Titanium diboride as a metallization diffusion barrier.

Titanium diboride thin films were deposited at 600C using a glow discharge and feed gases of TiC1(4), BC1(3), and H2. These films have good ad- hesion to silicon and also have as- deposited resistivities that are low enough for use as a metallization diffusion barrier. When used as a diffusion barrier between aluminum films and both n-type and p-type silicon wafers, the titanium diboride films prevent interaction between the silicon and aluminum for thirty minute anneals at 450C and at 500C. However, at 550C signs of reaction between the aluminum films and the titanium diboride begin to appear. Electronic characteristics of the titanium diboride/silicon interface suggest that the boride may be suitable for direct contact to p-type silicon.