Process improvement of 0.13 μm Cu/Low K (Black DiamondTM) dual damascene interconnection

Once fab develops a reliable integration scheme, the next step of process improvement and yield enhancement is very important for semiconductor industry, especially for the 0.13 μm Cu/Low K (Black DiamondTM) dual damascene interconnection. In this paper, we discuss the process integration issues of the 0.13 μm Cu/Low K (Black DiamondTM) dual damascene integration. Solutions to the issues were explored and reported. Resist poisoning issue was solved by modifying photoresist and planarizing bottom-anti-reflective-coating (BARC) scheme. As a result there is an increase of 20% electrical yield. The impact of via etch time on interface of via bottom was studied and etch time was optimized for the best electrical performance of via chains. One of major targets of the 0.13 μm Cu/Low K (Black DiamondTM) dual damascene integration is the reliability improvement. It was observed that Cu cap etch results in different via chain profiles. Good profile of via chain is achieved after optimizing of Cu cap etch and via etch. The failure open rate of via chain and the highest dielectric breakdown field were also reported. The impacts of dual damascene cleaning on the reliability of the 0.13 μm Cu/Low K (Black DiamondTM) dual damascene interconnection was studied with splits between batch process and single wafer cleaning. On the whole, we successfully integrated 0.13 μm Cu/Low K (Black DiamondTM) dual damascene interconnection with good electrical and reliability performance after process improvement of patterning, via/Cu cap etch and dual damascene cleaning.