Segmented Wafer Stage Heating for CD Uniformity Control
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Solution Overview
Problem
The critical dimension (CD) uniformity of semiconductor wafers is affected by varying baking temperatures across different areas, leading to deformation and non-uniform film deposition during processes like etching or deposition.
Innovation Solution
A system with a stage having multiple heating lines coupled to a heater is used to control temperature locally on the wafer surface, adjusting the heating temperature and speed to maintain CD uniformity and correct warpage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single uniform heating temperature is applied across the entire wafer, then the heating process is simple and fast, but CD uniformity deteriorates due to varying baking temperatures across different areas
Solution Approach 1:
The heating system is segmented into multiple independent heating zones (first heating zone, second heating zone, third heating zone, fourth heating zone) arranged in a matrix pattern. Each zone can be controlled independently to apply different heating temperatures to different areas of the wafer, thereby achieving CD uniformity while maintaining manageable system complexity through modular segmentation.
Solution Approach 2:
Different regions of the wafer are assigned different heating temperatures based on their specific requirements. The heating zones are configured with varying temperatures (e.g., higher temperature in center zones, lower temperature at edge zones) to compensate for radial temperature gradients and achieve uniform baking conditions across the entire wafer surface, improving CD uniformity through local quality control.
2Manufacturing precision
If multiple heating zones with different temperatures are applied, then CD uniformity is improved, but the heating time increases and processing efficiency deteriorates
Solution Approach 1:
The heating zones are pre-configured with optimized temperature profiles and control parameters before the actual heating process. The control unit is programmed with predetermined temperature sequences and zone activation patterns that enable rapid heating while maintaining CD uniformity, reducing overall heating time through preliminary planning of the thermal process.
Solution Approach 2:
The heating system employs dynamic temperature control where the control unit adjusts the heating power and temperature profiles of different zones in real-time based on feedback. This dynamic adjustment allows the system to optimize heating speed and uniformity simultaneously, adapting the thermal process to minimize total heating time while maintaining CD uniformity across the wafer.
3Speed
If heating temperature is increased to speed up deposition, then deposition speed improves, but warpage and deformation increase due to thermal stress
Solution Approach 1:
The heating zones are configured with differentiated temperature profiles that apply higher temperatures to specific regions where deposition speed is critical, while maintaining lower temperatures in other regions to minimize thermal stress. This localized temperature control enables optimized deposition speed without causing excessive warpage, as each zone's temperature is tuned to balance deposition requirements with warpage prevention.
Solution Approach 2:
The system dynamically adjusts heating temperature parameters and deposition rate parameters in coordination. By changing the temperature profile parameters across different zones and timing the heating cycles, the system optimizes the balance between deposition speed and warpage control. The control unit coordinates temperature parameter changes with deposition process parameters to achieve high speed with minimal warpage.
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 system effectively adjusts CD uniformity and warpage by controlling temperature at specific points, ensuring consistent film deposition quality across the wafer.
Implementation Method 1
The heater is electrically coupled to the processor and configured to control the temperature of the wafer by the stage
Implementation Method 2
The stage is electrically coupled to the processor and being configured to maintain the temperature of the wafer for a predetermined period
Implementation Method 3
The processing reaction chamber body is configured to maintain a low-pressure environment, the system being configured to deposit a film on a wafer disposed in the low-pressure environment
Data Source
AI summary
A system and a method for manufacturing a semiconductor device are provided. The system includes a processor, a processing reaction chamber body, a stage, and a heater. The processing reaction chamber body is configured to maintain a low-pressure environment, the system being configured to deposit a film on a wafer disposed in the low-pressure environment. The stage is configured to support the wafer during deposition of the film. The heater is electrically coupled to the processor and configured to control the temperature of the wafer by the stage. The stage includes an upper surface in contact with the wafer, and wherein the stage includes a plurality of heating lines electrically coupled to the heater for controlling the temperature in at least one area of the upper surface of the stage.