Method for forming a plug structure and related plug structure thereof

Abstract

A method for forming a plug structure by utilizing a punching through process and the related plug structure are provided. An opening is defined in a substrate, and an unwanted oxide residue is disposed on a bottom of the opening. A glue layer is subsequently formed over the substrate. Portions of the glue layer are disposed on the sidewall and bottom of the opening, and cover the oxide. Thereafter, the portion of the first glue layer disposed at the bottom of the opening is punched through until the substrate is exposed so as to remove the oxide. Next, the opening is filled with a conductive structure.

1 . A method for forming a plug structure, the method comprising:
 providing a substrate, the substrate comprising a dielectric layer, an opening defined in the dielectric layer forming a first glue layer over the substrate, the first glue layer being disposed on a sidewall and the bottom of the opening;   punching through a portion of the first glue layer disposed at the bottom of the opening until the substrate is exposed; and   filling the opening with a conductive structure.   
   
   
       2 . The method of  claim 1 , further comprising a step of forming a second glue layer over the substrate after the first glue layer is punched through. 
   
   
       3 . The method of  claim 2 , further comprising a step of forming a barrier layer over the substrate after the second glue layer is formed. 
   
   
       4 . The method of  claim 1 , further comprising a step of forming a barrier layer over the substrate after the first glue layer is punched through. 
   
   
       5 . The method of  claim 4 , further comprising a step of punching through a portion of the barrier layer disposed at the bottom of the opening after the barrier layer is formed. 
   
   
       6 . The method of  claim 1 , further comprising a step of forming a barrier layer over the substrate before the first glue layer is punched through. 
   
   
       7 . The method of  claim 6 , wherein the step of punching through the portion of the first glue layer also punches through a portion of the barrier layer disposed at the bottom of the opening. 
   
   
       8 . The method of  claim 1 , further comprising a step of performing a pre-cleaning process before the first glue layer is formed. 
   
   
       9 . The method of  claim 8 , wherein the pre-cleaning process comprises an argon (Ar) or F-base pre-cleaning process. 
   
   
       10 . The method of  claim 1 , wherein the step of punching through the portion of the first glue layer is performed by using an anisotropic etching process. 
   
   
       11 . The method of  claim 10 , wherein the anisotropic etching process comprises a radio-frequency (RF) sputtering process. 
   
   
       12 . The method of  claim 1 , wherein the first glue layer comprises titanium (Ti), tantalum (Ta), or tungsten (W). 
   
   
       13 . The method of  claim 3 , wherein the barrier layer comprises titanium nitride, tantalum nitride, or tungsten nitride. 
   
   
       14 . The method of  claim 1 , wherein the substrate further comprises a semiconductor device, and the semiconductor device comprises a conducting region; wherein the conducting region comprises nickel silicide (NiSi), and the conductive structure comprises tungsten. 
   
   
       15 . A plug structure, comprising:
 a substrate;   a dielectric layer disposed on the substrate;   an opening defined in the dielectric layer;   a glue layer covering a sidewall of the opening;   a barrier layer covering a surface of the glue layer; and   a conductive structure filling the opening.   
   
   
       16 . The plug structure of  claim 15 , wherein the barrier layer covers a portion of the substrate at a bottom of the opening. 
   
   
       17 . The plug structure of  claim 15 , wherein the conductive structure contacts a portion of the substrate at a bottom of the opening. 
   
   
       18 . The plug structure of  claim 15 , wherein the conductive structure comprises a seed layer covering a surface of the barrier layer, and a conductive material filling the opening;
 wherein the seed layer and the conductive material comprise copper.   
   
   
       19 . The plug structure of  claim 16 , wherein the substrate comprises a semiconductor device, and the semiconductor device comprises a conducting region; wherein the conducting region comprises nickel silicide, and the conductive structure comprises tungsten. 
   
   
       20 . The plug structure of  claim 15 , wherein the glue layer comprises titanium, tantalum, or tungsten, and the barrier layer comprises titanium nitride, tantalum nitride, or tungsten nitride.