Method for making an integrated circuit

A method for making an integrated circuit on a substrate, comprising:

• making a gate stack on a surface of an active zone, the making comprising:
• depositing a first layer of dielectric which extends over the active zone;
• depositing a gate conductive layer which extends over the layer of first dielectric;
• depositing a layer of a first metal which extends over the gate conductive layer;
• depositing a layer of a second metal which extends over the layer of the first metal;
• depositing a layer of a second dielectric which extends over the layer of the second metal;
• partially etching the gate stack for the formation of a gate zone on the active zone;
• making insulating spacers on either side of the gate zone on the active zone;
• making source and drain zones;
• making silicidation zones on a surface of the source and drain zones;
• etching, in the gate zone on the active zone, the second dielectric layer and the layer of second metal with stopping on the layer of the first metal, so as to form a cavity between the insulating spacers;
• and
• making a protective plug at a surface of the layer of first metal of the gate zone on the active zone, wherein the protective plug fills the cavity.