Influence Mechanism and Technical Optimization Path of High-voltage Power Supply on Etching Rate Uniformity in Etching Process

I. Technical Challenges in Etching Process Uniformity
In semiconductor manufacturing and precision micro-processing, the uniformity of plasma etching processes directly determines device performance and production yield. As the core energy supply unit of etching equipment, the output characteristics of high-voltage power supplies and their system interactions critically influence the spatial distribution of etching rates. Experimental data indicates that when wafer surface etching rate non-uniformity exceeds 3%, the probability of chip functional failure increases exponentially. This non-uniformity originates from the synergistic effects of plasma density distribution, reactive particle transport processes, and surface reaction kinetics, with the power output characteristics of high-voltage power supplies serving as the core variable regulating these physicochemical processes.

II. Mechanism of Key Technical Parameters in High-voltage Power Supplies
1. Voltage Stability and Dynamic Response
Voltage fluctuations (<0.5% typical) directly affect sheath electric field uniformity. When output ripple exceeds critical thresholds, it causes localized plasma impedance mutations forming hotspot etching zones. Multistage LC filtering and digital feedback control can attenuate transient disturbances in the 100kHz frequency band to 0.1% of initial values.

2. Pulse Modulation Characteristics
In the time domain, nanosecond-level pulse rise times (<50ns) effectively suppress charge accumulation. Adjusting duty cycles (10%-90% adjustable) and repetition rates (1kHz-1MHz) enables spatial equilibrium of reactive particle flux. Experiments demonstrate bipolar pulse modes can reduce edge region etching rate differences to below 0.8%.

3. Dynamic Impedance Matching
Real-time plasma impedance variations (50-500Ω typical) require adaptive matching capabilities. Smith chart-based dynamic impedance matching algorithms combined with V/I dual-loop control enhance power transmission efficiency beyond 92%, significantly improving large-area substrate uniformity.

III. Technical Optimization Paths and Development Trends
1. Power Topology Innovation
Resonant soft-switching topologies achieve precise voltage regulation (0.1V steps) while reducing switching losses (<5W). Multiphase interleaved parallel technology controls output current ripple below 0.3% through phase compensation mechanisms, particularly effective for 300mm+ wafer uniformity control.

2. Intelligent Control Algorithm Integration
Deep reinforcement learning algorithms enable real-time mapping between plasma states and power parameters. By online monitoring 14-dimensional process parameters (including electron temperature, ion density, sheath thickness, etc.), predictive etching rate control maintains batch-to-batch uniformity standard deviation at σ<0.5.

3. Multi-physics Field Co-optimization
Electromagnetic-fluid-chemical coupling models quantitatively analyze power parameter impacts on plasma distribution. Simulation data shows optimized ramp voltage scanning strategies reduce radial non-uniformity by 42% while enhancing etch selectivity beyond 15:1.

IV. Industrial Application Verification
Production data from a 12-inch wafer fab demonstrates that novel adaptive high-voltage power systems improve critical dimension uniformity (CDU) by 37%, reducing etching rate standard deviation from 2.1% to 0.9%. This breakthrough elevates 3nm process yield to 92.5%, fully validating the uniformity enhancement effect of power supply innovation.

Future development will focus on atomic layer etching (ALE)-level precision control. Through sub-microsecond pulse sequencing and dual-frequency coupling technologies, the industry aims to achieve single-atom scale etching uniformity. This requires high-voltage power supplies to maintain 20kV-level outputs while enhancing current control precision to microampere levels, propelling semiconductor manufacturing into the angstrom era.