Improved Electrical Characteristics of ~0.5 nm EOT Ge pMOSFET With GeON Interfacial Layer Formed by NH3 Plasma and Microwave Annealing Treatments

A hole mobility of ~650 cm
²
/V-s at
${N}_{\textsf {inv}}= \sim \textsf {0.4}\times \textsf {10}^{\textsf {12}}$
cm
⁻²
, a gate leakage current density of ~10
⁻⁵
A/cm
²
at
${V}_{G}= {V}_{\textsf {FB}}+ \textsf {1}$
V, and an equivalent oxide thickness of ~0.5 nm in Ge pMOSFETs are simultaneously achieved by using the GeON interfacial layer (IL) formed with NH
₃
plasma and microwave annealing (MWA) treatments. The high performance can be attributed to the O–N polar covalent bonds in GeON, which is efficiently annealed by the MWA to increase the Ge oxidation sate in the IL. Ge out diffusion or GeO desorption can be suppressed by an MWA thanks to less thermal budget.