Furnace Thermal Zone Control for Semiconductor Thin Film Uniformity
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Solution Overview
Problem
Existing semiconductor wafer processing methods face challenges in achieving uniform thin film deposition and maintaining consistent film properties across multiple wafers, leading to inconsistencies in film thickness and physical properties.
Innovation Solution
A furnace system with a heating assembly that controls temperature zones along the reaction chamber, allowing for gradual adjustment of heat output from sidewall heaters to optimize temperature distribution and uniformity during thin film deposition and purging processes, ensuring consistent film formation and properties across semiconductor wafers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a furnace system with heating assembly is used to control temperature zones, then temperature uniformity during thin film deposition is improved, but device complexity increases
Solution Approach 1:
The reaction chamber is divided into multiple temperature zones (first end thermal zone, middle thermal zone, second end thermal zone) with independent temperature control. Each zone can be controlled separately to achieve uniform thin film deposition across all wafers while maintaining manageable system complexity through modular zone control.
Solution Approach 2:
Different thermal modes are applied to different zones based on local requirements. During material supply, the second end thermal zone is heated to higher temperature to compensate for material concentration depletion. During purging, temperature distribution is reversed. This localized quality control achieves uniform film properties without requiring uniform high complexity throughout the entire system.
2Manufacturing precision
If thermal modes are adjusted during material supply and purging, then thin film deposition uniformity is improved, but process time increases
Solution Approach 1:
The furnace operates in periodic thermal modes that switch between material supply phase and purging phase. During material supply, thermal mode first is applied; during purging, thermal mode second is applied. This periodic switching optimizes deposition uniformity while maintaining efficient process cycling, preventing excessive process time extension.
Solution Approach 2:
Temperature parameters are dynamically changed between phases: during material supply, the second end thermal zone temperature is increased to compensate for decreasing material concentration; during purging, the temperature distribution is reversed. These parameter changes are timed to coincide with phase transitions, achieving uniform deposition without adding excessive process time.
3Manufacturing precision
If temperature in second end thermal zone is increased during material supply, then thin film deposition uniformity is improved, but energy consumption increases
Solution Approach 1:
The temperature in the second end thermal zone is proactively increased during material supply to preemptively compensate for the anticipated depletion of processing material concentration. This preliminary anti-action prevents deposition non-uniformity before it occurs, avoiding the need for even higher energy consumption during later stages to correct thickness variations.
Solution Approach 2:
The elevated temperature in the second end thermal zone is applied periodically only during the material supply phase, not continuously. During the purging phase, the temperature distribution is reversed or reduced. This periodic application reduces overall energy consumption compared to maintaining high temperature throughout the entire process cycle.
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 enhances the uniformity of thin film thickness and improves the critical dimension control of semiconductor wafers by up to 0.3%, reducing die failure rates and improving known good die testing uniformity.
Implementation Method 1
A furnace system with a heating assembly that controls temperature zones along the reaction chamber, allowing for gradual adjustment of heat output from sidewall heaters to optimize temperature distribution and uniformity during thin film deposition
Implementation Method 2
CVD is a reactive process used to produce or deposit thin films of material on the wafer including, but not limited to, metals, silicon dioxide, tungsten, silicon nitride, silicon oxynitride, and various dielectrics
Data Source
AI summary
A method for processing semiconductor wafers in a furnace is provided. The method includes forming a thin film on each of the semiconductor wafers in a furnace. The furnace includes a first end thermal zone, a middle thermal zone and a second end thermal zone arranged in sequence. The method further includes controlling the temperature of the furnace in a first thermal mode during the formation of the thin film. The method also includes supplying a purging gas into the furnace after the formation of the thin film. In addition, the method includes controlling the temperature of the furnace in a second thermal mode during the supply of the purging gas. The temperature distributions of the furnace are different in the first and second thermal modes.