Magnetic Testing
Wafer-Level Magneto-Optic Kerr Measuring Instrument
Magneto-optic Kerr Effect (MOKE)
Wafer-level MOKE platform for fast, non-contact magnetic characterisation of multilayer MRAM stacks, magnetic storage media and sensor films.
Product Overview
Wafer-Level Magneto-Optic Kerr Measuring Instrument
The Wafer-Level Magneto-Optic Kerr Measuring Instrument uses the poloidal magneto-optical Kerr effect (MOKE) to quickly and globally detect the magnetic properties of wafer stacks.
The system performs non-contact magnetic characterisation, which avoids damage to wafers that may occur with traditional magnetic measurement techniques. This makes it suitable for sample testing before and after wafer patterning processes.
Strong magnetic field excitation and ultra-high sensitivity Kerr detection allow researchers and engineers to analyse complex multilayer magnetic structures used in modern devices.
System Capabilities
The Wafer MOKE system can provide:
- Up to 2.5 T vertical magnetic field
- Up to 1.3 T in-plane magnetic field
These strong magnetic fields can induce switching in different layers of MRAM film stacks, including:
- Free layer
- Reference layer
- Pinned layer
The system offers ultra-high Kerr detection sensitivity, allowing simultaneous characterisation of subtle magnetic changes in multilayer films.
By combining laser point-by-point detection with scanning imaging, the instrument can quickly generate a global magnetic property map of an entire wafer, helping with:
- Process optimisation
- Yield monitoring
- Magnetic uniformity analysis
Performance Indicators and Advantages
Sample Compatibility
- Supports up to 12-inch wafer testing
- Backward compatible with smaller wafers
- Supports fragment or partial wafer testing
Magnetic Field Performance
- Maximum vertical magnetic field: ±2.5 T
- Magnetic field resolution: 1 μT
Magnetic Detection Sensitivity
- Kerr rotation detection sensitivity: better than 0.3 mdeg (RMS)
- Suitable for multilayer magnetic film stack characterisation
Positioning Accuracy
- Sample repeat positioning accuracy: better than ±1 μm
- Static positioning jitter: ≤ ±0.25 μm
Functions and Application Scenarios
MRAM Device Testing
- Vertical hysteresis loop measurement of MRAM stacks and device arrays
- Uses Polar Kerr configuration for MRAM film analysis
Magnetic Storage Media Testing
- Vertical hysteresis loop measurement for magnetic disks and storage media
- Suitable for PMR disk characterisation
Magnetic Sensor Film Testing
- Measurement of in-plane hysteresis loops in magnetic sensor film stacks
Automated Magnetic Property Mapping
The system can automatically extract hysteresis loop parameters including:
- Free layer coercivity (Hc)
- Exchange field (Hex)
- Saturation magnetisation (Ms)
It can then generate distribution maps of wafer magnetic properties.
Flexible Scanning Modes
The system provides several scanning options:
- Single-point scanning
- Array scanning
- Ring distribution scanning
- Import of custom scanning position lists
Operation Modes
- Manual wafer loading
- Fully automatic operation
This flexibility allows the system to be used in both R&D laboratories and industrial production environments.
Measurement Results
Hysteresis Loop Measurement of Perpendicular Magnetic Anisotropy Stack
Coercive Field Distribution Map of 8-inch Magnetic Wafer
Related Products
Explore adjacent systems and categories that are commonly evaluated together in hard magnetic testing workflows.