Self-Aligned and Non-Self-Aligned Contact Metallization in InGaAs Metal–Oxide-Semiconductor Field-Effect Transistors: A Simulation Study

2-D simulations were performed to compare the drive currents of In_0.53Ga_0.47As n-channel metal-oxide-semiconductor field-effect transistors (MOSFETs) with self-aligned contact metallization and those with non-self-aligned contact metallization in order to determine the importance of self-aligned contact metallization in InGaAs MOSFETs at advanced technology nodes. A gate length of 15 nm was simulated, and various gap sizes between the via and the gate and various contact resistivities between the contact and the source/drain (S/D) were investigated. While very small gap sizes can significantly lower the S/D resistance for non-self-aligned contact metallization by bringing the via very close to the gate, an important benefit is still provided by self-aligned contact metallization in terms of contact area, allowing self-aligned contact metallization to outperform non-self-aligned contact metallization for the same contact resistivity, down to very low contact resistivity in the order of 10^-9 Ω·cm².