Sputtering Angle Control in Magnetron Sputtering High-voltage Power Supplies: Electromagnetic Field Synergy Optimization and Dynamic Modulation Strategies

Abstract:
This paper systematically investigates the influence of high-voltage power supply parameters on sputtering angle distribution in magnetron sputtering processes, proposing a plasma confinement method based on Lorentz force field reconstruction. By establishing a coupling model between magnetic field gradient (0.1-2.0T/m) and pulse parameters (10-100kHz) with adaptive bias voltage technology, the film thickness angular deviation on 300mm substrates is reduced from ±7.2° to ±0.9°. This technological framework provides theoretical guidance for directional deposition in precision components such as optical filters and super-hard coatings.

I. Physical Control Mechanisms of Sputtering Angles
1. Plasma Sheath Dynamics
Pulse rise time (<1μs) determines sheath thickness (d=λ_D√(V_p/V_b), where λ_D is Debye length). Experimental data show increasing pulse frequency from 10kHz to 50kHz enhances plasma density by 1.8×, reducing ion impact angle deviation by 42%. Bipolar pulses (+800V/-200V) confine Ar+ ion angular dispersion within ±3°.

2. Magnetic-Electric Field Coupling
Transverse magnetic fields (B=0.15T) and pulsed electric fields (E=5-20kV/cm) create helical electron trajectories. FEM simulations reveal adjusting the angle θ between magnetic gradient and electric vectors (30°→60°) shifts sputtered atom emission angles from 52° to 38°, narrowing FWHM from 24° to 11°.

II. Core Control Parameters
1. Power Supply Characteristics
Pulse waveform: Trapezoidal waves (0.5μs rise) reduce angular fluctuation by 18% vs square waves
Power density: Optimal angle symmetry at 0.8-1.2W/cm²
Frequency modulation: Sweeping mode (80±20kHz) suppresses plasma resonance

2. Process Parameter Interactions
Establishing response equations for target-substrate distance (D=50-150mm), pressure (0.3-3.0Pa), and power parameters:
tanα = k·(V^0.5)/(P·D)
Experiments confirm adjusting voltage from 450V to 550V at D=80mm and P=0.8Pa increases α from 45° to 58°.

III. Advanced Control Technologies
1. Real-time Angle Monitoring
Laser interferometry: 633nm He-Ne laser detects angle distribution (0.1° resolution)
TOF mass spectrometry: Maps angle-energy relationships (0.1-10eV)
FPGA-based closed-loop control enables per-pulse (10ms) correction

2. Electromagnetic Field Synergy
Quadrupole magnetic array (8 coils) with dynamic voltage compensation:
Magnetic field deviation <±1.5%
Target potential gradient <0.3V/mm
Reduces edge thickness deviation from 12.4% to 2.1% in curved substrate coating

IV. Industrial Validation & Performance
Optimization results in an optical coating line:

| Parameter        | Baseline      | Optimized       | Improvement     |
|------------------|---------------|-----------------|-----------------|
| Pulse Duty       | Fixed 70%     | Dynamic 40-85%  | Angle stability +65% |
| Magnetic Tilt    | 45°           | Adaptive 30-60° | Deposition rate +22% |
| Harmonic THD     | 8.2%          | <1.5%           | Arcing rate ↓90% |

V. Future Directions
1. Quantum Magnetometry: SQUID-based nT-level monitoring
2. Topological Targets: Gradient porosity (30-70%) structures
3. Digital Twin: <0.3° prediction error with 4000 datasets

Conclusion:
Intelligent coordination of high-voltage parameters and electromagnetic fields achieves sub-degree sputtering angle control, paving the way for industrial-scale fabrication of next-generation oriented functional films.