.300 Mm, Dry Etching Of Aluminum Corrosion Defects Optimization Study

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. Aluminum line has been applied from the earliest semi-conductor. The application of Copper line is less than 8 years. With the increase of Copper line application, the application of Aluminum has been decreasing. But Aluminum interconnect has existed for a long time, to match the method of Bonding technology. The Aluminum ETCH is absolutely necessary. One of the most important defects is Aluminum corrosion.The topic researches into the problem that the Aluminum corrosion in 90nm and less than 90nm Aluminum ETCH. Improvement of Dry ETCH process as the main means, and the improvement of the whole Aluminum ETCH flow as accessorial means. We want to get effective solution of Aluminum corrosion defect.In AL Dry Etch process Recipe, study add CH4 gas to improvement Sidewall passivation to avoid Cl react with Sidewall Al induce Corrosion, The flow of CH4 is related with transmission ratio, PR thickness, Al film thickness. So in 90nm NROM/90nm Logic/45nm Logic products'develop recipes apply different flow CH4 and combine reasonable Bias RF Power final can get best solution.In PR remove process Recipe, for Cl's volatilization, apply 300℃chamber temperature and adopt 400SCCM pure vapor to accelerate Cl volatilization in both 90nm Logic and 45nm Logic product. In 90nm NROM product, for this is single product have high Transmission Rate:about 98%, PR as Sidewall polymer source is poor,so normal PR strip recipe combine optimized post Al Etch flow is enough.Experiment show, WET Clean after Dry Etch if apply DRYER clean mode can most reduce liquid remain in the wafer surface. And after WET apply 250℃high temperature Bake (60s or 120s) can boost Cl volatilization and decrease AL metal corrosion. This is be validated at above all 3 product. So final we apply this new process flow at all 3 product.