Al Like Schottky Barrier Diode Formation using Ti W
Original Publication Date: 1978-Jun-01
Included in the Prior Art Database: 2005-Feb-21
The formation of an aluminum (Al)-like Schottky barrier diode (SBD) (Upsilon = 0.70v) on Si is difficult because of the solubility of Si in Al. If Al is deposited directly on the Si contacts and sintered at 350-400 Degrees C, shallow junctions will be shorted due to Al penetration. The Al penetration can be prevented by doping the Al with Si to satisfy the solubility. However, during sintering the Si in the Al grows epitaxially on the Si substrate, and this Si is doped with Al (P-type). The presence of the P-layer on the N-type epi causes a major increase (0.2 volts and more) in the barrier height. The conventional method of forming an Al-like SBD involves first forming PtSi in the contact and then depositing Al followed by sintering.