Imprint Lithography

Imprint lithography represents a cost-effective and highly reliable means of transferring three-dimensional nano- or micro-scale patterns onto a wide variety of substrates.

For the imprint, a stamp is brought into contact with a photosensitive material on the substrate. The photoresist fills out the three-dimensional pattern of the stamp and then solidifies under UV light .  Parameters such as pattern topography, structure resolution and aspect ratio have a considerable influence on the process quality. 

Thanks to its compatibility to well-established semiconductor processes, imprint lithography plays a key role in the development and production of DFB lasers, HB LEDs, wafer-level cameras and MEMS. 

SUSS MicroTec solutions for imprint lithography are based on manual mask aligner platforms and support a wide range of materials and substrate with sizes up to 200 mm. Furthermore, SUSS platforms provide the capability of aligning and levelling stamps to substrates, as required by many imprint applications. Imprint equipment can also be retrofitted to SUSS mask aligners which are already in the field. 

Depending on process requirements, SUSS MicroTec offers different imprint technologies on its mask aligners:

UV-NIL: High-Resolution Nano-Imprinting

UV-NIL: High-Resolution Nano-Imprinting

Using UV-NIL (UV nano-imprint lithography) SUSS MicroTec offers a classic imprint process to transfer patterns having a resolution down to 50 nm with superior fidelity. The transfer of the patterns is achieved using a hard quartz glass stamp, which is brought into contact with a UV-sensitive photoresist on the substrate. This setup allows very precise control of process parameters such as pressure, process gap and duration. 

The UV-NIL method allows the highest resolution of the three SUSS MicroTec imprint processes and is recommended for all R&D setups due to ease of use. 

Highlights 

  • Resolution in the two-digit nanometer range (< 50 nm)
  • Control of process parameters using recipe editor
  • Simple to use
  • High homogeneity of resist residual layer thickness 

Mask Aligner Platforms with UV-NIL Technology

SCIL: Large-Area Nano-Imprinting

SCIL: Large-Area Nano-Imprinting

SCIL (substrate conformal imprint lithography) technology is particularly suitable for high demand imprint processes. Here a soft stamp is used in combination with a hard but flexible glass carrier, thereby achieving superior evenness of contact and exceptionally high fidelity in pattern transfer. 

Imprinting results from capillary forces rather than pressure so that any changes in structure are avoided during the contact process. Furthermore, the sequential contact routine  does not allow air gaps to form, which results in extremely high yields and increases productivity. 

As a result of its excellent structure replication and high uniformity, SCIL technology is suited for all highly demanding processes where a high-quality etching mask is employed, such as the production of optical elements and MEMS/NEMS as well as in the production of HB LEDs and VCELS. 

SCIL technology was developed in collaboration with Philips Research.

Highlights

  • Full-area imprint up to 200 mm
  • High resolution (< 70 nm)
  • High alignment accuracy (± 1 µm)
  • Long-life stamp

Mask Aligner Platforms with SCIL Technology

SMILE: Micro- and Nano-Imprinting

SMILE: Micro- and Nano-Imprinting

For the transfer of patterns in the micro- to nanometer range, SUSS MicroTec offers SMILE (SUSS MicroTec imprint lithography equipment) technology. 

There are two process variants, the use of which depends on the desired resolution.

  • For the imprinting of microstructures, the photosensitive polymer is deposited in the center of the substrate, from where it spreads radially to the outer edges, filling the stamp cavities. The exact positioning of the process gap is actively controlled via a closed feedback loop, allowing a residual layer thickness to be achieved with superior reliability.
  • To imprint nanostructures, a flexible stamp is used to contact the middle of a coated substrate and subsequently the contact is widened radially. 

The process allows very precise exposure of both micro- and nano-patterns, thereby offering a wide spectrum of potential applications and thus excellent process flexibility. SMILE is used for example in the production of MEMS and optical lenses for wafer-level-cameras. 

Highlights

  • Precise control over resist layer thickness and uniformity
  • Structures on both wafer sides are possible
  • Lens wafers stacking and UV bonding
  • High alignment accuracy (+/- 1 µm)
  • Edge handling or the application of buffer wafers to avoid active area contact
  • Handling of warped wafers

Mask Aligner Platforms with SMILE Technology

Downloads & Contact