Apparatus for stably evaporation depositing uniform thin films

Abstract

In a method and apparatus for evaporation depositing uniform thin films, a film is deposited on a substrate of a vacuum environment while maintaining a constant deposition rate. A cover is installed on a wall of the evaporation vessel. When the evaporation material is heated to an evaporation state and the interior of the evaporation vessel reaches a first vapor saturation pressure, the vapor of the evaporation material flows towards a pressure stabilizing chamber. When the pressure stabilizing chamber reaches a second vapor saturation pressure which is smaller than the first vapor saturation pressure, the vacuum environment has a vacuum background pressure which is smaller than the second vapor saturation pressure, so that the evaporation material vapor flows from the pressure stabilizing chamber towards the vacuum environment at constant rate due to the pressure difference, so as to evaporate the substrate.

What is claimed is: 
     
         1 . An apparatus for stably evaporation depositing uniform thin films, provided for evaporation depositing the thin film on a substrate in a vacuum environment system to enhance the uniformity of the thin film by maintaining the deposition rate, and the apparatus comprising:
 at least one evaporation vessel, having an evaporation material contained therein;   at least one cover, covered onto a wall of the evaporation vessel to seal the evaporation vessel, and having a flow hole formed thereon;   at least one heater, for heating the evaporation vessel, so that the interior of the evaporation vessel has a first vapor saturation pressure; and   at least one pressure stabilizing chamber, disposed on a side of the evaporation vessel, and having a nozzle orifice, such that when the evaporation vessel reaches the first vapor saturation pressure, the vapor of the evaporation material flows from the flow hole into the pressure stabilizing chamber, and the interior of the pressure stabilizing chamber has a second vapor saturation pressure, wherein the vacuum environment system has a vacuum background pressure, and the second vapor saturation pressure is smaller than the first vapor saturation pressure and greater than the vacuum background pressure, and the vapor of the evaporation material flows from the nozzle orifice into the vacuum environment system due to the pressure difference between the vacuum background pressure and the second vapor saturation pressure, so as to form a thin film on the substrate at a constant evaporation rate.   
     
     
         2 . The apparatus according to  claim 1 , wherein the evaporation material comes with a plural quantity, and the evaporation materials are disposed at corresponsive spaces inside the evaporation vessel respectively, when each of the evaporation vessel reaches the first vapor saturation pressure, the evaporation materials flow into the pressure stabilizing chambers and mix with one another, and then flow from the nozzle orifice into the vacuum environment system. 
     
     
         3 . The apparatus according to  claim 1 , wherein the evaporation material comes with a plural quantity, and the evaporation materials are disposed at corresponsive spaces inside the evaporation vessel respectively, and the pressure stabilizing chamber also comes with a quantity corresponsive to the quantity of the evaporation vessels, so that when each of the evaporation vessel reaches the first vapor saturation pressure, the evaporation materials flow into the pressure stabilizing chambers, and then flow into the vacuum environment system for mixing and evaporation depositing the substrate. 
     
     
         4 . The apparatus according to  claim 1 , wherein the flow hole and the nozzle orifice are disposed at different axes. 
     
     
         5 . The apparatus according to  claim 4 , wherein the cover is installed at the top of the evaporation vessel.