Shower Head Vacuum Zones for Wafer Uniformity
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Solution Overview
Problem
The non-uniformity of chemical vapor deposited films and etched areas in semiconductor processing poses challenges due to increased wafer sizes, leading to reduced chip yield and potential damage to device structures, as maintaining within-wafer uniformity becomes increasingly difficult with larger wafers.
Innovation Solution
A shower head apparatus with a vacuum manifold and vacuum system is used to provide uniform distribution of processing gas by applying vacuum in specific zones, ensuring even film thickness and uniformity in CVD and plasma etching processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the wafer size is increased to improve throughput and reduce cost per die, then productivity is improved, but manufacturing precision deteriorates due to difficulty in maintaining within-wafer uniformity
Solution Approach 1:
The shower head is divided into multiple independently controllable zones (e.g., first zone, second zone, third zone) with separate gas supply channels and flow control mechanisms. This segmentation allows differential gas flow distribution across different radial positions, enabling precise control of processing conditions across the entire large wafer surface area.
Solution Approach 2:
Each zone of the shower head is configured with specific gas flow rates, vacuum levels, and processing parameters tailored to its radial position. The first zone (outer region) receives different gas flow and vacuum conditions compared to the second zone (middle region) and third zone (inner region), optimizing uniformity across the wafer by addressing local variations in gas distribution.
2Device complexity
If conventional gas distribution is used in larger wafers, then device complexity is reduced, but manufacturing precision deteriorates due to non-uniform film deposition and etching
Solution Approach 1:
The gas distribution system is segmented into multiple zones with independent flow control, allowing precise regulation of reactant gas flow to different radial regions of the wafer. This ensures uniform film deposition and etching across the entire wafer surface while maintaining a manageable system architecture.
Solution Approach 2:
The system incorporates dynamic control mechanisms including variable flow control valves, adjustable vacuum pumping rates, and real-time monitoring for each zone. These dynamic elements allow the gas distribution system to adapt and optimize processing conditions during operation, achieving high uniformity without excessive complexity.
3Manufacturing precision
If vacuum is applied to specific zones of the shower head, then manufacturing precision is improved through uniform gas distribution, but device complexity increases due to additional vacuum systems and manifolds
Solution Approach 1:
The vacuum system is segmented into multiple independently controllable zones, each with its own vacuum control mechanism. This allows selective application of vacuum to specific shower head zones to optimize gas flow distribution and processing uniformity across different radial regions of the wafer.
Solution Approach 2:
The vacuum manifold system serves multiple functions simultaneously: it provides vacuum pumping, controls gas flow distribution, and enables zone-specific process optimization. By integrating these functions into a unified multi-functional system, the patent achieves improved uniformity without proportionally increasing overall device 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
The solution achieves improved uniformity of film deposition and etching by adjusting vacuum levels in different zones of the shower head, resulting in consistent film thickness across larger semiconductor wafers, thereby enhancing chip yield and reducing structural damage.
Implementation Method 1
at least one vacuum system fluidly coupled to the vacuum manifold of the shower head. The vacuum manifold and the at least one vacuum system are configured to provide vacuum in at least one zone of the shower head
Data Source
AI summary
An apparatus comprises: a shower head having a supply plenum for supplying the gas to the chamber and a vacuum manifold fluidly coupled to the supply plenum; and at least one vacuum system fluidly coupled to the vacuum manifold of the shower head.