Apparatus for single-wafer-processing type CVD

Abstract

A single-wafer-processing type CVD apparatus includes: (a) a reaction chamber including: (i) a susceptor having at least one gas discharge hole to flow a gas into the reaction chamber via a back side and a periphery of the wafer into the reaction chamber; (ii) a showerhead; (iii) an exhaust duct positioned in the vicinity of the showerhead and provided circularly along an inner wall of the reaction chamber; and (iv) a circular separation plate provided coaxially with the exhaust duct to form a clearance with the bottom of the exhaust duct; and (b) a temperature-controlling apparatus for regulating the temperature of the showerhead. The separation plate has a sealing portion to seal a periphery of the susceptor and to separate the reaction chamber from a wafer-handling chamber when the susceptor rises.

1 . A single-wafer-processing type CVD apparatus for forming a film on a semiconductor wafer, comprising: 
 a reaction chamber comprising: (i) a susceptor disposed therein for placing and heating a wafer, wherein at least one gas discharge hole is provided in the susceptor to flow a gas into the reaction chamber via a back side and a periphery of the wafer into the reaction chamber, said susceptor being movable vertically; (ii) a showerhead disposed inside the reaction chamber opposed to and parallel to the susceptor for emitting a jet of reaction gas toward the wafer; (iii) an exhaust duct positioned in the vicinity of the showerhead and provided circularly along a inner wall of the reaction chamber; and (iv) a circular separation plate provided coaxially with the exhaust duct to form a clearance with a bottom of the exhaust duct, said separation plate having a sealing portion to seal a periphery of the susceptor when the susceptor rises, thereby separating the reaction chamber from a wafer-handling chamber configured to be disposed under the reaction chamber; and    a temperature-controlling apparatus for regulating the temperature of the showerhead at a given temperature.    
   
   
       2 . The apparatus as claimed in  claim 1 , wherein the sealing portion is formed with an O-ring.  
   
   
       3 . The apparatus as claimed in  claim 1 , further comprising a circular guard ring disposed to cover a non-deposition area of the periphery of the wafer along an inner circumference of the separation plate.  
   
   
       4 . The apparatus as claimed in  claim 3 , wherein the circular guard ring is disposed at the inner circumference portion of the separation plate to flow a gas from the at least one gas discharge hole to the reaction chamber through a clearance formed between the guard ring and the wafer.  
   
   
       5 . The apparatus as claimed in  claim 1 , wherein said clearance formed between the separation plate and the exhaust duct is adjustable within the range of 0.1 mm to 5 mm by changing a thickness of the separation plate.  
   
   
       6 . The apparatus as claimed in  claim 1 , wherein said given temperature is within the range of 50° C. to 400° C.  
   
   
       7 . The apparatus as claimed in  claim 3 , wherein the guard ring is disposed to position the non-deposition area at the periphery of the wafer within the range of 0.5 mm to 3 mm from a wafer edge.  
   
   
       8 . The apparatus as claimed in  claim 1 , wherein the temperature-controlling apparatus comprises at least one heater disposed near the showerhead, at least one cooling device disposed near the showerhead, a temperature detector, and a temperature controller connected to the heater, the cooling device, and the temperature detector.  
   
   
       9 . The apparatus as claimed in  claim 1 , further comprising a pressure detector for determining a pressure near the wafer by calculating a pressure inside the exhaust duct by using as parameters a clearance between the separation plate and the susceptor and a flow rate of reaction gas.  
   
   
       10 . The apparatus as claimed in  claim 1 , wherein the susceptor has multiple wafer lift pins, and the holes of said lift pins are used as gas discharge holes.  
   
   
       11 . The apparatus as claimed in  claim 1 , wherein the at least one hole is a hole or holes made in the susceptor other than wafer lift pins.  
   
   
       12 . A single-wafer-processing type CVD apparatus for forming a film on a semiconductor wafer, comprising: 
 a reaction chamber comprising: (i) a susceptor disposed therein for placing and heating a wafer, wherein at least one gas discharge hole is provided in the susceptor to flow a gas into the reaction chamber via a periphery of the wafer into the reaction chamber, said susceptor being movable vertically; (ii) a showerhead disposed inside the reaction chamber opposed to and parallel to the susceptor for emitting a jet of reaction gas toward the wafer; (iii) an exhaust duct positioned in the vicinity of the showerhead and provided circularly along a inner wall of the reaction chamber; and (iv) a circular separation plate provided coaxially with the exhaust duct to form a clearance with a bottom of the exhaust duct, said separation plate having a sealing portion to seal a periphery of the susceptor when the susceptor rises, thereby separating the reaction chamber from a wafer-handling chamber configured to be disposed under the reaction chamber, said circular separation plate having an inner circumference inside the sealing portion to cover the at least one gas discharge hole; and    a temperature-controlling apparatus for regulating the temperature of the showerhead at a given temperature.    
   
   
       13 . The apparatus as claimed in  claim 12 , further comprising a circular guard ring disposed along the inner circumference of the separation plate for covering a non-deposition area of the periphery of the wafer, wherein said circular guard ring is provided at the inner circumference portion of the separation plate to flow a gas from the at least one gas discharge hole into the reaction chamber through a clearance between the guard ring and the wafer.