Band Edge n-MOSFETs with High-k/Metal Gate Stacks Scaled to EOT=0.9nm with Excellent Carrier Mobility and High Temperature Stability

We demonstrate, for the first time, a HfLaSiON/metal gate stack that concurrently achieves the following: low threshold voltage (V_T =0.33V), low equivalent oxide thickness (EOT=0.91nm) (T_inv =1.3nm) and 83% SiO₂ mobility. Key enablers of this result are 1) La doped HfSiON for n-FET V_T tuning 2) HfO₂:SiO₂ alloy ratio with 10% SiO₂ suppressing crystallization up to 1070degC, 3) interlayer SiO₂ (IL) to reduced bias temperature instability (BTI) and 4) plasma nitridation (N*)/post nitridation anneal (PNA) sequence for EOT scaling. This work advances high-k/band edge metal gate (MG) efforts by showing scalability of HfLaSiON to EOT=0.91nm without mobility or BTI tradeoff, while matching the V_T of a SiO₂/n-PolySi control