Effect of interfacial oxide on Ge MOSCAP and N-MOSFET characteristics

The effect of electrical quality of interfacial oxide on Ge MOSCAP and MOSFET characteristics is investigated. Different growth conditions are studied to optimize the interfacial layer. CV and Dit measurements are done for accurate comparison of different gate dielectric stacks. Optimized ozone oxidation process is integrated with Co-induced dopant activation to fabricate Ge N-MOSFETs. Forty percent improvement in inversion electron mobility is demonstrated with optimized GeO2 passivation. The highest electron mobility is reported in bulk Ge N-MOSFETs with GeO2/Al2O3 gate dielectric stack.