Method of forming a silicon nitride layer on a semiconductor wafer

Abstract

The invention provides methods and apparatuses of forming a silicon nitride layer on a semiconductor wafer is located on a susceptor within a semiconductor processing chamber. A carrier gas, a nitrogen source gas, and a silicon source gas are introduced into the semiconductor processing chamber and a semiconductor wafer is exposed to the mixture of gases at a pressure in the chamber in the range of approximately 100 on to 500 Torr.

What is claimed:  
     
         1 . A method of depositing a film of silicon nitride comprising: 
 placing a single substrate in a substrate low pressure chemical vapor deposition chamber;    generating a pressure to from about 100 Torr to about 500 Torr and heating the substrate to a temperature of front about 600° C. to about 800° C., and    providing a gas mixture comprising a silicon source gas and a nitrogen source gas into the chamber.    
     
     
         2 . The method of  claim 1  wherein the gas mixture further includes a carrier gas.  
     
     
         3 . The method of  claim 2  wherein the carrier gas is selected from the group consisting of hydrogen, nitrogen, argon, and helium.  
     
     
         4 . The method of  claim 1  wherein the silicon source gas is selected from the group consisting of silane, disilane and dichlorosilane.  
     
     
         5 . The method of  claim 4  wherein the gas mixture comprises about 230 sccm of dichlorosilane about 1000 sccm of ammonia and about 9000 sccm of hydrogen.  
     
     
         6 . The method of  claim 1  wherein a rate of deposition ranges from approximately 40 Å per minute to about 5,000 Å per minute.  
     
     
         7 . The method of  claim 1 , wherein nitrogen source gas is ammonia.  
     
     
         8 . The method of  claim 1 , wherein the partial pressure of silane is approximately in the range of 0.05 to 5 Torr.  
     
     
         9 . The method of  claim 1 , wherein ammonia has a partial pressure equal to or less than 300 Torr.  
     
     
         10 . A method of forming a silicon nitride layer on a semiconductor wafer, comprising the steps of: 
 locating a semiconductor wafer on a susceptor within a processing chamber;    mixing at least three gases comprising 
 a carrier gas selected from the group consisting of H 2 , N 2 , He, and Ar,  
 a nitrogen source gas, and  
 a silicon source gas;  
   introducing the mixture of gases into the semiconductor processing chamber;    exposing the wafer to the mixture; and    maintaining a pressure in the semiconductor processing chamber in the range of 100 to 500 Torr.    
     
     
         11 . The method of  claim 10  wherein the flow rate of at least one of the gases is 5 liters per minute to 15 liters per minute for a semiconductor processing chamber having a volume in the range of 1 to 9 liters.  
     
     
         12 . The method of  claim 10  wherein the ratio of a flow rate of at least one gas to the volume of a semiconductor processing chamber is 0.7 to 5.  
     
     
         13 . The method of  claim 10  wherein at least two of the gases are at least partially mixed within the semiconductor processing chamber.  
     
     
         14 . The method of  claim 10  wherein the nitrogen source gas is NH 3 .  
     
     
         15 . The method of  claim 10  wherein the silicon source gas is selected from the group consisting of SiH 4 , Si 2 H 6 , and SiH 2 Cl 2 .  
     
     
         16 . The method of  claim 10  further comprising heating the wafer to a temperature of between 600° C. and 800° C. prior to exposing the wafer to the mixture of gases.  
     
     
         17 . A method of forming a silicon nitride layer on a semiconductor wafer, comprising the steps of: 
 locating the semiconductor wafer on a susceptor within a semiconductor processing chamber;    mixing at least two gases in the semiconductor processing chamber selected from the group consisting of 
 a carrier gas,  
 a NH 3  source gas, and  
 a silicon source gas, a silicon source gas selected from the group consisting of 
 exposing the semiconductor wafer to the mixture of gases, and  
 maintaining a pressure in the semiconductor processing chamber in the range of 100 to 500 Torr.  
 
   
     
     
         18 . The method of  claim 17  wherein the flow rate of at least one of the gases is in the range of 1 slm to 12 slm.  
     
     
         19 . The method of  claim 17  further comprising heating the wafer to a temperature of between 600° C. and 900° C. prior to exposing the wafer to the mixture of gases.  
     
     
         20 . The method of  claim 17  wherein the nitride layer forms at a rate in the range of between 40 Å per minute and 5,000 Å per minute.  
     
     
         21 . The method of  claim 17  wherein the carrier gas is selected from the carrier gas selected from the group consisting of H 2 , N 2 , He, and Ar.  
     
     
         22 . A method of depositing films of silicon nitride onto a substrate in a chemical vapor deposition chamber, comprising: 
 (a) supporting a single substrate in the chamber,    (b) adjusting the pressure from about 100 to about 500 Torr and heating the substrate to a temperature from about 600° C. to 800° C.; and    (c) passing a silicon source gas into the chamber.    
     
     
         23 . The method of  claim 22  wherein the nitride layer forms at a rate in the range of between 40 Å per minute and 5,000 Å per minute.  
     
     
         24 . The method of  claim 22  further comprising: 
 removing a gas from the chamber through a pumping plate, the pumping plate has a first stepped portion, a second stepped portion, and a third stepped portion, wherein the third stepped portion has a plurality of holes circumferentially spaced.  
 
     
     
         25 . An apparatus comprising: 
 a chamber configured to house a substrate for processing;    a nitrogen source gas coupled to the chamber;    a silicon source gas coupled to the chamber;    a system controller configured to control the introduction of a nitrogen gas from the nitrogen gas source and a silicon gas from the silicon gas source into the chamber;    at least one pump coupled to the chamber, wherein the pump is capable of creating a pressure greater than 100 Torr;    a memory coupled to the controller comprising a computer-readable medium having a computer-readable program embodied therein for directing operation of the system, the computer-readable program comprising instructions for controlling the nitrogen source gas and the silicon source gas and a pressure in the chamber and the instructions comprise parameters for maintaining a pressure in the range of approximately 100 Torr to approximately 500 Torr in the chamber.    
     
     
         26 . The apparatus of  claim 25  further comprising: 
 a blocker plate coupled to a chamber lid and a perforated face plate wherein the perforated face plate is coupled to a pumping plate;  
 the pumping plate having a first stepped portion, a second stepped portion, and a third stepped portion, wherein the third stepped portion has a plurality of gas holes and the gas holes are substantially circumferentially spaced; and  
 the second stepped portion has two flanges wherein the flanges restrict gas flow.