Ion beam lithography instrument requirements and options to consider.
Instrument component
Important features, requirements, and options
Ion source and ion optics
Highly bright, small spot ion source Long-term source emission stability and a reasonable lifetime Optics design and lens operation optimized for best focus and optimal beam profile, high on-axis angular intensity at various currents, easily changeable for the smallest features as well as for m, mm, and perhaps cm sized patterns Accurate beam placement and low distortion beam deflection
Sample stage
Accurate stage translation with nm steps and high repeatability Rotation and tilt for 3D applications and process development Sample size from mm² for process development to wafer-scale, supporting mix and match with other lithography techniques Exact absolute position addressing for blind navigation High position stability by sample mounts and stage concept Position monitoring, control, and automatic corrections
Pattern generation electronics and beam control
Suitable patterning electronics speed, buffer memory size, and DAC resolution Stable, low-noise electronics (pattern generator, amplifier, supplies) Fast beam blanking and accurate timing of blanking Available various beam deflection styles and built-in patterns
Software
Offering both intuitive manual and automated, unattended operation Supporting lithography pattern design file formats, like GDSII Handling all basic patterning parameters and advanced features like groups, higher level ordering and repetition, pattern alignments, or automatic corrections (see Section 4 for patterning concepts) Allowing user defined sample coordinate-based navigation Available live feedback and end-point detection techniques
Sample chamber and additional capabilities
Architecture and overall arrangement of stage and column should support the main purpose of the instrument Accommodating samples and wafers of appropriate size Suitable loading mechanisms (possibly through load lock) Gas injectors, detectors, microprobes, and other customization should be installed based on need
