Investigation of Border Trap Characteristics in the AlON/GeO2/Ge Gate Stacks

Aluminum oxynitride (AlON) is investigated as a germanium oxide (GeO) desorption barrier layer for Ge MOSFETs. Interface and border traps in the AlON/GeO ₂ /Ge gate-stack are discussed in detail and compared with those in the Al ₂ O ₃ /GeO ₂ /Ge gate-stack via MOS and MOSFET structures. Although the interface traps remain the same for AlON and Al ₂ O ₃ in the gate stacks, the AlON gate-stack exhibits a reduced border trap, which results in improved reliability over the Al ₂ O ₃ gate-stack. This is supported by both the charge-trapping and low-frequency noise analyses.