Semiconductor Furnace Temperature Control to Suppress Overshoot
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Solution Overview
Problem
Existing temperature control methods in semiconductor manufacturing apparatuses experience overshoot and prolonged recovery times when a substrate is inserted into a furnace, leading to inefficient temperature convergence.
Innovation Solution
A temperature control method that utilizes a prediction model to adjust heater supply power, updating future target temperatures based on current and final target temperatures, convergence ramp rates, and designated time to suppress overshoot and enhance convergence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a substrate retainer is inserted into the furnace during temperature control, then the substrate can be processed, but the inner temperature of the furnace drops and causes overshoot when returning to original temperature
Solution Approach 1:
The control device predicts future temperature values based on current temperature and historical data before the substrate retainer is fully inserted. This preliminary prediction allows the system to prepare compensatory heating actions in advance, preventing temperature drops and overshoot when the substrate retainer enters the furnace. The prediction model calculates expected temperature changes and adjusts heater power proactively rather than reactively.
Solution Approach 2:
The system implements a feedback mechanism where the actual temperature is continuously measured and compared with predicted temperature values. The control device uses this feedback to adjust the heater power supply dynamically, ensuring the temperature follows the target trajectory even when the substrate retainer is inserted. The feedback loop compensates for deviations caused by substrate insertion in real-time.
2Reliability
If conventional PID control is used to maintain furnace temperature, then temperature can be stabilized, but recovery time becomes longer when temperature drops due to substrate insertion
Solution Approach 1:
Instead of waiting for temperature to drop and then recovering, the system performs preliminary temperature prediction and applies compensatory heating before the full temperature drop occurs. This reduces the magnitude and duration of temperature excursions, thereby shortening recovery time while maintaining stability.
Solution Approach 2:
The control system transitions from static PID parameters to dynamic prediction-based control. The control device continuously updates heater power based on predicted temperature trajectories and actual measurements, allowing adaptive response to substrate insertion events. This dynamic adjustment enables faster recovery by intensifying heating when needed and reducing it when temperature stabilizes.
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
The method quickly converges to target temperatures by predicting and adjusting heater power, reducing overshoot and shortening recovery times in the furnace.
Implementation Method 1
an amount of electric power of the heater of heating the inside of the furnace is controlled
Data Source
AI summary
According to one aspect of the technique of the present disclosure, there is provided a temperature control method including: (a) controlling a current heater supply power such that a predicted temperature column calculated according to a prediction model stored in advance approaches a future target temperature column, wherein the future target temperature column is updated in accordance with a current temperature, a final target temperature and one of a temperature convergence ramp rate and a designated temperature convergence time.