Sequential Infiltration Synthesis Advances Lithography (IN-10-017, 10-106)
A unique lithography resist transformation process that dramatically improves image quality while reducing cost.
Directed self-assembly (DSA) of block copolymers is targeted as a next-generation lithographic technique for ultra-high resolution patterning. SIS enables practical applications of DSA by dramatically improving both the etch resistance and differential etch resistance of block copolymer films.
Lithography is widely used for defining patterns with high spatial resolution. In most applications of this technique, a thin-film polymeric resist material coating the substrate is patterned using light, electrons, or self-assembly. This resist film defines the pattern to be etched into the substrate. For the resist to function properly, the masking portion of the resist must be able to withstand deep plasma etching of the substrate, even though the resist itself must be relatively thin to maintain high spatial resolution. Argonne’s new Sequential Infiltration Synthesis (SIS) process is uniquely able to meet both requirements by considerably increasing the etch resistance of the resist so that even a thin resist can permit the deep, high-aspect-ratio patterning of substrates. In a variation of the technique, SIS advances block copolymer (BCP) lithography by dramatically increasing the plasma etch contrast between the component blocks of a self-assembled polymer film, thereby permitting the massively parallel, high-resolution and low-cost patterning of substrate materials.Description
In SIS lithography, a patterned resist layer is placed in a chamber, where gas phase precursors, such as trimethylaluminum and water, penetrate the resist and react directly with it. This process infiltrates the bulk of the film with alumina or other inorganic materials, rendering the resist dramatically more resistant to plasma etching with no degradation to the pattern. Consequently, high-resolution polymer resists acquire the large etch resistances typically found in inorganic dielectric materials.
In SIS-enhanced BCP lithography, one phase of a self-assembled block copolymer thin film is selectively infiltrated with alumina or other materials, yielding an inorganic nanostructure mimicking the original block copolymer template that serves directly as a robust etch mask. The SIS-modified films are resistant to a variety of plasma etching chemistries enabling the direct patterning of a range of substrates without the need for intermediate hard mask layers. This method considerably simplifies the directed self-assembly (DSA) of nanostructures in technologically important materials over large areas with excellent transfer fidelity.
- SIS eliminates the need for an intermediate hard mask layer, which reduces cost and complexity.
- SIS preserves the quality of the printed pattern even in the case of deep, high-aspect-ratio nanostructures.
- The wide variety of resist/SIS precursor combinations makes the SIS process applicable to a broad range of resist and substrate materials.
- The low thermal budget of SIS makes it compatible with most microelectronic fabrication processes.
- Pattern collapse issues are overcome with SIS treatment because thinner resist films can be used.
- SIS-modified BCP films are resistant to a variety of plasma etch chemistries, enabling the direct nanoscale patterning of a range of substrates including silicon, indium tin oxide, and permalloy.
SIS application areas include microelectronics, optoelectronics, plasmonics, nanofluidics, high-density storage media, advanced sensors and catalysts, and x-ray optics.More Information
Using SIS, the etch resistance of photoresist, electron-beam resist, and block copolymer (DSA) resist have all been dramatically increased. These improvements came at no expense to the line-edge roughness of the lithographically defined patterns.
A variety of etch chemistries were used with the SIS-enhanced lithography process, enabling the direct nanoscale patterning of materials such as silicon, indium tin oxide, and permalloy.
The SIS technology is available for licensing.
Additionally, Argonne is seeking partners for further technology development and commercialization of SIS lithography.
U.S. Patent Application 13/209,190 (Published US 2012-0046421 A1) “Ordered nanoscale domains by infiltration of block copolymers”
U.S. Patent Application 13/427,619 (Published US 2012-0241411 A1) “Sequential infiltration synthesis for advanced lithography”
|Title and Abstract||
SEQUENTIAL INFILTRATION SYNTHESIS FOR ADVANCED LITHOGRAPHY
A plasma etch resist material modified by an inorganic protective component via sequential infiltration synthesis (SIS) and methods of preparing the modified resist material. The modified resist material is characterized by an improved resistance to a plasma etching or related process relative to the unmodified resist material, thereby allowing formation of patterned features into a substrate material, which may be high-aspect ratio features. The SIS process forms the protective component within the bulk resist material through a plurality of alternating exposures to gas phase precursors which infiltrate the resist material. The plasma etch resist material may be initially patterned using photolithography, electron-beam lithography or a block copolymer self-assembly process.
Ordered Nanoscale Domains by Infiltration of Block Copolymers
A method of preparing tunable inorganic patterned nanofeatures by infiltration of a block copolymer scaffold having a plurality of self-assembled periodic polymer microdomains. The method may be used sequential infiltration synthesis (SIS), related to atomic layer deposition (ALD). The method includes selecting a metal precursor that is configured to selectively react with the copolymer unit defining the microdomain but is substantially non-reactive with another polymer unit of the copolymer. A tunable inorganic features is selectively formed on the microdomain to form a hybrid organic/inorganic composite material of the metal precursor and a co-reactant. The organic component may be optionally removed to obtain an inorganic feature s with patterned nanostructures defined by the configuration of the microdomain.
|Technology ID||Development Stage||Availability||Published||Last Updated|
|ANL-IN-10-017, ANL-IN-10-106||Development - Proof-of-concept demonstrated at the laboratory level.||Available||12/13/2012||12/13/2012|