Electrical characteristics of GaAs bonded to Si using SeS2 technique

We have developed a new technique for bonding GaAs on Si susbtrates; called surface modification by chemical treatment. The treatment of selenium sulp hide (SeS2) with GaAs produces a reconstructed surface which helps in stron g fusion between GaAs and Si at lower temperatures and without weights. The current-voltage (I-V) characteristics of both n-GaAs/n-Si and p-GaAs/p-Si were measured at room temperature. The I-V curve did not show a rectifying behaviour when GaAs was bonded to Si with SeS2 because of the formation of a high-resistance layer at the interface. The characteristics were greatly improved by small additions of Sn to SeS2 during the bonding process. Sn fo rms localized islands in addition to the Ga-Se and Se-S, and acts as shunt resistance between GaAs and Si.