Preserved p-type performance of MoTe2 transistors via TeO2 dielectric buffer

Two-dimensional (2D) semiconductors show great promise for the post-Moore era, but the high-quality dielectric deposition remains a critical challenge. This is especially true for p-type 2D field-effect transistors (FETs), where precursor-induced n-type doping on the 2D channel severely changes their pristine properties. Here, we propose a TeO2 buffer layer strategy to alleviate this doping issue. The dielectric buffer protects the 2D channel (MoTe2) from interaction with precursors during dielectric deposition, and provides nucleation sites to facilitate uniform and dense dielectric growth. The TeO2/HfO2 hybrid dielectric layers show good uniformity and a high dielectric constant of 18.6. With the TeO2 buffer, the devices achieve a p-type on/off ratio of ∼106 and a small threshold voltage shift. In addition, this strategy is applicable to various contact metals and enables the fabrication of top-gate p-type FETs. This approach offers a viable pathway for integrating p-type 2D FETs and advances the realization of 2D material-based CMOS technology.