Microwave Irradiation Apparatus Independent Temperature Control
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Solution Overview
Problem
Conventional microwave irradiation apparatuses fail to independently control the temperature of semiconductor wafers during processing, as they cannot separate the control of microwave power from wafer temperature, and lack efficient cooling mechanisms while irradiating microwaves.
Innovation Solution
A microwave irradiation apparatus with a vacuum-evacuated processing chamber, a supporting table, processing gas introduction, microwave introduction, a heating unit, a gas cooling unit, and a radiation thermometer for precise temperature control, allowing independent temperature adjustment of the wafer using both heating and cooling units based on real-time temperature measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional microwave irradiation apparatus is used, then microwave processing can be performed, but the temperature of the wafer cannot be controlled independently from microwave power
Solution Approach 1:
The patent separates the temperature control function from microwave power control by introducing independent heating and cooling units. The heating unit (hot plate or heater) and cooling unit (cooling gas supply) operate independently from the microwave generator, allowing separate control of wafer temperature and microwave power. This segmentation enables precise temperature management without being coupled to microwave power levels.
Solution Approach 2:
The patent introduces a temperature measurement unit (infrared thermometer or thermocouple) as an intermediary to monitor wafer temperature in real-time. This measurement feedback is transmitted to the control unit, which then adjusts the heating and cooling units accordingly. The intermediary measurement system enables closed-loop temperature control independent of microwave power settings.
2Productivity
If microwave irradiation is applied to heat the wafer, then processing speed increases, but efficient cooling during irradiation becomes difficult
Solution Approach 1:
The patent implements continuous cooling during microwave irradiation by maintaining a constant supply of cooling gas to the wafer背面 throughout the processing cycle. The cooling gas flow is sustained continuously rather than being interrupted, ensuring that heat removal occurs concurrently with microwave heating. This continuous action allows rapid processing while preventing excessive temperature buildup.
Solution Approach 2:
The patent applies cooling specifically to the wafer背面 (rear surface) while microwave irradiation heats the wafer front surface. This localized cooling approach targets the specific region needing temperature control without interfering with the heating process. The cooling gas is directed precisely at the wafer背面 to create a temperature gradient that enables simultaneous heating and effective cooling.
3Temperature
If heating lamp or heater is used for annealing, then temperature control is achievable, but processing time is extended
Solution Approach 1:
The patent combines microwave irradiation with conventional heating/cooling units to create a hybrid system. The microwave generator provides rapid heating capability while the heating unit and cooling unit maintain precise temperature control. This merging of methods allows the system to achieve both the speed of microwave processing and the temperature precision of conventional methods, reducing overall processing time while maintaining control.
Solution Approach 2:
The patent utilizes the ability to rapidly adjust microwave power levels to change heating rate parameters. By controlling microwave power dynamically in conjunction with the heating and cooling units, the system can achieve rapid temperature increases followed by precise maintenance or reduction, significantly reducing the time required compared to gradual heating with lamps or heaters alone.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables precise temperature control of semiconductor wafers during microwave irradiation, improving processing uniformity and efficiency by allowing independent control of microwave power and temperature, as well as efficient cooling of the wafer during the process.
Implementation Method 1
a microwave introduction unit configured to introduce the microwave into the processing chamber
Implementation Method 2
a radiation thermometer configured to measure a temperature of the target object
Data Source
AI summary
There is provided a microwave irradiation apparatus capable of independently controlling a temperature of a target object while irradiating microwave to the target object. The microwave irradiation apparatus 2 includes a processing chamber 4 configured to be vacuum-evacuated; a supporting table 6 configured to support the target object; a processing gas introduction unit 106 configured to introduce a processing gas into the processing chamber; a microwave introduction unit 72 configured to introduce the microwave into the processing chamber; a heating unit 16 configured to heat the target object; a gas cooling unit 104 configured to cool the target object by a cooling gas; a radiation thermometer 64 configured to measure a temperature of the target object; and a temperature control unit 70 configured to adjust the temperature of the target object by controlling the heating unit and the gas cooling unit based on the temperature measured by the radiation thermometer.