US 7,803,702 B2 · Method for fabricating MOS transistors

Abstract

A method for fabricating metal-oxide transistors is disclosed. First, a semiconductor substrate having a gate structure is provided, in which the gate structure includes a gate dielectric layer and a gate. A source/drain region is formed in the semiconductor substrate, and a cleaning step is performed to fully remove native oxides from the surface of the semiconductor substrate. An oxidation process is conducted to form an oxide layer on the semiconductor substrate and the oxide layer is then treated with fluorine-containing plasma to form a fluorine-containing layer on the surface of the semiconductor substrate. A metal layer is deposited on the semiconductor substrate thereafter and a thermal treatment is performed to transform the metal layer into a silicide layer.

Claims14

Dependent claims

A method for fabricating a MOS transistor, comprising:

providing a semiconductor substrate;
forming a gate structure on the semiconductor substrate, wherein the gate structure comprises a gate dielectric layer and a gate conductive layer;
forming a source/drain region in the semiconductor substrate;
performing a cleaning process to remove oxides from the surface of the semiconductor substrate;
utilizing an oxidant comprising ammonium peroxide mixture (APM) or hydrogen peroxide (H2O2) to oxidize the surface of the semiconductor substrate for forming an oxide layer comprising silicon dioxide directly on the source/drain region;
after forming the oxide layer, reacting the oxide layer with a fluorine-containing plasma for forming a fluorine-containing layer;
depositing a metal layer on the semiconductor substrate;
and
performing a thermal treatment for forming a silicide layer.

6 more elements

Dependencies are inferred from the claim text.

Method for fabricating MOS transistors

Life of this patent

Method for fabricating MOS transistors

Life of this patent

Abstract

Claims14