Contact Angles Between III–V Melts and Several Substrates

The wetting behavior of several melts with different III–V compound semiconductors is studied. The characteristic parameter measured is the contact angle of a melt drop with a solid. It is evaluated by a geometrical measurement of the melt drop. The importance of clean surfaces of drop and solid is shown. Contact angles between 20° and 60° are found, depending on the type and composition of the melt and substrate. The temperature dependence amounts to about −4° per 100 K increase. In addition, the contact angle varies with the substrate orientation. The (100) orientated substrates are wetted better than (111) A orientated ones.