System for thermal testing a wafer chuck and methods for performing the same
A system for testing a wafer chuck includes: a thermal test vehicle (TTV) that includes a substrate and thermal probes disposed on the substrate; and a vehicle controller configured to control heating of the substrate by the thermal probes and to store temperature data generated by the thermal probes.
1 . A system for detecting a thermal conductivity of a wafer chuck, comprising:
a thermal test vehicle (TTV) comprising:
a substrate configured to contact a wafer chuck; and
thermal probes disposed on the substrate; and
a vehicle controller configured to control heating of the substrate and the wafer chuck by the thermal probes and to store wafer chuck temperature data generated by the thermal probes.
2 . The system of claim 1 , wherein each thermal probe is electrically connected to the vehicle controller and comprises:
a heater; and
temperature sensors.
3 . The system of claim 2 , wherein in each thermal probe:
the heater is annular; and
the temperature sensors comprise:
an inner temperature sensor disposed inside of the heater; and
an outer temperature sensor disposed outside of the heater.
4 . The system of claim 3 , wherein in each thermal probe the inner temperature sensor and the outer temperature sensor are disposed within 5 mm of the heater.
5 . The system of claim 2 , wherein the temperature sensors comprise a thermocouple, a silicon-based sensor, a thermistor, or combinations thereof.
6 . The system of claim 1 , wherein the substrate comprises a semiconductor material, a metal, or a ceramic material.
7 . The system of claim 1 , wherein the vehicle controller comprises:
power contacts electrically connected to heaters of the thermal probes;
sensor contacts electrically connected to temperature sensors of the thermal probes;
a processor configured to control power output from the power contacts to the heaters and to store temperature data provided to the sensor contacts from the temperature sensors;
a switch electrically connected to the processor; and
a display electrically connected to the processor.
8 . The system of claim 1 , further comprising a wafer prober comprising:
a wafer chuck support;
a wafer chuck disposed on the wafer chuck support and having a top surface that is configured to vertically support a wafer;
a cooler configured to provide a cooling fluid to the wafer chuck; and
a prober controller configured to control the wafer prober and process the temperature data stored in the vehicle controller.
9 . The system of claim 8 , wherein the TTV is disposed on the wafer chuck, such that the substrate covers at least 95 % of the upper surface of the wafer chuck.
10 . The system of claim 8 , wherein:
the wafer chuck comprises an internal cooling line; and
the temperature sensors at least partially vertically overlap with the cooling line.
11 . The system of claim 8 , wherein:
the wafer chuck comprises a position sensor; and
one of the temperature sensors vertically overlaps with the position sensor.
12 . A system for detecting a thermal conductivity of a wafer chuck, comprising:
a wafer prober comprising:
a wafer chuck comprising an internal coolant line; and
a cooler configured to circulate a cooling fluid through the internal coolant line;
a thermal test vehicle (TTV) comprising:
a substrate disposed on a top surface of wafer chuck; and
thermal probes configured to heat the substrate and the wafer chuck and generate wafer chuck temperature data, the thermal probes disposed on the substrate such that at least two of the thermal probes at least partially overlap with the internal coolant line in a vertical direction perpendicular to the top surface of the wafer chuck; and
a vehicle controller configured to provide power to the thermal probes and store the wafer chuck temperature data.
13 . The system of claim 12 , wherein the thermal probes are electrically connected to the vehicle controller and comprise:
heaters configured to heat the substrate; and
temperature sensors configured to generate the wafer chuck temperature data.
14 . The system of claim 13 , wherein each thermal probe comprises:
an annular temperature sensor;
an inner temperature sensor disposed inside of the annular temperature sensor; and
an outer temperature sensor disposed outside of the annular temperature sensor.
15 . The system of claim 13 , wherein the vehicle controller comprises:
power contacts electrically connected to the heaters;
sensor contacts electrically connected the temperature sensors; and
a processor configured to control a wattage provided to the heaters and to store temperature data provided to the sensor contacts from the temperature sensors;
a switch electrically connected to the processor; and
a display electrically connected to the processor.
16 . The system of claim 15 , wherein the processor is configured to cycle the wattage supplied to the heaters according to a continuous ramp profile or a pulse ramp profile.
17 . The system of claim 15 , wherein the wafer prober comprises a probe controller configured to process the temperature data to determine thermal properties of the wafer chuck.
18 . A method of detecting a thermal conductivity of a wafer chuck configured to support a semiconductor wafer, the method comprising:
disposing a thermal test vehicle (TTV) on the wafer chuck, the TTV comprising:
a substrate disposed on the top surface of wafer chuck; and
thermal probes disposed on the substrate;
supplying power to the thermal probes to heat the substrate and the wafer chuck;
recording wafer chuck temperature data generated by the thermal probes; and
processing the wafer chuck temperature data to determine thermal properties of the wafer chuck.
19 . The method of claim 18 , wherein the supplying power to the thermal probes comprises cycling a wattage provided to heaters of the thermal probes according to continuous ramp heating profile or a pulse ramp heating profile.
20 . The method of claim 18 , wherein processing the wafer chuck temperature data to determine thermal properties of the wafer chuck comprises measuring thermal probe-to-thermal probe temperature variations.