Dual-Mode PVD Collimator for Uniform 20nm Feature Coverage
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Solution Overview
Problem
As semiconductor feature sizes decrease, achieving even coverage of sputtered material layers on complex circuits becomes increasingly difficult due to challenges in providing uniform deposition across narrow trench features.
Innovation Solution
A dual-mode physical vapor deposition system that uses a collimator as both a target and a confinement structure, allowing for controlled sputtering and etching processes, with a copper collimator and target, and a control system to manage plasma and power for improved material layer deposition and etching, ensuring better sidewall and bottom coverage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional sputtering deposition is used to form material layers, then material can be deposited on semiconductor wafers, but achieving even coverage on features with decreasing size becomes increasingly difficult
Solution Approach 1:
The system segments the deposition process into two distinct modes: a deposition mode for depositing material layers and a resputtering mode for removing excess material. This segmentation allows precise control over material coverage by first depositing material uniformly and then selectively removing excess, thereby achieving even coverage on features with decreasing size
Solution Approach 2:
The system changes operational parameters by switching between deposition and resputtering modes, controlling plasma power, gas flow rates, and ion bombardment energy. These parameter changes enable precise control over material layer formation and removal, achieving uniform coverage even as feature sizes decrease to 20 nanometers or less
2Adaptability or versatility
If a single chamber is used for both deposition and etching, then process integration is improved, but process control complexity increases
Solution Approach 1:
The system employs dynamic switching between deposition and resputtering modes within the same chamber. By dynamically adjusting plasma power, gas composition, and ion bombardment parameters, the system achieves versatile process integration while maintaining controllable complexity through automated mode transitions and real-time parameter adjustment
3Productivity
If feature size decreases to 20 nanometers or less, then circuit density increases, but achieving even material coverage becomes increasingly difficult
Solution Approach 1:
The system performs preliminary deposition of material layers before conducting resputtering processing. This preliminary action ensures that sufficient material is deposited on all features including those with 20 nanometer or less dimensions, providing a baseline layer that can then be selectively refined through controlled resputtering to achieve even coverage
Solution Approach 2:
The system employs precise parameter changes during resputtering mode, controlling ion bombardment energy, plasma power, and gas flow rates to selectively remove excess material from feature tops while preserving sidewall and bottom coverage. This enables even material coverage on high-density circuits with features at 20 nanometers or less
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 system achieves improved feature coverage, particularly at critical dimensions of 20 nanometers or less, by enabling both deposition and resputtering processes in a single chamber, maintaining profile integrity and enhancing deposition rates through temperature control and plasma management.
Implementation Method 1
In sputtering deposition, a plasma is used to excite ions, typically of a noble gas, to facilitate forceful collisions with a target. Atoms of the target are knocked free by the colliding ions
Implementation Method 2
Some other PVD chambers may also be used in an etching process by exciting ions, noble gases or metal ions, and generating collisions with the layer to be etched on the semiconductor wafer
Data Source
AI summary
Physical vapor deposition systems are disclosed herein. An exemplary physical vapor deposition system includes a target, a collimator, a power source system, and a control system. The power source system is configured to supply power to the collimator and the target. The control system is configured to control the power source system, such that the collimator is bombarded with noble gas ions during a sputtering process and the target is bombarded with metal ions during a re-sputtering process, wherein the collimator functions as a sputtering target during the sputtering process and as the collimator during the re-sputtering process.