Deep-Level Measurement System for Nitride Semiconductors
MDLOS-350-1600
Deep-Level Measurement System for Nitride Semiconductors MDLOS-350-1600
 
Deep-level optical spectroscopy (DLOS) is a spectroscopic technique for evaluating deep-level defects in semiconductors by optical excitation. By irradiating the sample with monochromatic light while continuously varying the photon energy and measuring changes in the depletion-layer capacitance, the energy levels and densities of deep-level defects within the band gap can be evaluated.
In DLOS measurements, when electrons (or holes) trapped at deep-level defects in the depletion layer absorb the photon energy of the incident monochromatic light and are excited to the conduction band (or valence band), the space-charge distribution in the depletion layer changes. As a result, the depletion-layer width changes, which is detected as a change in junction capacitance. By analyzing the photon-energy dependence of this capacitance change, the optical ionization energies and densities of deep-level defects can be evaluated with high sensitivity.
This system consists of a manual probe station for optical characterization and a monochromatic light irradiation unit, and can perform DLOS measurements on semiconductor devices fabricated at the wafer level. By measuring capacitance with high precision while irradiating the sample with monochromatic light, deep-level defects in semiconductors can be analyzed non-destructively.
The system is well suited to evaluating crystal defects, impurity levels, and process-induced defects in a variety of semiconductor materials and devices, such as Si, SiC, and GaN, and is an effective analytical system for semiconductor materials research and development, device development, and quality and reliability evaluation.

■Features
• Enables evaluation of deep-level defects by deep-level optical spectroscopy (DLOS).
• Measures capacitance with high precision while sweeping the photon energy of monochromatic light.
• Evaluates the optical ionization energies and densities of deep-level defects.
• Supports non-destructive measurement of semiconductor devices fabricated at the wafer level.
• Suitable for defect analysis of various semiconductor materials and devices, such as Si, SiC, and GaN.

■Specifications
Monochromatic Light
Irradiation Unit		 Wavelength range 350–1600 nm
Bandwidth (FWHM) 5 nm
Light source Xenon lamp, 500 W
Sample Stage Sample size Up to 50.8 mm diameter
Measurement surface plate material Synthetic quartz
Sample stage travel X-axis: 60 mm (coarse/fine)
Y-axis: 60 mm (coarse/fine), 110 mm (slide)
Travel per handle rotation X-axis: 20 mm (coarse), approx. 2.6 mm (fine)
Y-axis: 20 mm (coarse), approx. 2.6 mm (fine)
Manipulators Probe needles Tungsten needles
Travel 10 mm per axis (X, Y, Z)
Travel per rotation 500 μm per axis (X, Y, Z)
Carrier Equipped with a magnetic mounting plate
Number of probe manipulators 2
Ring plate material Magnetic stainless steel (SUS)
Microscope Observation magnification 7×–115×
Zoom ratio 16.4
Field of view 31.4–1.9 mm diameter
Objective working distance (W.D.) 60 mm
Objective numerical aperture (N.A.) 0.15
Eyepieces 10×, field number 22
Optical system Galilean parallel optical system
Focusing mechanism Rack-and-pinion mechanism with roller guides
Illumination Coaxial epi-illumination with LED
Observation Camera Pixel count 1.5 megapixels
Image sensor 1/2-type color CCD image sensor
Interface USB
Output resolution 1360 (H) × 1024 (V)
Effective imaging area (mm) 6.47 (H) × 4.83 (V)
Pixel size (μm) 4.65 (H) × 4.65 (V)
Color filter array RGB
Lens mount C-mount
Frame rate 12 fps
Capacitance Meter Measurement resolution 2 fF or less (2 pF range)
Maximum measurable value 2000 pF or more
Electronic Shutter Opening/closing time 20 ms or less
*Opening/closing time refers to the rise time and fall time, not the exposure pulse duration.
Exposure pulse duration 50 ms or less
Measurement Computer OS Windows 7

*Specifications and appearance are subject to change without notice for product improvement.