Improvement of Energy Recovery Efficiency for High-Voltage Power Supplies in Ion Implantation

In the doping process of semiconductor manufacturing, ion implantation technology has become one of the core links in advanced chip manufacturing due to its advantages of high doping precision and strong controllability. As the energy core of ion implanters, high-voltage power supplies not only need to provide stable high-voltage output to accelerate ion beams, but their energy recovery efficiency is also directly related to equipment energy consumption and manufacturing costs. According to industry data, about 30%-50% of the energy during ion implantation is converted into heat energy or reactive power loss due to load characteristics. Therefore, improving energy recovery efficiency has become a key direction for the technological iteration of high-voltage power supplies.
The energy recovery of high-voltage power supplies for ion implantation faces two core challenges: one is the dynamic volatility of the load. The pulsation of ion beam current and real-time adjustment of implantation dose lead to an intermittent high-volatility characteristic of the power supply load. Traditional recovery circuits with fixed topologies are difficult to match load changes, which easily cause energy reverse flow loss. The other is loss superposition under high-voltage operating conditions. In the scenario of kilovolt-level or even megavolt-level output, the conduction loss of switching devices, transformer leakage inductance, and spike voltage caused by line parasitic parameters will further reduce the effective rate of energy recovery. Although traditional RC snubber circuits can suppress spikes, they will additionally consume 10%-15% of the recovered energy.
In response to the above challenges, current technological breakthroughs focus on three dimensions: First, adaptive optimization of topology structure. By adopting an interleaved parallel Buck-Boost topology, the traditional single-channel recovery circuit is split into a multi-channel parallel structure. Combined with the design of coupled inductors, the current ripple can be reduced by more than 40%. At the same time, dynamic matching between load and topology is realized, which quickly switches the energy flow direction when the beam current changes abruptly, reducing reverse flow loss. Second, intelligent upgrading of control strategies. The model predictive control (MPC) algorithm is introduced to collect real-time data of beam intensity, output voltage, and recovery current, construct a loss prediction model, and dynamically adjust the switching frequency and duty cycle, so that the energy conversion efficiency can be maintained above 90% within the range of load fluctuations. Third, integration of device and loss suppression technologies. Wide-bandgap semiconductor devices (such as SiC MOSFETs and GaN HEMTs) are used to replace traditional silicon-based devices. Their on-resistance and switching loss are only 1/5 of those of silicon devices. At the same time, active clamp circuits are used instead of RC snubbers, which increases the spike energy recovery efficiency to 85% and significantly reduces reactive power loss.
The improvement of energy recovery efficiency brings significant application value to ion implantation equipment: from the perspective of energy consumption, for every 1 percentage point increase in efficiency, the annual power consumption of a single ion implanter can be reduced by about 2,000 kWh. Based on the scale of 100-level equipment in a semiconductor factory, the annual power saving can reach more than 200,000 kWh, which is in line with the carbon neutrality goal of the semiconductor industry. From the perspective of equipment reliability, the improvement of energy recovery efficiency means that the heat generation of devices is reduced by 30%-40%, which can extend the service life of switching devices and capacitors, reduce the failure rate of power supplies, indirectly ensure the stability of the ion implantation process, and reduce the chip yield loss caused by power supply failures.
In conclusion, the improvement of energy recovery efficiency for high-voltage power supplies in ion implantation needs to take load adaptation as the core, and break through the loss bottleneck under high-voltage dynamic operating conditions through the collaborative innovation of topology, control, and device technologies. As the semiconductor process advances to the 3nm and below nodes, the requirements for implantation dose precision and power supply energy consumption will be further improved. Energy recovery technology will also iterate towards the direction of zero loss under full operating conditions, becoming a key technology to support advanced chip manufacturing.