Wafer Heat Chamber Timing to Stabilize Lamp Annealing Conditions
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Solution Overview
Problem
In semiconductor manufacturing, the existing heat treatment processes using halogen lamps and flash lamps face challenges in maintaining uniform treatment conditions due to prolonged transport times, leading to temperature fluctuations and non-uniform results across wafers, as the chamber rate-determining step is disrupted, causing issues with wafer exchange and temperature stability.
Innovation Solution
A method and apparatus where a transport robot waits for a predetermined time with no substrate in the chamber after removing a heated substrate, then reintroduces a new substrate, with optional light irradiation from halogen lamps to maintain chamber temperature, ensuring uniform treatment conditions even with prolonged transport times.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the transport time of substrates is prolonged to add new processing units, then the transport path can be extended with additional processing, but the chamber rate-determining step is disturbed and wafer exchange cannot be performed, resulting in non-uniform treatment results
Solution Approach 1:
The transport robot preliminarily holds a succeeding substrate in readiness before the preceding substrate is removed from the chamber. This preliminary positioning ensures that wafer exchange can occur without interruption even when transport time is prolonged, maintaining the chamber rate-determining condition and treatment uniformity.
Solution Approach 2:
The system maintains continuous operation by having the transport robot ready with the next substrate during the treatment process. This continuity ensures that the chamber always has a substrate being treated, preventing temperature fluctuations and maintaining uniform treatment conditions across all substrates.
2Reliability
If the treatment time in the chamber is extended to maintain chamber rate-determining status, then wafer exchange can be ensured, but the transport time becomes insufficient and substrate presence in chamber cannot be stabilized
Solution Approach 1:
The transport robot performs preliminary action by holding the succeeding substrate in position during the treatment of the preceding substrate. This allows the robot to immediately exchange substrates when treatment completes, ensuring reliable wafer exchange without requiring extended treatment time.
Solution Approach 2:
The system dynamically adjusts the timing of substrate exchange based on treatment completion. The transport robot transitions from a waiting state to an active exchange state precisely when needed, optimizing both treatment time utilization and transport efficiency without compromising reliability.
3Ease of operation
If no substrate is present in the chamber during transport, then the chamber temperature drops due to lack of heating, but extending transport time to allow substrate preparation causes temperature instability
Solution Approach 1:
The transport robot preliminarily positions the succeeding substrate in the chamber during the treatment of the preceding substrate. This preliminary action reduces the time the chamber is empty, maintaining temperature stability while still allowing necessary substrate preparation and processing.
Solution Approach 2:
The system maintains continuous heating action in the chamber by ensuring a substrate is always present. The transport robot coordinates substrate exchange to occur at treatment completion, eliminating gaps in heating and maintaining stable chamber temperature throughout the process.
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 maintains uniform treatment conditions across substrates by controlling the transport robot's timing and using light irradiation to stabilize the chamber temperature, preventing temperature drops and ensuring consistent processing, even when transport times are extended.
Implementation Method 1
irradiating a first substrate held by a susceptor in a chamber with light from a lamp to heat the first substrate
Data Source
AI summary
A preceding wafer is heat-treated in a treatment chamber. After the completion of the heat treatment, a gate valve is opened, and the preceding wafer is transported out of the treatment chamber. Thereafter, there is a wait of a predetermined time period, with the gate valve closed and halogen lamps on. Light irradiation from the halogen lamps prevents the temperature in the treatment chamber from decreasing during the waiting period. After the waiting period, the halogen lamps turn off, and the gate valve is opened. Then, a succeeding wafer is transported into the treatment chamber. After the gate valve is closed again, the succeeding wafer is heat-treated. The provision of the waiting period makes the treatment conditions of semiconductor wafers uniform even if the transport time of the semiconductor wafers is prolonged.