Effect of Thermal Annealing on Low-K Dielectrics for iBEOL in View of 3D Sequential Integration

This work presents an in-depth study of the thermal stability of low-k material in view of intermediate Back-End-Of-Line (iBEOL) for 3D sequential Integration. SiOCH ULK were analyzed after thermal annealing up to 600°C. Moreover, the stability and reliability of this ULK material coupled with W metal in line 1 integration is characterized up to 550°C, 5 h. We have demonstrated that low-k material can support a thermal budget of 500°C, 2h with limited outgassing. This result is fully compatible with 3D sequential integration.