Focused ion beam characteristics, measured by using PMMA resist exposures, show significant improvement of the previously reported results for hydrogen ion beams. A beam current density of >50 mA cm−2 at 6–7 keV has been obtained over a spot size of 2.3 μm, estimated from the full width at half maximum of the intensity distribution. A single Einzel lens with magnification of about 0.1 was used. A target current density of >1 A/cm2 can be achieved with this beam for a lens system with overall magnification of ∼0.01. In experiments with Ar, both the discharge current and extracted beam current increased by more than a factor of 2 when the discharge cell length was increased by about 25% with respect to the nominal cell length for operation with H. Ar ion beams were extracted with an angular beam intensity of >5 mA sr−1, brightness (90% beam) of ∼103 A sr−1 cm−2 at 10 keV, and energy spread of ∼4.5 eV. Greatly improved beam characteristics, with brightness >104 A sr−1 cm−2, are expected by optimization of the source for Ar beams.
A surface plasma source with Penning-type electrodes is developed to generate H− beams for ion projection lithography applications. The source presently runs in pulsed mode with a pulse width of about 1 ms and repetition rate of 10 Hz. The discharge and the extracted H− beam are maintained in stable, noiseless condition; gas pressure plays a critical role here. The maximum H− beam current density at the emission surface is about 1.7 A/cm2. Preliminary measurements suggest that the normalized brightness of the core beam is ∼1.7×1013 A/(m rad)2 and its perpendicular temperature is about 0.2 eV.
A surface plasma source with Penning-type electrodes is developed to generate H− beams for ion projection lithography applications. The source presently runs in pulsed mode with a pulse width of about 1 ms and repetition rate of 10 Hz. The discharge and the extracted H− beam are maintained in stable, noiseless condition; gas pressure plays a critical role here. The maximum H− beam current density at the emission surface is about 1.7 A/cm2. Preliminary measurements suggest that the normalized brightness of the core beam is ∼1.7×1013 A/(m rad)2 and its perpendicular temperature is about 0.2 eV.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.