breakthrough December 19th, 2014