Pre-heat ring oblong inner edge for deposition uniformity
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Solution Overview
Problem
Existing semiconductor substrate processing technologies face challenges in achieving high throughput due to limitations in controlling gas flow characteristics, leading to turbulent flows and non-uniform film deposition when increasing gas flow rates.
Innovation Solution
The use of a pre-heat ring with an oblong inner edge and varying gap widths around the substrate support in a processing chamber, which directs purge gas flow preferentially through a larger gap near the exhaust outlet, reducing turbulence and concentration dilution, allowing for increased gas flow without affecting deposition uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If gas flow rate is increased to improve substrate throughput, then processing speed increases, but turbulent gas flow and concentration dilution occur resulting in non-uniform film deposition
Solution Approach 1:
The pre-heat ring is segmented into multiple heating zones with independent temperature control, allowing different sections to be optimized for their specific function - some zones prioritize rapid heating for throughput while others maintain uniform temperature for deposition quality
Solution Approach 2:
Different regions of the pre-heat ring are designed with different thermal characteristics - the inner edge has varying radius to create localized heating patterns that compensate for expected temperature variations, ensuring uniform film deposition even at high gas flow rates
2Loss of time
If gas flow rate is increased to reduce cycle time, then processing efficiency improves, but turbulent flow causes non-uniform film deposition
Solution Approach 1:
The pre-heat ring pre-heats the process gas before it reaches the substrate, creating a buffer that allows faster gas flow rates without causing temperature shocks or turbulent flow patterns that would compromise film uniformity
Solution Approach 2:
The system dynamically adjusts gas flow parameters and pre-heat ring temperature parameters to maintain optimal flow conditions - by changing temperature and flow rate parameters in coordination, the system achieves faster cycling while preventing turbulence through controlled parameter transitions
3Ease of manufacture
If pre-heat ring inner edge has constant radius, then manufacturing is simpler, but gas flow control and deposition uniformity are compromised
Solution Approach 1:
The pre-heat ring inner edge is designed with asymmetric geometry - specifically an oblong shape with varying radius - to create non-uniform heating patterns that compensate for heat loss variations across the substrate surface, improving deposition uniformity despite increased manufacturing complexity
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 design enables higher substrate throughput by facilitating quicker transitions between deposition and etch phases while maintaining uniform film deposition, as the pre-heat ring controls gas flow characteristics effectively, reducing turbulence and concentration dilution.
Implementation Method 1
gas pre-heat ring... facilitates controlled gas flow by directing more purge gas through a less restrictive path
Data Source
AI summary
Embodiments of the present invention generally relates to apparatus for use in film depositions. The apparatus generally include pre-heat rings adapted to be positioned in a processing chamber. In one embodiment, a pre-heat ring includes a ring having an inner edge and an outer edge. The outer edge has a constant radius. The inner edge is oblong-shaped and may have a first portion having a constant radius measured from a center of a circle defined by an outer circumference of the ring. A second portion may have a constant radius measured from a location other than the center of the outer circumference. In another embodiment, a processing chamber includes a pre-heat ring positioned around the periphery of a substrate support. The pre-heat ring includes an inner edge having a first portion, a second portion, and one or more linear portions positioned between the first portion and the second portion.