Remote Plasma Source Pulsing for Anisotropic 3D Etch Profiles
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Solution Overview
Problem
The semiconductor industry faces challenges in achieving accurate, precise, and profile-controlled patterning of features at atomic scale dimensions, particularly in 3D semiconductor devices like FinFET and 3D NAND memory, due to complexities in plasma etch processing.
Innovation Solution
The method involves using a remote source (RS) mediated plasma etch processing with advanced pulse control, where radicals are generated in a RS chamber and transported to a plasma processing chamber, enabling conformal radical coverage and improving ion verticality and anisotropy of the etch process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional plasma etch processing is used, then the etch process can be performed, but the anisotropy and profile control are insufficient at atomic scale dimensions
Solution Approach 1:
The plasma etch processing is segmented into two distinct chambers: a remote source chamber for generating radicals and a processing chamber for etching. This segmentation allows independent optimization of radical generation and ion bombardment processes, achieving superior profile control and anisotropy while managing process complexity through modular design.
Solution Approach 2:
The radical generation function is extracted from the processing chamber and placed in a remote source chamber. This extraction enables conformal radical coverage on substrate surfaces without the complications of simultaneous ion bombardment, improving profile control and anisotropy for 3D structures.
2Manufacturing precision
If high radical density is maintained for conformal coverage, then profile control improves, but critical dimension loss increases
Solution Approach 1:
The system provides different local conditions: high radical density in the remote source chamber for conformal coverage, and controlled ion bombardment in the processing chamber for anisotropic etching. This local quality differentiation enables profile control while minimizing critical dimension loss through precise spatial control of reactive species.
Solution Approach 2:
The system uses periodic pulsing of radical generation and ion bombardment to achieve conformal coverage while controlling etch rate. By alternating between radical supply phases and ion bombardment phases, the system maintains profile control and reduces critical dimension loss through temporal separation of functions.
3Productivity
If advanced pulse control is implemented, then etch rate and anisotropy improve, but device complexity increases
Solution Approach 1:
The system implements dynamic pulse control of radical generation and ion bombardment, adjusting timing and duration to optimize etch rate and anisotropy. This dynamic control enables high productivity through enhanced etch rates while managing complexity through automated pulse sequencing and process integration.
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 approach enhances the anisotropy and etch rate of plasma etch processing, reduces critical dimension loss, and mitigates aspect ratio dependent etching (ARDE), while maintaining high radical density and ion verticality.
Implementation Method 1
generating a first plasma from a first gas flowing into a first chamber by applying a first power pulse to a first electrode located in the first chamber
Implementation Method 2
applying a plurality of second power pulses to a second electrode located in the second chamber to generate a second plasma in the second chamber from a second gas flowing into the second chamber
Implementation Method 3
applying a plurality of third power pulses to a third electrode located in the second chamber to accelerate ions of the second plasma
Implementation Method 4
providing radicals from the first chamber into the second chamber; the first chamber being pressurized higher than the second chamber
Data Source
AI summary
A plasma processing system includes a remote source chamber, a plenum chamber, a plasma process chamber, and a substrate holder disposed within the plasma process chamber. The remote source chamber is configured to contain a remote plasma generated from a first gas within the remote source chamber. The remote plasma includes radicals. The plenum chamber is includes a radical ballast region bounded by a bottom wall and sidewalls. The plenum chamber is configured to receive the radicals from the remote source chamber. The plasma process chamber is configured to receive the radicals through the sidewalls of the plenum chamber as well as to contain a process plasma generated from a second gas within the plasma process chamber. The substrate holder is configured to support a substrate to be processed using the process plasma in the presence of the radicals.