Plasma enhanced atomic layer deposition (PEALD) equipment and method of forming a conducting thin film using the same thereof

Abstract

A plasma enhanced atomic layer deposition (PEALD) apparatus and a method of forming a conductive thin film using the same are disclosed. According to the present invention of a PEALD apparatus and a method, a process gas inlet lube and a process gas outlet tube are installed symmetrically and concentrically with respect to a substrate, thereby allowing the process gas to flow uniformly, evenly and smoothly over the substrate, thereby forming a thin film uniformly over the substrate. A uniquely designed showerhead assembly provides not only reduces the volume of the reactor space, but also allows the process gases to flow uniformly, evenly and smoothly throughout the reation space area and reduces the volume of the reaction space, and the smaller volume makes it easier and fast to change the process gases for sequential and repeated process operation.

1 . An atomic layer deposition (ALD) apparatus for depositing a film on a substrate, the apparatus comprising: 
 an outer chamber;    an inner chamber within the outer chamber, the inner chamber comprising: 
 a flange configured to define an opening between the inner chamber and the outer chamber;  
 a substrate carrier for supporting the substrate, the substrate carrier configured to seal the opening with a substrate supported thereon within the second chamber;  
 a showerhead assembly in fluid communication with source gases for ALD; and  
 a gas outlet tube for discharging gases from the inner chamber; and  
   a control system configured to alternately supply the source gases into the inner chamber,    wherein the apparatus is configured to flow inert gas through the outer chamber while the film is being deposited in the inner chamber.    
   
   
       2 . The apparatus of  claim 1 , wherein the inner chamber further comprises a radio frequency (RF) connection terminal for generating plasma.  
   
   
       3 .- 6 . (canceled)  
   
   
       7 . The apparatus of  claim 1 , wherein the substrate carrier is configured to move the substrate away from the opening and towards the opening.  
   
   
       8 . The apparatus of  claim 1 , wherein the inner chamber further comprises a showerhead insulating wall surrounding at least a portion of the showerhead assembly.  
   
   
       9 . The apparatus of  claim 1 , wherein the inner chamber further comprises a plasma generation barrier wall between the showerhead insulating wall and an inner chamber wall, the inner chamber wall at least partially defining the inner chamber, the plasma generation barrier wall having the same electrical potential as the inner chamber wall.  
   
   
       10 . The apparatus of  claim 9 , wherein the inner chamber further comprises a gap between the plasma generation barrier wall and the showerhead insulating wall.  
   
   
       11 . The apparatus of  claim 1 , wherein the outer chamber comprises an inert gas inlet tube for providing an inert gas into the outer chamber.  
   
   
       12 . The apparatus of  claim 11 , wherein the outer chamber comprises an inert gas outlet tube for removing an inert gas from the outer chamber.  
   
   
       13 . The apparatus of  claim 1 , wherein the apparatus is configured to continuously supply an inert gas into the outer chamber while the film is being deposited on the substrate in the inner chamber.  
   
   
       14 . A plasma enhanced atomic layer deposition (PEALD) apparatus for depositing a film on a substrate, the apparatus comprising: 
 a first chamber having an inert gas inlet tube and an inert gas outlet tube; and    a second chamber within the first chamber, the second chamber comprising: 
 a substrate support structure configured to seal an opening of the second chamber;  
 a gas inlet tube for supplying gases into the second chamber;  
 a gas outlet tube for discharging gases from the second chamber; and  
 a radio frequency (RF) connection terminal for generating plasma in the second chamber.  
   
   
   
       15 . The apparatus of  claim 14 , wherein the second chamber further comprises a showerhead assembly in fluid communication with the gas inlet tube of the second chamber.  
   
   
       16 . The apparatus of  claim 15 , wherein the showerhead assembly is in electrical contact with the RF connection terminal.  
   
   
       17 . The apparatus of  claim 14 , wherein the first chamber is configured to be continuously purged with an inert gas while the film is being deposited on the substrate in the second chamber.  
   
   
       18 . The apparatus of  claim 14 , further comprising a control system configured to control plasma generation and alternately supply gases into the second chamber.  
   
   
       19 . A plasma-enhanced atomic layer deposition (PEALD) method for forming a film on a substrate, the method comprising: 
 loading the substrate into a first chamber, the first chamber disposed within a second chamber, the first chamber having a gas inlet tube and a gas outlet tube;    supplying a source gas containing a desired metallic component into the first chamber through the gas inlet tube and exhausting the source gas through the gas outlet tube;    supplying a purge gas into the first chamber through the gas inlet tube to remove excess source gas from the first chamber;    generating a plasma for a period of time while continuously supplying the purge gas;    ceasing generating the plasma while continuing to supply the purge gas; and    repeating supplying the source gas, supplying the purge gas and generating the plasma in a plurality of cycles.    
   
   
       20 . The PEALD method of  claim 19 , wherein the source gas includes titanium tetrachloride (TiCl 4 ).  
   
   
       21 . The PEALD method of  claim 19 , wherein the purge gas comprises hydrogen (H 2 ).  
   
   
       22 . The PEALD method of  claim 19 , wherein the first chamber is defined in part by a gas injection assembly and a reactor wall, the gas injection assembly having a gas injection face and an adjacent side wall, the gas injection assembly protruding from the reactor wall such that a space is formed between the side wall of the gas injection assembly and the reactor wall.  
   
   
       23 . The PEALD method of  claim 22 , wherein exhausting the source gas through the gas outlet tube comprises directing the source gas to the space between the sidewall and the reactor wall.  
   
   
       24 . The PEALD method of  claim 22 , wherein the gas injection assembly comprises a showerhead assembly.  
   
   
       25 . The PEALD method of  claim 19 , wherein the gas inlet tube comprises a micro-feeding tube assembly, the micro-feeding tube assembly comprising a plurality of parallel tubes, and wherein the source gas is supplied through the gas inlet tube and subsequently through the micro-feeding tube assembly.  
   
   
       26 . The PEALD method of  claim 19 , wherein during supplying the source gas and generating the plasma, an inert gas is provided in the second chamber.  
   
   
       27 . The apparatus of  claim 1 , wherein the inner chamber further comprises a plasma generation suppressing structure mounted between the gas inlet tube and the showerhead assembly, the plasma generation suppressing structure configured to flow gas from the gas inlet tube to the showerhead assembly.  
   
   
       28 . The apparatus of  claim 27 , wherein the plasma generation suppressing structure comprises a micro-feeding tube assembly.  
   
   
       29 . The apparatus of  claim 28 , wherein the micro-feeding tube assembly comprises a plurality of parallel tubes.  
   
   
       30 . The apparatus of  claim 29 , wherein each of the plurality of parallel tubes is formed of an electrically insulating material.  
   
   
       31 . The apparatus of  claim 29 , wherein each of the plurality of parallel tubes has a diameter and a length sufficient to prevent plasma generation within the micro-feeding tube assembly.  
   
   
       32 . The apparatus of  claim 1 , wherein the apparatus is configured to maintain a higher pressure of inert gas directed into the outer chamber relative to the pressure of gas within the inner chamber.