Multizone Lamphead Control for Substrate Warping and Particle Reduction
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Solution Overview
Problem
Particle contamination during substrate transfer and uneven heating causing substrate warping in epitaxy processes, leading to increased particle deposition on semiconductor substrates.
Innovation Solution
A substrate processing apparatus with a lamp array divided into concentric zones, allowing individual control of lamps to provide differential heating, minimizing substrate warping and controlling thermal gradients.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a substrate is transferred into a processing chamber during epitaxy, then the substrate can be processed, but particles may adhere to the substrate during transfer and flow across the substrate surface
Solution Approach 1:
The substrate is pre-heated on the susceptor before being transferred into the processing chamber. This preliminary heating action ensures the substrate is at the required temperature prior to exposure to process gases, eliminating the need to heat it after transfer and thereby reducing particle contamination risks during transfer operations.
Solution Approach 2:
A susceptor serves as an intermediary component between the substrate and the processing chamber environment. The susceptor provides a controlled thermal environment and a clean transfer interface, mediating the substrate's exposure to potential particle contamination while maintaining necessary processing conditions.
2Temperature
If the susceptor temperature is non-uniform, then heating can be provided to the substrate, but the substrate warps upon initial contact with the susceptor
Solution Approach 1:
The lamp array is divided into multiple zones (inner zone, middle zone, outer zone) with independent temperature control. Each zone can be heated to different temperatures to create a specific thermal profile on the susceptor, allowing localized temperature adjustment to prevent substrate warping while maintaining overall heating requirements.
Solution Approach 2:
The system dynamically adjusts temperature parameters across different susceptor zones by controlling individual lamp zones. By changing temperature distribution parameters rather than using uniform heating, the substrate thermal expansion is controlled to prevent warping while still achieving the necessary heating for epitaxy processing.
3Shape
If the substrate presents a large cross-section within the gas flow path due to warping, then particle deposition on the substrate increases
Solution Approach 1:
The substrate is pre-heated and pre-shaped on the susceptor before being transferred into the processing chamber. This preliminary action ensures the substrate maintains a flat profile with minimal cross-section exposure to gas flow during transfer, reducing particle deposition before the actual epitaxy process begins.
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
Reduces substrate warping and minimizes particle contamination by optimizing substrate orientation relative to gas flow, ensuring uniform heating and reduced particle adherence.
Implementation Method 1
A substrate processing apparatus with a lamp array divided into concentric zones, allowing individual control of lamps to provide differential heating
Implementation Method 2
heating a susceptor in a process chamber using a lamp array comprising a plurality of lamps positioned below the susceptor
Implementation Method 3
flowing a purge gas in a lateral flow path across the susceptor
Implementation Method 4
ensuring uniform heating and reduced particle adherence
Data Source
AI summary
A method and apparatus for processing a semiconductor substrate is described. A substrate processing apparatus is disclosed that includes a process chamber, a substrate support disposed inside the process chamber, a plurality of lamps arranged in a lamphead and positioned proximate to the substrate support, a gas source for providing a purge gas in a lateral flow path across the substrate support, and a controller that differentially adjusts power to individual lamps of the plurality of lamps based on a direction of the flow path.