Epitaxial films of GaAs on (100)silicon were used as substrates for the preparation of high quality epitaxial layers of (100)CdTe, using a simple ultrahigh vacuum technique. Conditions were defined for the consistent formation of the (100)CdTe on (100)GaAs or GaAs/Si. Double crystal x-ray diffraction rocking curves for the GaAs films on Si have shown full width at half maximum as low as 20 s of arc. Both the CdTe and GaAs films are structurally stable to multiple thermal shocks between 80 K and room temperatures, and to elevated temperatures in the range of 400 to 600 °C.

This paper presents a feasibility study of an automated pick-and-place process for ultrathin chips on a standard automatic assembly machine. So far, scientific research about automated assembly of ultrathin chips, with thicknesses less than 50 µm, is missing, but is necessary for cost-effective, high-quantity production of system-in-foil for applications in narrow spaces or flexible smart health systems applied in biomedical applications. Novel pick-and-place tools for ultrathin chip handling were fabricated and a process for chip detachment from thermal release foil was developed. On this basis, an adhesive bonding process for ultrathin chips with 30 µm thickness was developed and transferred to an automatic assembly machine. Multiple ultrathin chips aligned to each other were automatically placed and transferred onto glass and polyimide foil with a relative placement accuracy of ±25 µm.

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