Flash Lamp Annealing Dummy Wafer Stabilization
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Solution Overview
Problem
In flash lamp annealing processes for semiconductor wafer treatment, the temperature stabilization of in-chamber structures, such as the susceptor, can lead to inefficiencies due to the need for dummy running, which requires multiple dummy wafers and increases processing time, affecting the temperature history and efficiency of product wafer treatment.
Innovation Solution
A method and apparatus that initiate heat treatment of a dummy wafer upon receiving an advance notice signal for a product wafer's arrival, allowing for immediate temperature stabilization of in-chamber structures using a dedicated dummy carrier and load port, minimizing downtime and maintaining treatment efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If dummy running is performed to stabilize the temperature of in-chamber structures, then temperature stability is improved, but processing time increases
Solution Approach 1:
The system performs preliminary temperature stabilization of in-chamber structures by detecting when a carrier is loaded into the chamber and automatically initiating a heating process using the loaded carrier itself as the heat treatment target, thereby eliminating the need for separate dummy wafers and reducing overall processing time while ensuring temperature stability for subsequent product wafers
Solution Approach 2:
The loaded carrier serves a dual function: it acts as both the container for wafers and as the target for temperature stabilization. The system uses the carrier's own thermal mass to stabilize the chamber temperature, making the carrier self-serving for both transport and thermal conditioning purposes
2Stability of the object's composition
If multiple dummy wafers are used for temperature stabilization, then temperature history consistency is improved, but device complexity increases
Solution Approach 1:
The invention extracts the temperature stabilization function from the traditional multi-dummy-wafer process and consolidates it into a single automated control sequence that uses the loaded carrier itself, thereby simplifying the process while maintaining temperature history consistency
Solution Approach 2:
The system changes the operational parameters by using the loaded carrier as the heat treatment target instead of requiring separate dummy wafers, and by triggering the stabilization process based on carrier detection rather than manual intervention, thereby reducing process complexity
3Reliability
If dummy running is performed before product wafer treatment, then treatment efficiency is maintained, but productivity decreases
Solution Approach 1:
The system performs temperature stabilization as a preliminary action immediately when the carrier is loaded, overlapping this with the time before product wafer treatment begins, thereby maintaining treatment efficiency without sacrificing overall productivity
Solution Approach 2:
The temperature stabilization process is initiated continuously upon carrier detection without interrupting the overall production flow, ensuring that the useful action of temperature preparation occurs during otherwise idle time, thereby maintaining both treatment efficiency and productivity
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
This approach enables effective use of time before product wafers arrive, ensuring consistent temperature history and minimizing treatment efficiency losses by allowing immediate dummy treatment, thus stabilizing the in-chamber structures efficiently.
Implementation Method 1
The xenon flash lamps have a spectral distribution of radiation ranging from ultraviolet to near-infrared regions. The wavelength of light emitted from the xenon flash lamps is shorter than that of light emitted from conventional halogen lamps, and approximately coincides with a fundamental absorption band of a silicon semiconductor wafer. Thus, when a semiconductor wafer is irradiated with a flash of light emitted from the xenon flash lamps, the temperature of the semiconductor wafer can be raised rapidly
Data Source
AI summary
Product recipes in which a treatment procedure and treatment conditions of heat treatment of product wafers are specified are created timely. Dummy recipes in which a treatment procedure and treatment conditions of heat treatment of dummy wafers are specified are also created. Each of the product recipes and a corresponding one of the dummy recipes are stored in association with each other. Dummy treatment of a dummy wafer starts when a controller receives an advance notice signal indicating that product wafers will arrive at a heat treatment apparatus. The dummy wafers are stored in a dummy carrier permanently installed on a load port exclusive to the dummy carrier. The dummy treatment is performed in accordance with a dummy recipe associated with a product recipe corresponding to the product wafers scheduled to arrive at the heat treatment apparatus.