Effective electron mobility has been studied in MOSFETs with ultrathin silicon nitride/oxynitride stacked gate dielectrics formed by rapid thermal chemical vapor deposition. The mobility in these devices is degraded compared to those with SiO2 (the universal mobility curve). Quantitative analysis suggests that the degradation is due to coulombic scattering from both bulk charges in the dielectric and interface trapped charges. Finally, after investigating the impact of process parameters on mobility, it is concluded that interfacial oxynitride grown at higher pressure in nitric oxide is advantageous for achieving thinner effective stack thicknesses and for preserving electron mobility.
Bibliographical noteFunding Information:
This work was supported by the Semiconductor Research Corporation under contract 98-BC-616.016, the University of California Semiconductor Manufacturing Alliance for Research and Training (UC-SMART) under contract SM-98-10, and the National Defense Science and Engineering Graduate (NDSEG) fellowship.
- Charge scattering
- Electron mobility
- Silicon nitride
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Materials Chemistry
- Electrical and Electronic Engineering