Highly strained channel with low-resistivity carbon-doped source/drain formed by cascade C7Hx implantation followed by rapid solid-phase epitaxy and laser annealing for n-channel metal–oxide–semiconductor field-effect transistor

Abstract

We show the systematical investigation results of the effects of the implanted ion dose of P or As under various solid-phase epitaxy (SPE) conditions on the local stress in channel regions in metal–oxide–semiconductor field-effect transistor (MOSFET) structures, and on sheet resistance and strain in carbon-doped source/drain (Si:C-S/D) layers. P or As substitution is in conflict with C substitution in Si:C layers during SPE. Furthermore, the amount of P incorporated instead of C into the Si lattice site is larger than that of As incorporated instead of C. Therefore, low-resistivity Si:C layers with low stress in the case of using P and high-resistivity Si:C layers with high stress in the case of using As are formed by single-step C7Hx implantation with rapid thermal annealing and nonmelt laser annealing, respectively. As a countermeasure, we demonstrate that cascade C7Hx implantation to control the C profiles in Si:C layers is effective for achieving high-strain channels and low-resistivity Si:C-S/D layers. Control of C profiles is a key technology for state-of-the-art complementary MOS devices with Si:C-S/D.