Endpoint booster systems

Abstract

An endpoint booster transports an optical signal from inside of a plasma etch chamber through a viewport to an optical cable outside of the plasma etch chamber. The optical signal is analyzed to determine an endpoint of a plasma process. The endpoint booster inhibits process byproducts from accumulating on the viewport during the plasma process, which increases the time between chamber cleanings. The reduction in chamber downtime for cleaning increases production throughput.

1 . An endpoint booster having a front side and a back side, and comprising an aperture configured to channel an endpoint signal from a vacuum etch chamber to a fiber optic cable, the back side of the endpoint booster configured to be installed next to a vacuum side of a viewport window within a wall of the vacuum etch chamber and the front side of the endpoint booster configured to be exposed to an interior of the vacuum etch chamber, the front side including a removal port configured to receive a removal tool thereby permitting an operator to remove the endpoint booster from within the vacuum etch chamber to clean the viewport window. 
     
     
         2 . The endpoint booster of  claim 1  wherein the endpoint booster is configured to increase time between chamber cleanings due to byproduct deposit on the viewport window during semiconductor wafer etching in the vacuum etch chamber. 
     
     
         3 . The endpoint booster of  claim 1  wherein the aperture further includes a first length and a second length such that the front side of the endpoint booster includes a first opening along the first length corresponding to a first diameter and the back side of the endpoint booster includes a second opening along the second length corresponding to a second diameter. 
     
     
         4 . The endpoint booster of  claim 3  wherein the second diameter is larger than the first diameter. 
     
     
         5 . The endpoint booster of  claim 1  wherein the removal port includes a threaded hole that permits the operator to thread the removal tool into the removal port and engage the endpoint booster. 
     
     
         6 . The endpoint booster of  claim 1  wherein the aperture extends from the front side to the back side. 
     
     
         7 . The endpoint booster of  claim 1  wherein the second diameter is approximately 0.50 inches and the first diameter is approximately 0.25 inches. 
     
     
         8 . The endpoint booster of  claim 1  wherein the endpoint booster is cylindrical, an outer diameter of the endpoint booster is approximately 1.5 inches, and a length of the endpoint booster is approximately 0.60 inches. 
     
     
         9 . The endpoint booster of  claim 1  wherein the aperture further includes a first diameter and a second diameter such that the front side of the endpoint booster includes the first diameter and the back side of the endpoint booster the second diameter. 
     
     
         10 . The endpoint booster of  claim 9  wherein a transition between the first diameter and the second diameter occurs gradually along a length of the endpoint booster. 
     
     
         11 . A system for etching a semiconductor wafer, the system comprising:
 a vacuum etch chamber including a viewport window having an atmospheric side and a vacuum side;   a fiber optic cable optically coupled to the atmospheric side of the viewport window, the fiber optic cable configured to receive and transmit an endpoint signal; and   an endpoint booster having a front side and a back side, and comprising an aperture configured to channel an endpoint signal from a vacuum etch chamber to a fiber optic cable, the back side of the endpoint booster configured to be installed next to a vacuum side of a viewport window within a wall of the vacuum etch chamber and the front side of the endpoint booster configured to be exposed to an interior of the vacuum etch chamber, the front side including a removal port configured to receive a removal tool thereby permitting an operator to remove the endpoint booster from within the vacuum etch chamber to clean the viewport window.   
     
     
         12 . The system of  claim 11  wherein the endpoint booster is configured to increase time between chamber cleanings due to byproduct deposit on the viewport window during semiconductor wafer etching in the vacuum etch chamber. 
     
     
         13 . The system of  claim 11  wherein the aperture further includes a first length and a second length such that the front side of the endpoint booster includes a first opening along the first length corresponding to a first diameter and the back side of the endpoint booster includes a second opening along the second length corresponding to a second diameter. 
     
     
         14 . The system of  claim 13  wherein the second diameter is larger than the first diameter. 
     
     
         15 . The system of  claim 11  wherein the removal port includes a threaded hole that permits the operator to thread the removal tool into the removal port and engage the endpoint booster. 
     
     
         16 . The system of  claim 11  wherein the aperture extends from the front side to the back side. 
     
     
         17 . The system of  claim 11  wherein the second diameter is approximately 0.50 inches and the first diameter is approximately 0.25 inches. 
     
     
         18 . The system of  claim 11  wherein the endpoint booster is cylindrical, an outer diameter of the endpoint booster is approximately 1.5 inches, and a length of the endpoint booster is approximately 0.60 inches. 
     
     
         19 . The system of  claim 11  wherein the aperture further includes a first diameter and a second diameter such that the front side of the endpoint booster includes the first diameter and the back side of the endpoint booster the second diameter. 
     
     
         20 . The system of  claim 19  wherein a transition between the first diameter and the second diameter occurs gradually along a length of the endpoint booster.