Apparatus for Forming Thin Film

Abstract

A shower head having a plurality of ejection holes for supplying an organic metal gas at uniform density to the surface of a substrate and a plurality of ejection holes for supplying an oxidizing gas at uniform density to the same is provided in a reaction furnace of an MOCVD system. A heater for heating the inside to a temperature higher than the thermal decomposition point of the organic metal gas but lower than the film forming temperature is provided in the vicinity of the substrate-side surface of the shower head.

1 . A thin film forming apparatus for forming a thin film containing a metal element on a substrate by chemical vapor deposition which utilizes a thermal decomposition reaction of an organometallic compound, said apparatus comprising:
 means for supplying an organic metal gas to a surface of the substrate at uniform density, the means for supplying gas provided in a reaction chamber and having a plurality of gas ejection holes, and   means for heating the organic metal gas to a temperature higher than a thermal decomposition point of the organic metal gas but lower than a film forming temperature of the organic metal gas, the means for heating being incorporated at a substrate side of said means for supplying gas.   
   
   
       2 . A thin film forming apparatus for forming a thin film containing a metal element on a substrate by chemical vapor deposition which utilizes a thermal decomposition reaction of an organometallic compound, said apparatus comprising:
 means for supplying gases to a surface of the substrate at uniform density, the means for supplying gas provided in a reaction chamber and having a plurality of first gas ejection holes for supplying an organic metal gas to the surface of the substrate, and a plurality of second gas ejection holes for supplying an oxidizing gas to the surface of the substrate, and   means for heating the organic metal gas to a temperature higher than a thermal decomposition point of the organic metal gas but lower than a film forming temperature of the organic metal gas, the means for heating being incorporated around the first gas ejection holes of said means for supplying gas.   
   
   
       3 . A thin film forming apparatus for forming a thin film containing a metal element on a substrate by chemical vapor deposition which utilizes a thermal decomposition reaction of an organometallic compound, said apparatus including means for supplying gas to a surface of the substrate, said means for supplying gas comprising:
 a lower portion including a plurality of gas ejection holes opposing the surface of the substrate and a first heating mechanism which heats the plurality of gas ejection holes to a first temperature, and
 an upper portion including a gas channel which supplies a gas to the plurality of gas ejection holes, and a second heating mechanism which heats the gas channel to a second temperature which is less than the first temperature. 
   
   
   
       4 . A thin film forming apparatus according to  claim 3 , wherein said means for supplying gas further comprises a buffer portion sandwiched between said lower portion and said upper portion, and a heat conductivity of said lower portion is less than a heat conductivity of said upper portion, but greater than a heat conductivity of said buffer portion. 
   
   
       5 . A thin film forming apparatus according to  claim 4 , wherein said upper portion is made of aluminum, said buffer portion comprises an Al 2 O 3  plate, and said second heating mechanism comprises a heater. 
   
   
       6 . A thin film forming apparatus according to  claim 3 , wherein the plurality of gas ejection holes include:
 a plurality of first gas ejection holes for ejecting an organic metal gas, and   a plurality of second gas ejection holes for ejecting an oxidizing gas.   
   
   
       7 . A thin film forming apparatus according to  claim 6 , wherein said lower portion comprises:
 a first plate having the plurality of first and second gas ejection holes, and   a second plate having a first gas channel and a second gas channel, wherein   the plurality of first gas ejection holes are in fluid communication with each other via the first gas channel, the plurality of second gas ejection holes are in fluid communication with each other via the second gas channel, and said first heating mechanism is disposed between said first plate and said second plate.   
   
   
       8 . A thin film forming apparatus according to  claim 7 , wherein said first plate and said second plate are made of an AlN ceramic material, and said first heating mechanism comprises a heater printed on said first plate.