Movable Disk Aperture for Etch Profile Tuning
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Solution Overview
Problem
Existing substrate processing systems face challenges in achieving uniform etch profiles across substrates, as controlling etch processes from the plasma side alters multiple plasma parameters simultaneously, making it difficult to maintain consistent conditions and tune etch uniformity effectively.
Innovation Solution
A movable disk with adjustable apertures is introduced between the plasma and the substrate, allowing independent control of ion flux without altering plasma properties, enabling precise tuning of etch profiles by blocking or allowing ions to reach specific regions of the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If plasma parameters are adjusted to control etch uniformity, then etch profile control is improved, but plasma stability deteriorates because multiple plasma parameters change simultaneously
Solution Approach 1:
The patent segments the processing chamber into two independent zones: a plasma generation chamber and a substrate processing chamber separated by a grid. This allows independent control of plasma parameters in the first chamber while maintaining stable plasma conditions, and separate control of etch parameters in the second chamber through grid voltage adjustment, thereby resolving the contradiction between etch uniformity control and plasma stability
Solution Approach 2:
The grid acts as an intermediary element between the plasma chamber and substrate chamber. It transmits ion flux control to the substrate while maintaining plasma stability in the source chamber. The grid voltage can be independently adjusted to control ion acceleration and etch uniformity without directly altering plasma generation conditions, thus serving as a mediator that decouples the two control objectives
2Adaptability or versatility
If a movable disk with apertures is added to control ion flux, then etch profile tuning capability is improved, but device complexity increases
Solution Approach 1:
The patent introduces a movable disk with adjustable apertures that can dynamically reposition between different locations (e.g., centered, offset, edge positions) to control ion flux distribution. This dynamic positioning capability provides versatile etch profile tuning (center-to-edge uniformity, selective region etching) while keeping the added complexity manageable through a single movable component rather than multiple fixed structures
Solution Approach 2:
The movable disk adds spatial dimensionality to the control system by introducing radial position as an additional control variable. Instead of only adjusting aperture size, the disk can be positioned at different radial locations to selectively block or transmit ions to different substrate regions, providing versatile etch profile control through positional adjustment rather than requiring multiple complex aperture structures
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 solution provides an independent 'tuning knob' for center-to-edge etch profile tuning, allowing for any desired etch shape without affecting plasma properties, enabling precise control of etch rates and profiles on the substrate.
Implementation Method 1
The grid partitions the processing chamber into a first chamber in which plasma is generated
Implementation Method 2
The first disk blocks ions from the plasma from reaching the substrate
Data Source
AI summary
A processing chamber includes a grid and a first disk. The grid includes a plurality of holes arranged in the processing chamber. The grid partitions the processing chamber into a first chamber in which plasma is generated and a second chamber in which a pedestal is configured to support a substrate. The first disk is arranged in the second chamber. The first disk is movable between the grid and the substrate when supported on the pedestal.