Deflection Amplifier Settling Time Inspection via Beam Current

The patent applies preliminary action by pre-measuring the settling characteristics of the deflection amplifier during the inspection phase. The settling time is determined in advance through automated beam current measurements and integral current calculations, rather than determining it through time-consuming iterative writing and measurement cycles. This allows the optimal settling time to be established beforehand, ensuring pattern precision while enabling faster throughput in subsequent production operations.

The patent implements feedback by continuously monitoring the beam current and calculating the integral current during the settling period. The measured integral current is compared against reference values to automatically determine whether the settling time is sufficient for achieving the required pattern precision. This feedback mechanism enables dynamic optimization of the settling time, allowing the system to use the shortest possible settling time that still ensures adequate pattern dimension precision, thereby maximizing throughput.

The patent replaces the conventional mechanical inspection process (writing patterns on substrates, developing, etching, and physical measurement) with an automated electrical measurement system. By substituting the mechanical/chemical inspection chain with direct beam current measurements and integral current calculations, the system achieves settling time optimization without the time-consuming manual operations, reducing inspection time from approximately ten hours to a fraction of that time.

The patent extracts the essential measurement function from the complete pattern writing and evaluation process. Instead of performing full pattern writing, development, and measurement cycles, the invention extracts only the critical beam current measurement and integral current calculation steps that directly indicate settling performance. This extraction maintains adequate evaluation accuracy while dramatically reducing the time required, minimizing downtime for inspection and amplifier replacement decisions.