کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
753063 | 895492 | 2011 | 5 صفحه PDF | دانلود رایگان |

Flat band voltage (VFB) roll-off in long channel devices at thin equivalent oxide thickness (EOT) is studied on SiO2/nitrided-HfSiO stacks. VFB increases when SiO2 interfacial layer thickness decreases, and charges pumping (CP) frequency sweep analysis shows higher trap density near Si/SiO2 interface. Based on this observation, an atomic diffusion model is introduced. Higher concentration of nitrogen atom in the HfSiO(N) layer diffuses to the Si/SiO2 interface through the SiO2 layer in thinner SiO2 device, and accumulates near Si/SiO2 interface which can introduce higher density of interfacial traps. Lifetime extracted from negative bias temperature instability (NBTI), and mobility are also degraded in thinner SiO2 devices due to the higher interfacial trap density.The VFB roll-off can be improved by lowering nitrogen concentration in the HfSiO(N) layer from optimizing plasma nitridation pressure, decreasing post deposition anneal temperature, or using defect absorbing layer on the high-k oxide.
► VFB increases when interfacial layer decreases due to the higher trap density near the interface.
► Higher concentration of nitrogen atom diffusion introduces higher interfacial trap density.
► The VFB roll-off can be improved by process development reducing nitrogen diffusion.
Journal: Solid-State Electronics - Volume 62, Issue 1, August 2011, Pages 67–71