Devices and methods for measuring wafer characteristics during semiconductor wafer polishing
A system and method of measuring a change in thickness of a layer of material disposed on a wafer while polishing the layer. Light is directed at the surface of the wafer from an indwelling optical sensor disposed within a polishing pad and data signals are wireless transmitted to a control system.
1 . A system for measuring a change in wafer characteristics while said wafer is polished, said system comprising:
a polishing pad suitable for polishing the wafer;
a light source disposed within the pad;
a light detector disposed within the pad;
a wireless transmitter disposed within the pad; and
a sensor control system disposed within the pad, said sensor control system operably connected to the light source, the light detector and the wireless transmitter.
2 . The system of claim 1 further comprising a wireless receiver disposed within the pad operably connected to the sensor control system.
3 . The system of claim 1 further comprising a power supply operably connected to the sensor control system.
4 . The system of claim 1 further a force transducer disposed within the pad operably connected to the sensor control system.
5 . The system of claim 1 further comprising an accelerometer disposed within the pad operably connected to the sensor control system.
6 . The system of claim 1 further comprising a pH sensor disposed within the pad operably connected to the sensor control system.
7 . The system of claim 1 further comprising a thermocouple disposed within the pad operably connected to the sensor control system.
8 . The system of claim 1 further comprising a CMP control system in wireless communication with the sensor control system, said CMP control system operably connected to a CMP tool and capable of controlling a rate of polishing of the CMP tool when a predetermined wavelength of light is measured.
9 . A system for measuring a change in wafer characteristics while said wafer is polished, said system comprising:
a polishing pad suitable for polishing the layer; and
a sensor assembly disposed within the polishing pad, said sensor assembly comprising:
a housing;
a sensor control system disposed within the housing;
a light source disposed within the housing and operably connected to the control system;
a light detector disposed within the housing and operably connected to the sensor control system; and
a wireless transmitter disposed within the housing and operably connected to the sensor control system.
10 . The system of claim 9 wherein the sensor assembly is removably coupled to the pad.
11 . The system of claim 9 further comprising a wireless receiver disposed within the housing and operably connected to the sensor control system.
12 . The system of claim 9 further comprising a power supply operably connected to the sensor assembly.
13 . The system of claim 9 wherein the housing is in the shape of a disk.
14 . The system of claim 9 wherein the housing is in the shape of a spool.
15 . The system of claim 9 wherein the sensor assembly further comprises a force transducer disposed within the housing and operably connected to the sensor control system.
16 . The system of claim 9 wherein the sensor assembly further comprises an accelerometer disposed within the housing and operably connected to the sensor control system.
17 . The system of claim 9 wherein the sensor assembly further comprises a pH sensor disposed within the housing and operably connected to the sensor control system.
18 . The system of claim 9 wherein the sensor assembly further comprises a thermocouple disposed within the housing and operably connected to the sensor control system.
19 . The system of claim 9 further comprising a CMP control system in wireless communication with the sensor assembly and operably connected to a CMP tool, said CMP control system capable of controlling a rate of polishing of the CMP tool when a predetermined wavelength of light is measured.
20 . The system of claim 9 wherein the sensor assembly is characterized by an outer surface facing outwardly from the pad, said outer surface being substantially flush with an outer surface of the polishing pad.
21 . A sensor for use in a CMP polishing pad, said system comprising:
an optically transparent housing;
a sensor control system disposed within the housing;
a light source disposed within the housing and operably connected to the control system;
a light detector disposed within the housing and operably connected to the control system; and
a wireless transmitter disposed within the housing and operably connected to the control system;
wherein the housing is capable of being releasably coupled to a CMP polishing pad.
22 . The sensor assembly of claim 21 further comprising a wireless receiver disposed within the housing and operably connected to the sensor control system.
23 . The sensor assembly of claim 21 a power supply operably connected to the sensor assembly.
24 . The sensor assembly of claim 21 wherein the housing is in the shape of a disk.
25 . The sensor assembly of claim 21 wherein the housing is in the shape of a spool.
26 . The sensor assembly of claim 21 further comprising a force transducer disposed within the housing and operably connected to the control system.
27 . The sensor assembly of claim 21 further comprising an accelerometer disposed within the housing and operably connected to the sensor control system.
28 . The sensor assembly of claim 21 further comprising a pH sensor disposed within the housing and operably connected to the sensor control system.
29 . The sensor assembly of claim 21 wherein further comprising a thermocouple disposed within the housing and operably connected to the sensor control system.
30 . The sensor assembly of claim 12 wherein the power source comprises a battery.
31 - 39 . (canceled)