Manufacturing issues in copper chemical vapor deposition processes

The use of copper chemical vapor deposition and plasma etch to form interconnects for VLSI circuits have been investigated. Deposition results to date show reliable deposition of copper with bulk-like resistivity and good deposition uniformity. The effect of substrate temperature on deposition was investigated. The issues of precursor consistency and effects of contamination in the delivery system were also addressed. Feasibility of plasma etch has been investigated. Preliminary results show that the use of hard masks and wafer temperature above 160 degree(s)C are necessary. The etch chemistry used is chlorine based, adapted from an aluminum etch process. Results show anisotropic etch with some notching which is currently being addressed in further development efforts.