Uniformity of Gate Dielectric for I/O and Core HK/MG pMOSFETs with Nitridation Treatments

Abstract

Uniformity consideration in integrated-circuit manufacturing is an impressive task, especially in the field of nano-node semiconductors. The use of high-dielectric-constant (high-K) materials to promote drive current in deep nano-node devices is also increasing. One solution involves enhancing the quality of the high-K dielectric layer as a gate dielectric with nitridation treatment. This study combines the aforementioned concerns in deep nano-node manufacturing and demonstrates their relationship. Given the electrical measurement of the wafers treated with decoupled plasma nitridation (DPN), a few desired key parameters, including drive current (IDS), threshold voltage (Vth), gate oxide capacitance per area (Cox), subthreshold swing (SS), and interface state density, in the design of p-channel metal–oxide–semiconductor field-effect transistors (pMOSFETs) are observed. A uniformity comparison with different DPN processes is also performed, and the uniformity of the gate dielectric in input/output and core zones is discussed. Based on the uniformity distribution, lower SS values are obtained by adopting the low-temperature nitridation treatment after high-K dielectric deposition. The increased nitrogen concentration decreases the deviation, thereby indicating improved uniformity of SS values.