Solve The Advanced Technology Of 90nm And In The Following Etching Copper Diffusion

In the development of semiconductor, the copper line to instead of the aluminum line is obviously a landmark of the improvement. Using low K material, example FSG&BD, the delay that caused bv the metal line have been reduced to a acceptant level. Damascene process solved the problem of the copper etching, and the scale of semiconductor device become smaller and smaller.This paper is one research for 90nm&blow process Cu diffuse defect in Damascene copper technology, do detail mechanism analysis and solution found.The defect can be gating by in-line KLA tool scan, all test run collect SEM cut image to do comparison then apply STR/MSTR to burn in to double confirm the result.In the Damascene process, the planar Cu surface is very important for Cu barrier seed deposition. Via ETCH must keep enough high selectivity to keep Via bottom not punch through, Post liner etch treatment is another key point, N2/H2 base can help to reduce polymer and protect Cu surface be damaged.At the same time, there are so many hill lock caused by Stress post CMP and Liner Deposition, hill lock is a challenge for Etch every step. We discussed 3 ETCH process items, following the allalysis and the validate then implement to mass production.