Lithography and Metrology

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Lithography and Metrology

• University of Wisconsin
• Center for Nanotechnology

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Electron Beam Lithography

• JEOL JBX-5D2-U EBEAM LITHOGRAPHY SYSTEM
• 14 year old Electron Beam Lithographer
• 50 KeV Electron Beam
• LaB 6 Current Source
• 2 MHz Pattern Generator
• Variable field size, 80 micron and 800 micron
• Low and high resolution modes
• 10mm working distance for high res mode
• No height map
• Current Range - 10 pA to 10 mA
• Beam Size 10 nm for small current.
• 125 mm (5) Stage Travel with l/120
  Interferometer
• Best Resolution - 50 nm nested lines in 150 nm
  resist,
• 25nm isolated lines in 100nm resist.
• Patterns generated from standard CAD formats.
• Control and pattern conversions done on VAX
  4106a computer with
• VMS operating system.
• Up to 5 masks, 4 wafers, various sizes of
  wafer pieces.

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E-beam Exposure Process

• CAD generation in .dxf, .dwg, .gds and conversion
  to .cif.
• Convert pattern to e-beam specific JEOL01 pattern
  format. It is then sent to the e-beam computer
  for conversion to JEOL51 binary format.
• Create job deck text file that dictates
  parameters of exposure, including pattern
  location and dose. Send to e-beam computer for
  conversion to e-beam language.
• Spin resist and load sample into e-beam chamber.
• Align e-beam gun, column, and apertures set
  desired beam current.
• Expose and develop.

Job file Example
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Results
26nm trenches in 75nm of PMMA.
Donut with 50nm trench in UV3
18nm trenches in 75nm of PMMA
300nm feature in 3microns of PMMA
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Binary X-ray Masks
Binary X-ray masks can be patterned in the E-beam
and used for multiple exposures on CNTechs X-ray
steppers. The masks consist of X-ray absorbing
gold features suspended on a thin silicon nitride
membrane.
The silicon nitride mask blank is coated with
photoresist and patterned using the e-beam.
Gold is then plated using liquid electrolysis
which fills In areas where resist was removed.
Those areas will mask X-rays on the final mask.
Silicon Nitride mask blank.
100nm gratings exposed in UV3
Final 100nm features in gold absorber
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Chrome on Glass Optical Masks
CNTech has the ability to manufacture etched
chrome on glass optical masks which can then be
used for exposures on most UV steppers. Features
can be made in the range of a half micron using
a liquid etch process.
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LEO 1550 VP FE-SEM
2nm layers imaged at 5kV
The LEO 1550VP is the ultimate combination of the
GEMINI ultra-high performance field emission
column, LEO's Variable Pressure technology, the
enhanced VPSE detector and the large fully
motorised Cartesian stage. Key Features
Ultra-high resolution in high vacuum over the
full accelerating voltage range - 1nm at 20kV,
2.1nm at 1kV Superior resolution in VP
mode, 2.0nm at 30kV Optimum secondary
electron imaging in all modes Unique
in-lens detector in high vacuum, enhanced VPSE
detection in VP mode Minimal specimen
preparation for imaging and X-ray analysis
Fully motorised Cartesian stage handles bulky
or irregular samples. Equally useful
for handling a large number of small samples or
standards for WDS Short analytical
working distance for simultaneous SE or BSD
imaging, EDS and WDS
analysis Fully automated vacuum system
with simple point and click selection of vacuum
pressure
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NPGS Lithography Package for the LEO
CNTech has a JC Nabity Nano Pattern Generation
System mounted on our LEO SEM. It uses both
hardware and software to interfaces with the SEM
and allow electron beam lithography by
controlling the SEMs own scan coils. The system
attains high resolution due to the extremely
small beam diameter achieved by the LEO SEMs
GEMINI column. Lithography can be done from a
low voltage of 100V up to the maximum range of
the LEO at 30kV. The system is Windows based
software and can accept a variety of CAD formats.
This leads to the system being very
user-friendly for those already well-versed in
the use of the LEO.
40nm features in 120nm of PMMA
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Thermo-Noran X-ray Microanalysis System
CNTech has a Thermo-Noran X-ray Microanalysis
System mounted on the LEO SEM that can be used
for elemental analysis of sample. The system
can do qualitative and quantitative sample
analysis and area mapping of elements.
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Thermo-Microscopes Autoprobe M5EScanning Probe
Microscope System
CNTech has a TM AFM that can be used for multiple
can modes including contact, non-contact,
thermal, lateral force, and phase imaging.
Roughness measurement on a grating