Inducing channel strain via encapsulated silicide formation

摘要

Methods of forming semiconductor structures having channel regions strained by encapsulated silicide formation. Embodiments include forming a transistor, depositing an interlevel dielectric (ILD) layer above the transistor, forming contact recesses exposing portions of source/drain regions of the transistor, forming metal-rich silicide layers on the exposed portions of the source/drain regions, forming metal contacts in the contact recesses above the metal-rich silicide layers, and converting the metal-rich silicide layer to a silicon-rich silicide layer. In other embodiments, the metal-rich silicide layers are formed on the source/drain regions prior to ILD layer deposition. Embodiments further include forming a transistor, depositing an ILD layer above the transistor, forming contact recesses exposing portions of source/drain regions of the transistor, forming metal liners in the contact recesses, forming metal fills in the contact recesses, and forming silicide layers on the source/drain regions by reacting portions of the metal liners with portions of the source/drain regions.

主权项

1. A method of forming a semiconductor structure, the method comprising:
forming a transistor structure including a gate on a semiconductor substrate, a channel region in the semiconductor substrate below the gate, and a source/drain region in the semiconductor substrate adjacent to the channel region; depositing an interlevel dielectric layer above the transistor structure; etching the interlevel dielectric layer to form a contact recess, wherein the contact recess exposes a portion of the source/drain region; forming a metal-rich silicide layer on the exposed portion of the source/drain region; forming a metal contact in the contact recess region, wherein the metal-rich silicide layer is encapsulated by the formed metal contact; and converting the metal-rich silicide layer to a silicon-rich silicide layer, wherein the silicon-rich silicide layer applies tensile or compressive stress to the channel region, wherein the silicon-rich silicide layer remains encapsulated by the metal contact after converting the metal-rich silicide layer to a silicon-rich silicide layer.