Design scheme P TTT 2 1200

Target design model: P-TTT-2-1200

The test target P-TTT-2-1200 has been specially developed for the characterization of Terahertz imaging systems. Featuring structures and areas from 2 µm up to 8 mm of lateral size it is suited for standard diffraction-limited systems as well as near-field imaging systems with sub-wavelength resolution.

The test target is based on high-resistivity silicon and contains conductor areas with three different transmission strengths beside uncoated substrate areas with maximum transmission. The featured structures include classic resolution test structures such as orthogonal pairs of three stripe structures, a Siemens star and concentric rings. These typical structures are accompanied by further structures specially useful for near-field imaging purposes such as metamaterial structures generating local field confinement. Additionally, areas helpful as references for sheet resistance imaging and wafer scanning applications are also listed.


Substrate material

High-resistivity FZ silicon, 2-side polished

Substrate Resistivity

> 10 kOhm cm

Target overall size 2" x 2" (50 mm x 50 mm)

Substrate thickness

525 µm

Coating materials

Cr, Au

Coating thickness

Cr: 10 nm, 65 nm and 75 nm (in semi-transparent areas)

Au: 50 nm (opaque)

Orthogonal pairs of three stripe structures 

2 – 1200 µm wide lines & spaces

45° rotated for 2 - 460 µm wide line & spaces

Siemens star

6 mm outer diameter, 18 elements

Inverted Newton rings

5.6 mm outer diameter

Ring widths from 10 – 500 µm in increasing steps

Continuous Rsh Reference areas

Four areas, each 6.7 mm x 8.3 mm

Tilted metal grating areas

Six areas, each 2 mm x 6.7 mm

Tilting angles: 0°, 18°, 36°, 54°, 72°, 90°

Bow-tie array metamaterial

300 µm length, 5µm gap

Asymmetric double slit array metamaterial

3 µm and 6 µm slit width and spaces