EDA Startup Addresses Litho Issues at 45nm

By Ann Steffora Mutschler -- Electronic News, 9/19/2006

To address a number of specific lithography challenges that must be solved for robust manufacturability at 45nm and below, San Jose-based Invarium Inc. rolled out this week its Dimension45/32 tool aimed at helping lithography and photomask synthesis teams to select and optimize the right combination of exposure strategies and full-chip photomask layout synthesis.

The tool can be used with layout retargeting if necessary to achieve the best post-etch results on silicon, with the largest process window and best yield, the company said.

Dr. Apo Sezginer, CTO at Invarium explained that the tool brings an added focus on solving problems, in addition to tool features and functions, to allow for fast and cost-effective patterning of designs, as well as get to volume production.

An important goal of Dimension45/32 is also the enablement of future patterning solutions at the 32nm node, he added.

A unique capability of Dimension45/32 is the ability to pattern critical routing layers at 45nm using dry lithography instead of immersion.

At the 45nm node, immersion lithography is generally considered necessary for front-end layers such as diffusion, gate poly and contact but the approach to be taken for metal routing layers M2 to M6 or beyond is less obvious. Cost considerations as well as the availability of a sufficient number of immersion tools make an all-immersion solution at 45 nm questionable and expensive, the company explained.

Since at 45 nm, it is no longer sufficient to just supply RET/OPC tools with general capabilities to customers, Dimension45/32, with the right combination of RET features, illumination and polarization techniques, can use a dry litho process to deliver a large process window and sufficient stability against process variations for all critical routing layers, Invarium noted.

Included in Dimension45/32 are the full capabilities of the company’s DimensionPPC tool, as well as a number of additional capabilities specifically geared to the 45 and 32nm nodes.

Further, the tool allows for process setup optimization, printability analysis, dynamic retargeting, enhanced etch models, enhanced process window optimization, model-based sub-resolution assist features (SRAF) and yield- based optimization.

The tool is currently being customer-qualified in North America, with a second customer qualification program to begin shortly in Asia.

Invarium is showing Dimension45/32 at the BACUS/SPIE Photomask Technology event being held this week in Monterey, Calif.