The first commercially available system for non-contact measurement of the electric characteristics of 4 and 6 inch wafers.

This is a newTerahertz time domain spectrometer,which introduces the measurement of ellipsometry in combination with Terahertz spectroscopy.
The use of reflective optics makes it ideally suited for measurement of opaque materials.

Standard instrument equipped with mapping stage for non-contact, non-destructive test measurement of 4 and 6 inch semiconductor wafers.

Measurement result for GaAs epitaxial layer

Parameter n type (dope quantity:4×1018 cm-3) p type (doping quantity:1×1018 cm-3)
Carrier densityN (cm-3) 4.48×1018 1.15×1018
Relaxation time (secs) 8.47×10-14 2.51×10-14
Mobility μ (cm2/Vs) 1885 130
Resistivity p (Ω・cm) 0.74×10-3 0.042

The obtained carrier density agrees with results at Hall measurement within an error of ±10%.

Cooperation development: result measured at Hangyo laboratory in the Osaka university

The spectroscopy using terahertz waves

Terahertz spectroscopy is measured in the terahertz spectral region (THz) which is made up of frequencies located at the boundary region in the electromagnetic spectrum between light and radio waves.
Electric field strength and phase information can be measured simultaneously,by the measurement of time-domain waveforms of the electromagnetic pulse’ selectric field strength.
By analyzing the difference in the time-domain wave form of the reference and sample,it is possible to obtain the frequency dependence of the complex dielectric constant and complex refractive index , of the sample.

Product specifications

Measurement system THz Time-Domain Ellipsometry
Measurement signal Time waveform of the electric field strength
Output data Ellipsometric parameter, complex refractive index/complex dielectric constant/electric conductivity using analysis program
Sample arrangement Horizontal configuration (measurement surface : upwards looking)
Measurement zone (output range using standard reference material) above 1 ~ 3 THz
femto- second pulsed laser

Center wavelength near 780 -810 nm and pulse width less than 120 fs
(※ an external laser source can be used)

PC requirements

PC compatible with Windows OS (version 10 or later)
The PC (above) requires 1 wired LAN port and 2 USB ports for connection to the Tera Evaluator.

Software Measurement Software and Analysis Software
Dimensions/Weight 732 (W) x 585 (D) x 540 (H) mm, approximately 125 kg (※ excluding wiring and protrusions etc.)
Power source AC100 V (50/60 Hz) 10 A (an additional power outlet is recommended for the laser power supply)

※ For other requirements, please request us.