Control of Critical Dimensions of Etched Structures on Semiconductor Wafers

Abstract

A system for real-time monitoring and control of critical dimensions during semiconductor wafer fabrication is provided. The system measures structures in situ, that is, as they are being etched onto a wafer layer.

1 .- 8 . (canceled) 
   
   
       9 . A computer program product comprising a computer usable medium including computer usable program code for real-time monitoring of critical dimensions of structures in a semiconductor wafer fabrication system, said computer program product including: computer usable program code for measuring critical dimensions of a structure as the structure is being etched. 
   
   
       10 . The computer program product of  claim 9 , further comprising:
 computer usable program code, responsive to a determination that a measured critical dimension is within a target limit, for stopping etching of the structure.   
   
   
       11 . The computer program product of  claim 9 , further comprising:
 computer usable program code for applying adaptive process control to control critical dimensions.   
   
   
       12 . The computer program product of  claim 9 , wherein the computer usable program code for measuring critical dimensions of a structure as the structure is being etched comprises at least one of computer usable program code for measuring the critical dimensions with a scanning electron microscope, computer usable program code for using magnetic excitation to induce eddy currents and then analyzing a resulting magnetic field, or computer usable program code for measuring the critical dimensions with a mechanical probe that makes direct electrical contact with the structure. 
   
   
       13 . A semiconductor wafer fabrication system for real-time monitoring of critical dimensions of a structure, comprising:
 measuring mechanism for measuring critical dimensions of a structure as the structure is etched.   
   
   
       14 . The semiconductor wafer fabrication system of  claim 13  further comprising:
 stopping mechanism, responsive to a determination that a measured critical dimension is within a target limit, for stopping etching of the structure.   
   
   
       15 . The semiconductor wafer fabrication system of  claim 13 , further comprising:
 controlling mechanism for applying adaptive process control to control critical dimensions.   
   
   
       16 . The semiconductor wafer fabrication system of  claim 13 , wherein the measuring mechanism comprises at least one of a scanning electron microscope, a mechanical probe that makes direct electrical contact with the structure, or a mechanism for using magnetic excitation to induce eddy currents and then analyzing a resulting magnetic field. 
   
   
       17 . The semiconductor wafer fabrication system of  claim 16 , wherein analyzing a resulting magnetic field comprises analyzing the resulting magnetic field utilizing image recognition software. 
   
   
       18 . The semiconductor wafer fabrication system of  claim 13 , wherein the structure comprises a structure etched on a semiconductor wafer layer. 
   
   
       19 . The semiconductor wafer fabrication system of  claim 18 , wherein the semiconductor wafer layer comprises at least one of a conducting layer, an insulating layer or a semiconducting layer. 
   
   
       20 . The semiconductor wafer fabrication system of  claim 13 , wherein the structure comprises a structure etched on a lithographic mask.