Film forming apparatus and a barrier film producing method

Abstract

A film forming apparatus is used in a semiconductor manufacturing process and a method for producing a barrier film is used for a semiconductor. When a metallic gas and a reactive gas are alternatively flown, a back-flow preventing gas and an auxiliary gas are flown, the reactive gas and the auxiliary gas are moved with the flow of the back-flow preventing gas, and radicals are produced by being in contact with them to a catalytic material. Since the metallic material gas is not in contact with the catalytic material, the catalytic material is not degraded. A shower plate may be disposed between a radical producing chamber and a reaction chamber, so that the radicals are fed into the reaction chamber through holes. Thus, a barrier film having low resistance and excellent coverage is formed.

1 . A film forming apparatus, comprising:
 a vacuum chamber;   a stage which is disposed in the vacuum chamber and on which an object to be film formed thereon is placed;   a catalytic material disposed away from the stage;   a catalytic material heating device for heating the catalytic material;   a metallic material gas-feeding system to introduce into the vacuum chamber a gas of a metallic material containing a metallic element in the chemical structure;   a reactive gas-feeding system to introduce into the vacuum chamber a reactive gas which reacts with the metallic material gas to produce a metallic compound;   a back-flow preventing gas-feeding system to introduce into the vacuum chamber a back-flow preventing gas which does not interrupt a reaction of the metallic compound; and   a vacuum evacuation system to vacuum evacuate the interior of the vacuum chamber through an exhaust opening arranged near the stage,   wherein an introducing opening to introduce the reactive gas into the vacuum chamber and an introducing opening to introduce the back-flow preventing gas thereinto are arranged farther from the stage as compared to the catalytic material, and an introducing opening to introduce the metallic material gas is arranged between the catalytic material and the stage.   
   
   
       2 . The film forming apparatus according to  claim 1 , further comprising an auxiliary gas-feeding system to introduce into the vacuum chamber an auxiliary gas which reacts with the metallic material gas to produce an intermediate product,
 wherein the metallic compound is produced by a reaction between the reactive gas and the intermediate product.   
   
   
       3 . The film forming apparatus according to  claim 1 , further comprising: a shower plate formed with a plurality of through holes disposed between the catalytic material and the stage; and a radical-producing chamber and a reaction chamber formed in the vacuum chamber,
 wherein the catalytic material and the reactive gas-introducing opening are arranged in the radical-producing chamber, and the stage and the metallic material gas-introducing opening are arranged in the reaction chamber.   
   
   
       4 . The film forming apparatus according to  claim 3 , further comprising an auxiliary gas-feeding system to introduce into the vacuum chamber an auxiliary gas which reacts with the metallic material gas to produce an intermediate product,
 wherein an introducing opening for the auxiliary gas-feeding system is arranged in the radical-producing chamber, and the metallic compound is produced by the reaction between the reactive gas and the intermediate product.   
   
   
       5 . A barrier film producing method for forming a barrier film composed of a metal compound containing a metallic element on a surface of an object to be film formed, comprising the steps of:
 disposing a catalytic material and the object to be film formed inside a vacuum chamber and heating the catalytic material;   introducing step for introducing a gas of a metallic material containing a metallic element in the chemical structure between the catalytic material and the object to be film formed;   producing step for being in contact with a reactive gas to the catalytic material in order to produce radicals of the reactive gas, the reactive gas being adapted to react with the metallic material gas to produce the metallic compound;   repeating the introducing step and the producing step,   wherein a back-flow preventing gas which does not interrupt the production of the metallic compound is introduced into the vacuum chamber, and the metallic material gas and the reactive gas are introduced in a state such that a flow of the back-flow preventing gas is formed, flowing from a side of the catalytic material to a side of the object to be film formed.   
   
   
       6 . The barrier film producing method according to  claim 5 , wherein TiCl 4  is used as the metallic material gas, and one of NH 3  and SiH 4  is used as the reactive gas. 
   
   
       7 . The barrier film producing method according to  claim 5 , wherein an auxiliary gas is introduced into the vacuum chamber, the auxiliary gas is in contact with the catalytic material to produce radicals of the auxiliary gas, the metallic material gas adsorbed on a surface of the object to be film formed is reacted with the radicals of the auxiliary gas in order to produce an intermediate product, and the metallic compound is produced by reacting the produced intermediate product with the reactive gas. 
   
   
       8 . The barrier film producing method according to  claim 7 , wherein an H 2  gas is used as the auxiliary gas. 
   
   
       9 . The barrier film producing method set forth in  claim 5 , further comprising the steps of:
 disposing a shower plate in which a plurality of through holes are formed between the catalytic material and the object to be film formed, thereby forming a radical-producing chamber in which the catalytic material is positioned and a reaction chamber in which the object to be film formed is positioned;   introducing the metallic material gas into the reaction chamber, and introducing the reactive gas and the back-flow preventing gas into the radical-producing chamber; and   vacuum evacuating the gases inside the reaction chamber through an exhaust opening arranged in the reaction chamber.   
   
   
       10 . The barrier film producing method according to  claim 9 , wherein the auxiliary gas is introduced into the radical-producing chamber, radicals of the auxiliary gas are produced by being in contact with the auxiliary gas to the catalytic material, the metallic material gas adsorbed on a surface of the object to be film formed is reacted with the radicals of the auxiliary gas in order to produce an intermediate product, and the metallic compound is produced by reacting the produced intermediate product with the reactive gas. 
   
   
       11 . The barrier film producing method according to  claim 10 , wherein an H 2  gas is used as the auxiliary gas.