Effects of Al grain size on metal-induced layer exchange growth of amorphous Ge thin film on glass substrate

Metal-induced layer exchange (MILE) has attracted increasing attention as a way to lower the crystallization temperature of amorphous semiconductor thin films on insulating substrates. This paper demonstrates that the quality of the catalytic Al layer strongly influences the growth properties in the MILE of amorphous Ge. The growth velocity of the MILE significantly decreases with increasing the deposition temperature of Al (TAl: RT-200 °C), while the grain size of crystallized Ge becomes maximum (28 μm) at TAl = 100 °C. This behavior is attributed to the Al grain size depending on TAl, which influences both the nucleation frequency and the lateral growth velocity of Ge in Al. These findings give new insight into MILE for fabricating high-quality semiconductor thin films at low temperatures on inexpensive substrates.