| | Exposition Control System EXPO Exposition control system EXPO is intended for the shaped E-beam litograpy on the BS600, BS601 and BS601M instruments.
HW part is based on the Xilinx Virtex 4 module with 1Gb Ethernet connection. 3 pairs of fast 16 bit D/A converters generate coarse and fine x,y output voltages for deflection amplifiers and a,b voltages for the shaping amplifiers. Flash A/D coverters provide the video input and inputs from x,y laser beam interferometers.
| Exposition HW parameters: | Xilinx Virtex 4, 1Gb Ethernet
| | Max. size of the exposition field: | 3100 x 3100 um
| | 16 bit D/A deflection converters LSB: | Basic 50 nm, fine 2,5 nm
| | Max. size of the shaped beam: | 6.3 x 6.3 um
| | Shaping D/A converters LSB: | 0,1 nm
| | Video signal input: | 8 bit FLASH A/D (block REM EXPO)
| | Laser interferometer inputs: | 2 x 2 channels 8 bit FLASH A/D |
EXPO ProgramProgram EXPO processes the exposition described in .ASB format with extension for bitmaps and periodical grids. The exposition data can be read from an external program (G-MASTER) or created using internal powerful editor. Built-in graphical simulator helps the user verify the exposed stuctures including the exposition times.
Program EXPO generates the stage movement commands, then resolves the structures from .ASB format to the single stamps defined by coordinate x,y, size a,b and exposition time and sends them into the exposition hardware.
REMEXPO mode shows desired area (e.g. for the mark scanning), other special modes were implemented for the calibration, exposition field stitching and exposition alignment. Large libraries consist number of standard elements from the single rectangular structures up to the Fresnel lens.
 Deflection amplifiers DEFLFast current ampifiers DEFL are inteded for the E-beam deflection coils supply. Control voltage inputs can be connected e.g. to the EXPO module outputs.
Dynamic features were optimized according the rate of beam movements during typical exposition.
| Current range: | +/- 3.3A
| | Control voltage inputs: | 0-10V (EXPO outputs)
| | Power elements: | MOSFET transistors (no storage time)
| | Current resolution: | 1 LSB=100uA
| | Settling time: | 600ns/10mA
| | Reference low inductive resistor: | 250W, stability 1ppm/°C
| | Cooling: | thermostatic stabilized water |
Fresnel ProgramProgram generates exposition data for the creation of the Fresnel lens using the EXPO system. Wide range of proportions and other parameters can be defined, actually implemented as a part of EXPO library.
G-MASTER ProgramG-MASTER program generates data for the exposition of periodical grid structures with user defined features.
EBL stage control system STGControl system for the stepper motor driven EBL stage, wafer handling mechanism, vacuum valves including laser beam interferometer inputs and power electronics is placed in standalone 19" rack. High level commands are sent from the host PC (e.g. EXPO program).
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