EUV lithography insertion is anticipated at the 7 nm node and below; however, defects added to the mask during use is a
lingering concern. Defectivity in the scanner is non-zero and an EUV pellicle membrane to protect the mask for high
volume manufacturing power levels does not yet exist. The EUV photons are strongly absorbed by all materials. Sibased
membranes leverage the low absorption coefficient k value (k = 0.0018 at 13.5 nm) for reasonable transmission,
but poly Si becomes fragile and wrinkles during the high temperatures associated with exposure. An alternate approach
to high transmission is deploying very thin or porous layers so that there are fewer atoms to absorb light. For example,
carbon nanomaterials have a reasonably low k value (k = 0.0069), but are strong enough to be fabricated in very thin
layers. Graphene, graphite, carbon-nanosheets and carbon nanotubes are all candidate carbon nanomaterials for this
application, but we focus here on carbon nanotubes (CNTs). Our first measurements on CNT films of ~60 nm thick were
found to have 96.5% transmission at 13.5 nm. Adding CNT layers also enhanced the strength of a thin SiN membrane
significantly. In this paper, critical pellicle metrics will be evaluated in more detail: EUV transmission, bulge test for
mechanical strength, emissivity measurements for heat management, and exposure testing in a hydrogen environment.
Recent research revealed that microactuators driven by pressurized fluids are able to generate high power and force
densities at microscale. Despite these promising properties, fluidic actuators are rare in microsystem technology. The
main technological barrier in the development of these actuators is the fabrication of powerful seals with low leakage.
This paper presents a seal technology for linear fluidic microactuators based on ferrofluids. An accurate design method
for these seals has been developed and validated by measurements on miniaturized actuator prototypes. Our current
actuator prototypes are able to seal pressures up to 16 bar without leakage. The actuator has an outside diameter of 2
mm, a length of 13 mm and the actuator is able to generate forces of 0.65 N and a stroke of 10 mm. Moreover, promising
properties such as the restoration of the seal after a pressure overload have been observed.
An important technological barrier in the development of microrobotic systems is the lack of compact sensor-actuator
systems. This paper presents a piston-cylinder fluidic microactuator with an integrated inductive position sensor. Such
positioning systems offer great opportunities for all devices that need to control a large number of degrees of freedom in
a restricted volume. The main advantage of fluidic actuators is their high force and power density at microscale. The
outside diameter of the actuator developed in this research is 1.3 mm and the length is 15 mm. The stroke is 12 mm, and
the actuation force is more than 0.4 N at a supply pressure of 550 kPa. The position sensor consists of two coils wound
around the cylinder of the actuator. The measurement principle is based on the change in coupling factor between the
coils as the piston moves in the actuator. The sensor is extremely small since one layer of 25 μm copper wire is sufficient
to achieve an accuracy of 10 μm over the total stroke. Measurements showed that the actuator achieves a positioning
accuracy of 20 μm in closed loop control.
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