Forming Low-Resistivity Tungsten Contacts and Avoiding Fluorine Diffusion by Flash Lamp Annealing (FLA)

We demonstrate the formation of low resistivity W contacts using Flash Lamp Annealing (FLA). Moreover, fluorine diffusion into the underlying Ti layer is avoided using FLA. Furthermore, FLA is more effective compared to conventional RTA for decreasing the resistivity of the W layer. The presence of oxygen in W is one of the factors that prevent lower resistivity being obtained. We also show that FLA does not degrade the gate stack.