System for pre-deposition treatment of a work-function metal layer

Abstract

A system for providing a pre-deposition treatment (e.g., of a work-function layer) to accomplish work function tuning. In various embodiments, a gate dielectric layer is formed over a substrate, and a work-function metal layer is deposited over the gate dielectric layer. In some embodiments, a first in-situ process including a pre-treatment process of the work-function metal layer is performed. By way of example, the pre-treatment process removes an oxidized layer of the work-function metal layer to form a treated work-function metal layer. In some embodiments, after performing the first in-situ process, a second in-situ process including a deposition process of another metal layer over the treated work-function metal layer is performed.

What is claimed is: 
     
         1 . A processing system, comprising:
 a plurality of processing chambers each of which adjoins a wafer handling chamber including a transfer arm configured to transfer a substrate from one to another of the plurality of processing chambers;   a vacuum system coupled to the plurality of processing chambers and the wafer handling chamber, wherein the vacuum system is configured to maintain a vacuum condition of each of the plurality of processing chambers and the wafer handling chamber;   a first chamber of the plurality of processing chambers configured to deposit a gate dielectric layer over the substrate;   a second chamber of the plurality of processing chambers configured to deposit a work-function metal layer over the gate dielectric layer;   a third chamber of the plurality of processing chambers configured to perform a pre-treatment process of the work-function metal layer and thereby form a pre-treated work-function metal layer; and   a fourth chamber of the plurality of processing chambers configured to deposit a subsequent metal layer over the treated work-function metal layer.   
     
     
         2 . The processing system of  claim 1 , wherein the pre-treatment process includes introduction of at least one of a Cl-based and a F-based metal precursor into the third chamber. 
     
     
         3 . The processing system of  claim 1 , wherein the pre-treatment process is performed at a temperature from approximately 300 degrees Celsius to approximately 1000 degrees Celsius. 
     
     
         4 . The processing system of  claim 2 , wherein a flow rate of the at least one of the Cl-based and the F-based metal precursor is between approximately 100 sccm and approximately 8000 sccm. 
     
     
         5 . The processing system of  claim 1 , wherein the work-function metal layer includes at least one of TiN, TaN, TiAlC, TiAl, TiSiN, TaSi, and TiAlN. 
     
     
         6 . The processing system of  claim 1 , wherein the subsequent metal layer includes a TiAlC layer. 
     
     
         7 . The processing system of  claim 1 , wherein the second chamber and the fourth chamber are configured for atomic layer deposition of the work-function metal layer and the subsequent metal layer, respectively. 
     
     
         8 . A processing system, comprising:
 a first evacuated chamber of a plurality of processing chambers configured to deposit a gate dielectric layer over a substrate;   a second evacuated chamber of the plurality of processing chambers configured to deposit a work-function metal layer over the gate dielectric layer;   a third evacuated chamber of the plurality of processing chambers configured to perform a pre-treatment process of the work-function metal layer and thereby form a pre-treated work-function metal layer; and   a fourth evacuated chamber of the plurality of processing chambers configured to deposit a subsequent metal layer over the treated work-function metal layer.   
     
     
         9 . The processing system of  claim 8 , further comprising:
 the plurality of processing chambers each of which adjoins a wafer handling chamber including a transfer arm configured to transfer the substrate from one to another of the plurality of processing chambers.   
     
     
         10 . The processing system of  claim 9 , further comprising:
 a vacuum system coupled to the plurality of processing chambers and the wafer handling chamber, wherein the vacuum system is configured to maintain a vacuum condition of each of the plurality of processing chambers and the wafer handling chamber.   
     
     
         11 . The processing system of  claim 9 , further comprising:
 a load lock chamber which adjoins the wafer handling chamber and provides for transfer of the substrate into and out of the processing system.   
     
     
         12 . The processing system of  claim 8 , wherein the work-function metal layer includes at least one of TiN, TaN, TiAlC, TiAl, TiSiN, TaSi, and TiAlN. 
     
     
         13 . The processing system of  claim 8 , wherein the pre-treatment process includes introduction of at least one of a Cl-based and a F-based metal precursor into the third chamber. 
     
     
         14 . The processing system of  claim 8 , wherein the subsequent metal layer includes a TiAlC layer. 
     
     
         15 . In a processing system, a method comprising:
 while maintaining a vacuum condition of the processing system:
 depositing a work-function metal layer over a gate dielectric layer in a first chamber of the processing system; 
 performing a first in-situ process including a pre-treatment process of the work-function metal layer in a second chamber of the processing system to form a treated work-function metal layer; and 
 after performing the first in-situ process, performing a second in-situ process including depositing a subsequent metal layer over the treated work-function metal layer. 
   
     
     
         16 . The method of  claim 15 , wherein the subsequent metal layer includes a TiAlC layer. 
     
     
         17 . The method of  claim 15 , further comprising after performing the second in-situ process, performing a third in-situ process including depositing a TiN layer over the subsequent metal layer. 
     
     
         18 . The method of  claim 17 , wherein the second in-situ process is performed in a third chamber of the processing system, and wherein the third in-situ process is performed in a fourth chamber of the processing system. 
     
     
         19 . The method of  claim 15 , wherein the work-function metal layer includes an N-type work function metal layer. 
     
     
         20 . The method of  claim 15 , wherein the pre-treatment process removes an oxidized layer from a top surface of the work-function metal layer.