Characterization of Inter-Poly High- κ Dielectrics for Next Generation Stacked-Gate Flash Memories

In this paper, the inter-poly dielectric (IPD) thickness, scaling, and reliability characteristics of Al
2
O
3
and HfO
2
IPDs are studied, which are then compared with TEOS IPD. Regardless of deposition tools, drastically leakage current reduction and reliability improvements have been demonstrated by replacing TEOS IPD with high-permittivity (high-κ) IPDs, which are suitable for mass production applications in the future. Moreover, MOCVD deposition can be used to further promote dielectric reliability when compared to reactive-sputtering deposition. By using MOCVD deposition, the Q
BD
can be significantly improved, in addition to reduced leakage current density, enhanced breakdown voltage and effective breakdown field. Our results clearly demonstrate that both MOCVD-Al
2
O
3
and MOCVD-HfO
2
IPD possess great potential for next generation stacked-gate flash memories.