US 11,942,343 B2
Wafer temperature measurement in an ion implantation system
Chien-Li Chen, Hsin-Chu (TW); and Steven R. Walther, Hsin-Chu (TW)
Assigned to Advanced Ion Beam Technology, Inc., Hsin-Chu (TW)
Filed by Advanced Ion Beam Technology, Inc., Hsin-Chu (TW)
Filed on Jan. 29, 2021, as Appl. No. 17/162,108.
Claims priority of provisional application 62/968,032, filed on Jan. 30, 2020.
Prior Publication US 2021/0242054 A1, Aug. 5, 2021
Int. Cl. H01L 21/67 (2006.01); C23C 14/48 (2006.01); C23C 14/54 (2006.01); G01B 7/06 (2006.01); G01B 11/08 (2006.01); G01K 3/00 (2006.01); G01S 7/481 (2006.01); G01S 17/08 (2006.01); H01L 21/265 (2006.01); H01L 21/324 (2006.01); H01L 21/66 (2006.01)
CPC H01L 21/67248 (2013.01) [C23C 14/48 (2013.01); C23C 14/541 (2013.01); G01B 7/08 (2013.01); G01B 11/08 (2013.01); G01K 3/005 (2013.01); G01S 7/4814 (2013.01); G01S 17/08 (2013.01); H01L 21/265 (2013.01); H01L 21/324 (2013.01); H01L 21/67115 (2013.01); H01L 22/12 (2013.01); H01L 22/26 (2013.01)] 28 Claims
OG exemplary drawing
 
1. A method for controlling wafer temperature in an ion implantation system having an ion implanter and a processing station, the method comprising:
implanting a wafer with ions from an ion beam while maintaining the wafer at a first predetermined temperature within a processing chamber of the ion implanter;
heating the wafer at the processing station with one or more infrared heating lamps;
ceasing to heat the wafer by turning off the one or more infrared heating lamps;
after turning off the one or more infrared heating lamps, at the processing station:
directing a laser beam from a laser source to a predefined location on the wafer; and
detecting, using a monochromator, fluorescent light emitted by the wafer in response to absorbing laser energy of the laser beam;
determining an intensity profile of the detected fluorescent light;
determining a current temperature of the wafer based on one or more characteristics determined from the intensity profile; and
in accordance with the determined current temperature of the wafer satisfying a predetermined condition:
forgoing continuing heating the wafer at the processing station; and
removing the wafer from the processing station.
 
10. A method for controlling wafer temperature in an ion implantation system having an ion implanter and a processing station, the method comprising:
implanting a wafer with ions from an ion beam while maintaining the wafer at a first predetermined temperature within a processing chamber of the ion implanter;
heating or cooling the wafer at the processing station;
after heating or cooling the wafer, at the processing station:
directing a laser beam from a laser source to a predefined location on an edge extending between a top surface of the wafer and a bottom surface of the wafer, wherein a size of a spot of the laser beam is smaller than a thickness of the wafer and wherein the thickness of the wafer is equivalent to a length of the edge;
detecting, using a monochromator, fluorescent light emitted by the wafer in response to absorbing laser energy of the laser beam;
determining an intensity profile of the detected fluorescent light; and
determining a current temperature of the wafer based on one or more characteristics determined from the intensity profile; and
in accordance with the determined current temperature of the wafer satisfying a predetermined condition:
forgoing continuing to heat or cool the wafer at the processing station; and
removing the wafer from the processing station.
 
14. A non-transitory computer-readable storage medium storing one or more programs, the one or more programs comprising instructions, which when executed by one or more processors of a controller of an ion implantation system, cause the controller to:
control an ion implanter of the ion implantation system to implant ions into a wafer while maintaining the wafer at a first predetermined temperature within a processing chamber of the ion implanter;
control a processing station of the ion implantation system to heat the wafer at the processing station with one or more infrared heating lamps;
control a processing station of the ion implantation system to cease heating the wafer by turning off the one or more infrared heating lamps;
after turning off the one or more infrared heating lamps:
control a laser source to direct a laser beam to a predefined location on the wafer; and
obtain, from a monochromator, data representing detected fluorescent light emitted by the wafer in response to absorbing laser energy of the laser beam;
determine an intensity profile of the detected fluorescent light based on the data representing the detected fluorescent light;
determine a current temperature of the wafer based on one or more characteristics determined from the intensity profile; and
in accordance with the determined current temperature of the wafer satisfying a predetermined condition:
control the processing station to forgo continuing heating the wafer at the processing station; and
control the robotic arm to remove the wafer from the processing station.
 
18. An ion implantation system, comprising:
an ion implanter;
a processing station; and
a controller,
wherein the controller comprises memory and one or more processors, and
wherein the memory stores one or more programs, the one or more programs comprising instructions, which when executed by the one or more processors, cause the controller to:
control an ion implanter of the ion implantation system to implant ions into a wafer while maintaining the wafer at a first predetermined temperature within a processing chamber of the ion implanter;
control the processing station of the ion implantation system to heat the wafer at the processing station with one or more infrared heating lamps;
control the processing station of the ion implantation system to cease heating the wafer by turning off the one or more infrared heating lamps;
after turning off the one or more infrared heating lamps:
control a laser source to direct a laser beam to a predefined location on the wafer;
obtain, from a monochromator, data representing detected fluorescent light emitted by the wafer in response to absorbing laser energy of the laser beam;
determine an intensity profile of the detected fluorescent light based on the data representing the detected fluorescent light;
determine a current temperature of the wafer based on one or more characteristics determined from the intensity profile; and
in accordance with the determined current temperature of the wafer satisfying a predetermined condition:
control the processing station to forgo continuing heating the wafer at the processing station; and
control the robotic arm to remove the wafer from the processing station.
 
21. A non-transitory computer-readable storage medium storing one or more programs, the one or more programs comprising instructions, which when executed by one or more processors of a controller of an ion implantation system, cause the controller to:
control an ion implanter of the ion implantation system to implant ions into a wafer while maintaining the wafer at a first predetermined temperature within a processing chamber of the ion implanter;
control a processing station of the ion implantation system to heat or cool the wafer at the processing station;
after heating or cooling the wafer:
control a laser source to direct a laser beam to a predefined location on an edge extending between a top surface of the wafer and a bottom surface of the wafer, wherein a size of a spot of the laser beam is smaller than a thickness of the wafer and wherein the thickness of the wafer is equivalent to a length of the edge;
obtain, from a monochromator, data representing detected fluorescent light emitted by the wafer in response to absorbing laser energy of the laser beam;
determine an intensity profile of the detected fluorescent light based on the data representing the detected fluorescent light;
determine a current temperature of the wafer based on one or more characteristics determined from the intensity profile; and
in accordance with the determined current temperature of the wafer satisfying a predetermined condition:
control the processing station to forgo continuing to heat or cool the wafer at the processing station; and
control the robotic arm to remove the wafer from the processing station.