Nanoimprint Lithography (NIL) has been shown to be an effective technique for replication of nano-scale features.
Jet and Flash Imprint Lithography* (J-FIL*) involves the field-by-field deposition and exposure of a low viscosity resist
deposited by jetting technology onto the substrate. The patterned mask is lowered into the fluid which then quickly flows
into the relief patterns in the mask by capillary action. Following this filling step, the resist is crosslinked under UV
radiation, and then the mask is removed, leaving a patterned resist on the substrate.
There are many criteria that determine whether a particular technology is ready for high volume semiconductor
manufacturing. Included on the list are overlay, throughput and defectivity.
Imprint lithography, like any lithographic approach requires that defect mechanisms be identified and eliminated in
order to consistently yield a device. NIL has defect mechanisms unique to the technology, and they include liquid phase
defects, solid phase defects and particle related defects. Especially more troublesome are hard particles on either the
mask or wafer surface. Hard particles run the chance of creating a permanent defect in the mask, which cannot be
corrected through a mask cleaning process. If Cost of Ownership (CoO) requirements are to be met, it is critical to
minimize particle formation and extend mask life.
To meet the CoO requirements, mask life must meet or exceed 1000 wafers. If, we make the conservative assumption
that every particles causes damage to the mask pattern, the number of particle adders must be less than 0.001 pieces per
wafer pass in the NIL tool. Therefore, aggressive strategies are needed to reduce particles in the tool.
In this paper, we will report on the techniques required to meet this condition and will describe how the particle
reduction techniques can be extended to our FPA-1200NZ2C system.
Imprint lithography has been shown to be an effective technique for replication of nano-scale features. Jet and Flash
Imprint Lithography* (J-FIL*) involves the field-by-field deposition and exposure of a low viscosity resist deposited by
jetting technology onto the substrate. The patterned mask is lowered into the fluid which then quickly flows into the
relief patterns in the mask by capillary action. Following this filling step, the resist is crosslinked under UV radiation,
and then the mask is removed, leaving a patterned resist on the substrate.
There are many criteria that determine whether a particular technology is ready for wafer manufacturing. For
imprint lithography, recent attention has been given to the areas of overlay, throughput, defectivity, and mask replication.
This paper reviews progress in these critical areas. Recent demonstrations have proven that mix and match overlay of
less than 5nm can achieved. Further reductions require a higher order correction system. Modeling and experimental
data are presented which provide a path towards reducing the overlay errors to less than 3nm. Throughput is mainly
impacted by the fill time of the relief images on the mask. Improvement in resist materials provides a solution that
allows 15 wafers per hour per station, or a tool throughput of 60 wafers per hour. Defectivity and mask life play a
significant role relative to meeting the cost of ownership (CoO) requirements in the production of semiconductor devices.
Hard particles on a wafer or mask create the possibility of inducing a permanent defect on the mask that can impact
device yield and mask life. By using material methods to reduce particle shedding and by introducing an air curtain
system, the lifetime of both the master mask and the replica mask can be extended. In this work, we report results that
demonstrate a path towards achieving mask lifetimes of better than 1000 wafers.
Finally, on the mask side, a new replication tool, the FPA-1100NR2 is introduced. Mask replication is required for
nanoimprint lithography (NIL), and criteria that are crucial to the success of a replication platform include both particle
control and IP accuracy. In particular, by improving the specifications on the mask chuck, residual errors of only 1nm
can be realized.
Imprint lithography has been shown to be an effective technique for replication of nano-scale features. Jet and Flash* Imprint Lithography (J-FIL*) involves the field-by-field deposition and exposure of a low viscosity resist deposited by jetting technology onto the substrate. The patterned mask is lowered into the fluid which then quickly flows into the relief patterns in the mask by capillary action. Following this filling step, the resist is crosslinked under UV radiation, and then the mask is removed, leaving a patterned resist on the substrate. Criteria specific to any lithographic process for the semiconductor industry include overlay, throughput and defectivity. The purpose of this paper is to describe the technology advancements made in the reduction of particle adders in an imprint tool and introduce the new mask replication tool that will enable the fabrication of replica masks with added residual image placement errors suitable for memory devices with half pitches smaller than 15nm. Hard particles on a wafer or mask create the possibility of creating a permanent defect on the mask that can impact device yield and mask life. By using material methods to reduce particle shedding and by introducing an air curtain system, test stand results demonstrate the potential for extending mask life to better than 1000 wafers. Additionally, a new replication tool, the FPA-1100 NR2 is introduced. Mask chuck flatness simulation results were also performed and demonstrate that residual image placement errors can be reduced to as little as 1nm.
Imprint lithography has been shown to be an effective technique for replication of nano-scale features. Jet and Flash* Imprint Lithography (J-FIL*) involves the field-by-field deposition and exposure of a low viscosity resist deposited by jetting technology onto the substrate. The patterned mask is lowered into the fluid which then quickly flows into the relief patterns in the mask by capillary action. Following this filling step, the resist is crosslinked under UV radiation, and then the mask is removed, leaving a patterned resist on the substrate. Criteria specific to any lithographic process for the semiconductor industry include overlay, throughput and defectivity. The purpose of this paper is to describe the technology advancements made overlay, throughput and defectivity and to introduce the FPA-1200NZ2C cluster system designed for high volume manufacturing of semiconductor devices. in the reduction of particle adders in an imprint tool and introduce the new mask replication tool that will enable the fabrication of replica masks with added residual image placement errors suitable for memory devices with half pitches smaller than 15nm. Overlay results better than 5nm 3sigma have been demonstrated. To further enhance overlay, wafer chucks with improved flatness have been implemented to reduce distortion at the wafer edge. To address higher order corrections, a two part solution is discussed. An array of piezo actuators can be applied to enable linear corrections. Additional reductions in distortion can then be addressed by the local heating of a wafer field. The NZ2C cluster platform for high volume manufacturing is also discussed. System development continues this year with a target for introduction later in 2016. The first application is likely to be NAND Flash memory, and eventual use for DRAM and logic devices as both overlay and defectivity improve.
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