When you state "High Speed Pattern Generator" in the Features section, is this possible to quantify? Some of your competitors, for example, state, "Pixelrates up to 40 MHz can be realized..."
A:
The pixelrate of our present Elli30 PCIe PG is 20 MHZ (for preceding Elli29 PCI is 7 MHz). This is much enough for almost all lithography applications because:
all resists have limited sensitivity and we need to wait in every point (dwell time) to accumulate desirable dose. The smaller features you want to write the smaller beam ( and low current) you should use and more time you need to wait.
all modern SEMs have limited bandwidth of deflection systems (especially for external scan), from our experience they are in range 100 kHz - 5 mHz. So, it is absolutely uselessly to have pixelrate above this value.
From our point of view the most important characteristic of lithographic system is productivity. Our competitors do not mention about this, but:
in reality they spend a lot of time (from 10% to 500% in dependence of picture complexity) for settling the beam between jumps. Besides they have to use the beam blanker to cut the beam during settling.
such system that uses digital signal processor (DSP) spend some time for loading data to DSP from PC and then they spend some time inside the DSP to transform received data to writing primitives.
From our point of view very important characteristic is Dwell Time resolution. It characterise the dose resolution between nearest elements. But our competitors even do not mention it.
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