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New Product: New RET technique turns lithography inside out |
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Oct 03, 2005 at 05:55 PM |
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Product Briefing
Outline:
Luminescent Technologies, has launched its "Inverse Lithography
Technology" (ILT) platform -- a completely new methodology for Resolution
Enhancement Technology (RET) software. Luminescent's first product is called
"Explorer," which combines sophisticated software and hardware to provide
complete ILT capability for small blocks ILT enables improved pattern fidelity,
expanded lithography process windows and reduced mask preparation cycle time,
according to the company. In an inverse approach to RET/OPC generation the new
technology first evaluates the desired on-wafer pattern and then mathematically
determines the mask features needed to produce the intended silicon outcome.
Wafer results from multiple semiconductor manufacturers have successfully
proven ILT's superior capabilities at 90nm, 65nm and 45nm nodes, according to
the company.
Problem:
Existing resolution enhancement techniques are reaching their practical
limits. Integrated circuit (IC) manufacturers are seeking alternatives to
overcome the challenges of smaller process windows, higher mask costs and
reduced yields, without changing today's design flow and lithography
infrastructure. Lithography-related design constraints must be relieved and
pattern fidelity must improve, while the unacceptable number of mask re-spins
must be reduced or eliminated. Current RET software slows lithography yield
ramps and negatively impacts time-to-market of today's ICs. The most common RET
software creates mask designs by moving design edges to approximate the
intended on-wafer result. Requiring multiple iterations, this ad hoc technique
is time consuming, labor intensive (extensive scriptwriting and verification)
and fundamentally unreliable. Several mask file re-spins typically occur before
chipmakers can confidently commit a design to mask and silicon.
Solution: Luminescent's
Explorer starts with the desired on-wafer result and reduces the
photolithography process to a series of mathematical equations. By solving the
equations, the on-wafer result is inverted to determine the optimal mask
patterns needed to produce the desired outcome. Since ILT analyzes the entire
image and not just the design edges, it
generates a globally optimized mask design in a single pass that is pre-
verified and correct by construction. By its nature, inversion is pattern-
independent and can be applied off-the-shelf to any design, thereby eliminating
the need for extensive scriptwriting that burdens existing RET software.
Applications:
Photomasks
Platform: Explorer
creates masks that print well at nominal exposure/defocus and at multiple
additional exposure/defocus anchor points. An intuitive topology-based
specification of wafer image quality provides superior ease of use for
lithographers. Featuring comprehensive process window analysis, the product has
a simple interface for illumination optimization and lithographic exploration.
It also includes integrated mask compliance features and a selectable e-beam or
laser mask output format.
Availability:
October 2005 onwards
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Lithography 
