PMOS with HKMG

Abstract

The invention discloses a PMOS with a HKMG. The HKMG comprises a gate dielectric layer and a metal gate. A first work function layer and a second work function layer are between the gate dielectric layer and the metal gate. The first work function layer is a work function layer of the PMOS. The second work function layer is a work function layer of the NMOS. A first barrier layer is between the first work function layer and the second work function layer. The first work function layer, the first barrier layer, and the second work function layer form a superposed structure. The first barrier layer is used to prevent the influence of the material of the second work function layer and the metal gate on the first work function layer, so that the performance of the PMOS is stable. According tothe invention, the metal material of the metal gate can be prevented from penetrating into the work function layer of the PMOS tube at the bottom, and therefore the stability of the PMOS is improved;no additional shimming is added, the process complexity is not increased, and the process cost is low; and the characteristics of the NMOS will not be affected.

Description

technical field [0001] The invention relates to a semiconductor integrated circuit, in particular to a PMOS with HKMG. Background technique [0002] HKMG has a gate dielectric layer with a high dielectric constant (HK) and a metal gate (MG), so it is usually abbreviated as HKMG in the art. Such as figure 1 As shown, it is a structural diagram of an existing PMOS with HKMG. The HKMG of an existing PMOS with HKMG includes a gate dielectric layer and a metal gate 108, [0003] The gate dielectric layer includes a high dielectric constant layer 102 . The material of the high dielectric constant layer 102 includes silicon dioxide (SiO2), silicon nitride (Si3N4), aluminum oxide (Al2O3), tantalum pentoxide (Ta2O5), yttrium oxide (Y2O3), hafnium silicate Oxygen compound (HfSiO4), hafnium dioxide (HfO2), lanthanum oxide (La2O3), zirconium dioxide (ZrO2), strontium titanate (SrTiO3), zirconium silicate oxide compound (ZrSiO4), etc. [0004] An interfacial layer (IL) is usually dis...

AI Technical Summary

Problems solved by technology

However, in actual application, after the P-WF layer passes through the process steps, its P-WF layer will be affected by the metal of the upper N-WF layer and the metal gate, such as Al. Different manufacturing environments and temperature effects, Al will migrate to the bottom, Affect the P-WF layer, causing instability and low yield of components

For example, in the subsequent process (Back End Of Line, BEOL), the thermal effect of BEOL will cause the Al in HKMG to diffuse downwards and bond with other elements to affect the P-WF layer; Through the P-WF layer and the bottom tantalum nitride layer 104 and titanium nitride layer 103, combined with the high dielectric constant layer of the gate dielectric layer, it will deteriorate the PMOS component

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