METHOD TO FORM SILICIDE AND CONTACT AT EMBEDDED EPITAXIAL FACET

摘要

An integrated circuit with an MOS transistor abutting field oxide and a gate structure on the field oxide adjacent to the MOS transistor and a gap between an epitaxial source/drain and the field oxide is formed with a silicon dioxide-based gap filler in the gap. Metal silicide is formed on the exposed epitaxial source/drain region. A CESL is formed over the integrated circuit and a PMD layer is formed over the CESL. A contact is formed through the PMD layer and CESL to make an electrical connection to the metal silicide on the epitaxial source/drain region.

主权项

1. An integrated circuit, comprising:
a substrate comprising semiconductor material extending to a top surface of the substrate; field oxide disposed in the substrate; a first metal oxide semiconductor (MOS) transistor of a first polarity, comprising:
a gate dielectric layer at the top surface of the semiconductor material;a gate over the gate dielectric layer of the first MOS transistor;a first epitaxial source/drain region in the substrate between the gate of the first MOS transistor and the field oxide, abutting the field oxide, having an angled facet facing the field oxide such that the first epitaxial source/drain region is laterally separated from the field oxide at a top surface of the field oxide by a gap which extends at least 20 nanometers down from the top surface of the field oxide;a second epitaxial source/drain region in the substrate adjacent to the gate of the first MOS transistor, opposite from the first epitaxial source/drain region; andsource/drain spacers laterally adjacent to the gate of the first MOS transistor;a gate structure over the field oxide, comprising:
a gate over the field oxide, such that the gate does not overlap an edge of the field oxide; andsource/drain spacers laterally adjacent to the gate of the gate structure; a gap filler of silicon dioxide-based dielectric material in the gap, abutting the field oxide and extending down to and contacting the first epitaxial source/drain region at a bottom of the gap; metal silicide on the angled facet of the first epitaxial source/drain region; and a contact on the metal silicide on the angled facet of the first epitaxial source/drain region.