Growth and annealing behaviour of α-Sn on InSb(001) measured by LEED and He atom scattering

The growth and annealing behaviour of films of α-Sn deposited on In-rich InSb(001) have been studied. Monolayer films deposited at ∼ 40°C were found to exhibit disorder as evidenced by the random scattering of He atoms. LEED showed a reconstruction to a (1 × 1) surface phase. Annealing the films slowly between ∼ 100 and 220°C increased the (00) peak and produced a well defined He diffraction pattern and also changed the LEED picture. Subsequent Sn layers (up to a total of 7 layers) behaved in a similar manner with the α-Sn remaining stable to the high temperatures. During Sn deposition the shape of the (00) signal as a function of coverage was measured and was different for the first and subsequent layers. Recovery effects were measured as a function of Sn coverage and temperature. Deposition of Sn on Sn at 159°C produced the same result as low-temperature deposition and annealing to 220°C. Finally, deposition of Sn on InSb at higher temperatures was measured. It is concluded that, for at least thin films, the α-Sn films should possess less defects at the interface that should lead to better electrical properties. Further, the stability of the α-Sn to higher temperatures opens up the possibility of the deposition of other semiconductor layers on α-Sn to produce a sandwich device using a low-band-gap material.