Application and Process Value of Load Balancing Technology for Exposure Machine High-Voltage Power Supply

In the semiconductor lithography process, the exposure machine, as a core piece of equipment, its imaging precision directly determines the chip line width and performance. The high-voltage power supply, serving as the core energy source for the exposure machine’s light source system (such as deep ultraviolet light sources and extreme ultraviolet light sources), needs to continuously output stable and accurate high-voltage electrical energy. However, the exposure machine’s load demand fluctuates dynamically during different lithography stages (e.g., wafer positioning, exposure scanning, dose calibration), and uneven load distribution is prone to occur when multiple energy conversion modules work in parallel. This leads to problems such as overload heating of a single module and increased output voltage ripple, ultimately causing process risks like lithography line width deviation and shortened light source lifespan. The research, development, and application of load balancing technology for exposure machine high-voltage power supplies, by dynamically adjusting the energy distribution among multiple modules, have become a key support to solve this pain point and ensure the stability of the lithography process.
The core architecture of this technology centers on multi-module collaboration + dynamic regulation and consists of three key links. First, it adopts a multi-module parallel topology, decomposing the high-voltage power supply into several independent power modules. Each module has complete energy conversion and output capabilities, and the redundant design prevents the impact of a single module failure on the overall power supply. Meanwhile, data interaction between modules is achieved through a current-sharing bus, which shares real-time core parameters such as load current and temperature, laying a data foundation for balanced control. Second, it is equipped with an adaptive dynamic current distribution algorithm. Aiming at equal distribution of total load demand, this algorithm adjusts the output current of each module through microsecond-response PWM (Pulse Width Modulation) signals, based on the real-time load rate and health status (e.g., capacitor aging degree, heat dissipation efficiency) of each module. This controls the load distribution error between modules within ±1%, avoiding long-term high-load operation of some modules. Third, it builds a real-time load monitoring and prediction mechanism. A high-frequency sampling module (with a sampling frequency of 10kHz) captures the load change curve of the exposure machine, and combines lithography process parameters (e.g., exposure dose, scanning speed) to predict the load fluctuation trend in advance. It proactively adjusts the module energy distribution before sudden load changes (e.g., increased instantaneous energy demand during wafer switching), avoiding voltage fluctuations caused by response lag.
From the perspective of process application, the value of this technology is concentrated in three core aspects. First, it improves the stability of lithography precision: The load balancing technology can control the high-voltage power supply’s output voltage ripple coefficient below 0.05%, avoiding unstable light source intensity caused by voltage fluctuations. This further reduces the lithography line width uniformity error to within 0.01μm, meeting the strict requirements for imaging precision in advanced processes of 14nm and below. Second, it extends the lifespan of the power supply system: By avoiding single-module overload, the operating temperature of each power module can be reduced by 5-8℃, and the lifespan of core components such as capacitors and IGBTs can be extended by more than 30%. This reduces the number of unplanned shutdowns and maintenance of the exposure machine, lowering the equipment operation and maintenance costs of semiconductor manufacturing. Third, it enhances process anti-interference capability: In the face of sudden load impacts of the exposure machine (e.g., instantaneous current peaks when the light source is triggered), the load balancing system can complete load redistribution between modules within 20 microseconds, quickly absorbing impact energy and preventing output voltage drop. This ensures the accuracy of the lithography dose, which is particularly critical for the manufacturing of dose-sensitive products such as high-precision chips for medical imaging.
In the process of technology implementation, two key challenges need to be overcome: One is the synchronization between modules. Clock deviations during the parallel operation of multiple modules easily lead to current distribution delays. The solution is to adopt high-precision clock synchronization technology (such as the IEEE 1588 PTP protocol) to control the clock error between modules within the nanosecond level. The other is high-frequency interference suppression. The internal electromagnetic environment of the exposure machine is complex, so the load balancing system needs to reduce the impact of electromagnetic interference on current sampling and signal transmission through shielding and grounding design, differential signal transmission, etc., to ensure the accurate execution of the balancing algorithm.
As the semiconductor industry moves toward more advanced processes of 3nm and below, the exposure machine imposes higher requirements on the load response speed and stability of the high-voltage power supply. In the future, load balancing technology will further integrate AI load prediction algorithms, learn historical lithography process data to predict the load characteristics of different wafer batches in advance, and realize predictive balanced control. At the same time, combined with the application of wide-bandgap semiconductor materials such as silicon carbide and gallium nitride, it will improve the temperature resistance and energy conversion efficiency of power modules, providing a more solid technical foundation for the high-efficiency and intelligent upgrade of the exposure machine’s high-voltage power supply.