AMO

Interference Lithography Gratings

ILInterference lithography is an optical nanolithography technology for the fabrication of extensive periodic nanostructures. Critical dimensions of less than 50 nm can be realized. At AMO two interference lithography tools are installed. One setup for extensive, high quality gratings with fixed periods, the other more flexible tool allows quick prototyping. We offer grating fabrication on silicon, silicon dioxide and other substrates with tailored pitch, etch depth and size.

Large area holographic gratings and diffractive optical elements

The exposure of wafers with a diameter up to 8″ (200 mm) requires a large optical table (2,5m x 4m), robust optical components and active fringe stabilization to compensate unavoidable vibration and noise causing phase modulation in the interferometer. AMO solved these problems and operates a 266 nm beam line with a fringe stabilization system based on a digital PID controller from AMOtronics.

Long lasting experience

For more than 15 years AMO has therefore developed and increased their product portfolio and successfully established several standard structures which are commercially available. Furthermore AMO offers prototyping solutions, e.g. for high efficient pulse compression gratings.

More details to every single above mentioned point can be found in the corresponding FactSheets “Interference Lithography” and “Nanogratings” in the sidebar on the right-hand side. The gratings available from stock are listed as well.

AMO’s product portfolio in interference lithography comprises the following:


Standard silicon gratings

  • large-area, coherent and stitching free gratings
  • high period fidelity as well as little phase distortion
  • rectangular edge profile due to the use of chemically reinforced DUV photoresists in combination with anisotropic RIE etching processes
  • in-house developed phase stabilization system enables the fabrication of high-contrast gratings
  • high flexibility for realizing any possible pattern is achieved by process optimized positive and negative resists
  • the use of an adapted BARC (bottom antireflective coating) minimizes the appearance of standing waves and hence enhances the structures’ dimensional accuracy
Substrate material Silicon (100)
Substrate thickness (500µm – 650µm) ± 50µm
Substrate dimensions 4”, 6”, 8” and every rectangular shape within
Type of grating lines, pillars, holes, moiré pattern
Period 150nm – 180nm, 250nm- 2500nm
Etch depth Up to 1000nm (depending on period and type of grating)
Active area depending on period and type of grating
P1040086Fully covered 4”, 6” and 8” wafer 030901250nm period, linear grating
m210604o450nm period, 2-D pillar-grating m020704m550nm period, 2-D pseudohex holes

Nanoimprint Masters + Templates

IL Master for Soft UV-NIL

  • Master for fabrication of PDMS- or polymer stamps
  • Stamps are compatible with Imprint tools MA8 by Suess as well as EV 620 by EV Group
  • Upon customer request the master can be modified by a teflon like anti sticking layer
Substrate material Silicon (100)
Substrate thickness (500µm – 650µm) ± 50µm
Substrate dimensions 4”, 6”, 8” and every rectangular shape within
Type of grating lines, pillars, holes, moiré pattern
Period 150nm – 180nm, 250nm- 2500nm
Etch depth up to 1000nm (depending on period and type of grating)
Active area depending on period and type of grating
M261101dMaster for plasmonic structures with 2 resonance frequencies AFMMaster for plasmonic structures with 2 resonance frequencies
m060902fMaster with pillar structures M050501AMaster with photonic crystal structures

 

IL Templates for Hard UV-NIL

Substrate material Fused silica
Substrate thickness 500µm – 6,35mm
Substrate dimensions up to 6“ @ 500µm thickness, 1-1.5“ @ 6,35mm thickness
Type of grating lines, pillars, holes, moiré pattern
Period 250nm- 2500nm
Etch depth up to 500nm (depending on period and type of grating)
Active area depending on period and type of grating
uv nil800nm pillar grid, 4“ SiO2 wafer SSMM2200nm linear grating, 1” SiO2 sample
Hard master600nm linear grating, 1,5“ SiO2

Customer specific gratings

Different dielectrics (SiO2, HfO2, Ta2O5) on silicon or fused silica with grating structure m020301aTa2O5 top layer with 580nm grating
Coating on top of grating for diffraction efficiency enhancement m051101_o300nm grating fused silica coated with 80nm Al
Antireflection structures for electroforming M140605eMoth eye structure
High aspect ratio gratings test2500nm pitch grating
Mix and match Interference lithography and electron beam lithography 40K_010MWaveguides in 500nm pillar grid
SiN spacer process for sub 10nm IL structures PROBE2H

Services

  • Patterned wafer defect inspection KLA 2139
  • SEM und AFM inspection
  • Characterization of absolute period by means of diffraction measurement