Next Generation Low Temperature Polycrystalline Materials For Above Ic Electronics. High Mobility N- And P-Type Iii-V Metalorganic Vapour Phase Epitaxy Thin Films On Amorphous Substrates

We report on the growth and electronic properties of polycrystalline III-V semiconductors, which to date have not been discussed in depth in the literature. III-V polycrystalline semiconductor thin films were grown by metalorganic vapour phase epitaxy in the temperature range 410 degrees C-475 degrees C, which is compatible for integration into the Back-End-Of-Line (BEOL) silicon based integrated circuits. The thickness of the films in this study is in the range of tens to a few hundreds of nanometers, and deposited on amorphous substrates (either smart-phone-grade glass or Si/SiO2) and, also, on oxidised GaAs epi-ready wafers. Extensive AFM, SEM and TEM analyses show interlinked-to-continuous polycrystalline III-V films based on In(Al)As or GaSb. Hall-van der Pauw measurements return results of high mobility and controllable charge density for n- and p-type field effect transistors. In the GaAs/In(Al)As system, electron density ranging from 1 x 10(16) to 1 x 10(19) cm(-3) (n) was achieved, with room temperature mobility values in the range of 100-150 cm(2) V-1 s(-1) and hole mobility values in the range of 1-10 cm(2) V-1 s(-1) have been measured in Zn doped samples. Polycrystalline GaSb films demonstrated p-type behaviour (1 x 10(17) cm(-3)) with remarkably high room temperature hole mobility values up to 66 cm(2) V-1 s(-1) for the films grown on Si/SiO2 substrate (and 300 cm(2) V-1 s(-1) for the GaAs substrate where an epitaxial process is actually in place). Materials could be stacked into heterostructures, providing a promising platform for complex devices enabling compatible n- and p- hetero-layers for 3D integration formed at temperatures <= 480 degrees C.