Gas Cluster Ion Beam Pulse Switching for Precision Trimming
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional gas cluster ion beam apparatuses face limitations in achieving high-speed, high-accuracy trimming processing due to the difficulty in generating pulsed beams with short rise and fall times under high voltages, leading to reduced throughput and inability to accurately adjust film thickness distributions.
Innovation Solution
A gas cluster ion beam apparatus with a switching circuit that includes a high voltage FET and optical switching mechanism allows for high-speed, high-accuracy pulse beam generation by controlling pulse width and cycle, enabling precise trimming by varying beam residence time and mechanical scanning speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional high voltage extraction is used to generate gas cluster ion beam, then beam energy is sufficient for effective trimming, but beam pulsing capability is limited due to slow rise and fall times
Solution Approach 1:
The high voltage power supply is segmented into multiple independent voltage sources (first high voltage power supply for extraction electrode, second for acceleration electrode, third for lens electrodes). This segmentation allows the extraction electrode voltage to be pulsed independently with fast rise and fall times while maintaining sufficient beam energy through the acceleration electrode, resolving the contradiction between pulsing speed and trimming precision.
2Productivity
If DC beam with constant current is used, then stable beam energy is achieved, but processing throughput is reduced due to inability to perform high-speed trimming
Solution Approach 1:
The extraction electrode voltage is applied periodically in pulse form rather than continuously. This periodic action enables high-speed trimming by controlling pulse width and cycle, significantly improving processing throughput while the acceleration electrode maintains stable beam energy, thus achieving both productivity improvement and beam stability.
3Speed
If mechanical movement speed is increased to achieve smaller trimming amounts, then throughput is improved, but mechanical movement speed approaches its limit
Solution Approach 1:
The patent replaces mechanical speed variation with electrical pulse control. Instead of relying on mechanical movement speed to control trimming amount, the system uses pulse width modulation of the extraction electrode voltage to precisely control beam residence time and trimming amount, enabling accurate control even at high mechanical speeds and eliminating the limitation of mechanical speed limits.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables unprecedented high-accuracy trimming processing with improved throughput by allowing precise control over pulse beam characteristics, even under high voltages, overcoming limitations of conventional systems.
Implementation Method 1
a neutral cluster beam extracted from a cluster generation chamber generating the neutral cluster particles is introduced into an ionizer and by which electrons are accelerated and impacted with the neutral cluster beam to ionize the neutral cluster beam
Implementation Method 2
high voltage (several kV to several 10 kV) is applied to the ionizer, the gas cluster ions are extracted as an ion beam from the ionizer by using an extraction electrode or the like
Implementation Method 3
transports the beam to an irradiation chamber by using one or more electrostatic lenses or the like
Implementation Method 4
Gas clusters are dissociated upon collision with the surface when the gas cluster ion beam mentioned above strikes the material substrate. Average kinetic energy of each dissociated atom/molecule is approximately equal to the energy of the original gas cluster ions divided by the number of clusters
Data Source
AI summary
In order to provide a gas cluster ion beam apparatus that can perform unprecedented high accuracy trimming processing by generating a high speed and high accuracy pulse beam and adjusting a pulse width and a pulse cycle etc. thereof, a switching circuit including a switching device 32 arranged in a power supply line supplying a voltage to an ionizer 5 and an anode rod 17 with equal potential to the ionizer from an ionizing power supply 30 for accelerating ionizing thermal electrons of the ionizer 5 is provided. A gas cluster ion beam can be intermittently irradiated onto the irradiated substrate 15 by which the switching circuit SWC controls turning on and off of the switching device 32.