Wafers

1. SOI wafers with thin layers for VLSI
    Active layer thickness: 50 – 400 nm
    Buried oxide layer thickness (thermal oxide): 100 – 400 nm
    Technology: bonding of wafers and splitting by ion cut

2. SOI wafers with thick layers for MEMS and power devices

    Active layer thickness: 5 – 100 µm
    Buried oxide layer thickness up to 1 µm for thermal oxide and 3 µm for CVD oxide
    Technology: grinding and polishing of donor wafer

   › Thinning of silicon wafers by grinding

   › Measurement of wafer parameters:

1. Geometry parameters measurement (WARP, BOW, Thickness, flatness) by laser interferometry
    • Diameters of wafers: 100 mm, 150 mm and 200 mm
    • Accuracy: 0,1 µм
    • Dynamic range of measurements: 30 µм

2. Roughness measurements by AFM
    • Diameters of wafers: 100 mm, 150 mm and 200 mm
    • Measurement range along Z: 7 µm
    • Resolution along Z: 0,05 nm
    • Measurement range along XY: 90 µm
    • Resolution along XY: 0,5 nm

3. Thickness measurement of thin multylayer structures and optical characteristic (reflection, refraction and absorption coefficients) of semiconductor wafers by spectral ellipsometry
    • Diameters of wafers: 100 mm, 150 mm and 200 mm
    • Range of wavelength: 265 nm – 1700 nm
    • Range of thicknesses: 1Å – 100 µm
    • Ultimate thickness measurement accuracy (1σ): 0,25 Å

4. Resistivity measurement of semiconductor wafers by 4 point probe
    • Diameters of wafers: 100 mm, 150 mm and 200 mm
    • Range of measurements: from 1×10-3 up to 8×109 Om/□
    • Relative error < 0.2 %