Low temperature rapid thermal low pressure chemical vapor deposition of [111] oriented TiN layers from the TiCl4-NH3-H2 gaseous phase

Titanium nitride layers are deposited by Rapid Thermal Low-Pressure Chemical Vapor Deposition (RTLPCVD) from the TiCl4-NH3-H-2 gaseous phase. Growth rate, resistivity and crystallographic orientation are studied as a function of the deposition temperature and the NH3/TiCl4 partial pressures ratio called R. To fulfill the TiN barrier layer requirements, the deposition temperature and the R value have to be as low as possible. We show that with such conditions, the preferential orientation of the deposited TiN layer is always [200]. This orientation enhances the [200] orientation of the aluminium overlayer which leads to poor electromigration resistance. In order to obtain [111] oriented TiN layer, a two step process is proposed. In this way, [111] oriented TIN layers are deposited at a deposition temperature and with an R ratio value as low as 500 degrees C and 4, respectively. The resistivity of such as-deposited films is 200 mu Omega cm.