Plasma Recess Embedding with Pulsed DC Deposition-Etch Cycles
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Solution Overview
Problem
Conventional methods of embedding a recess in a substrate result in an increasing aspect ratio, making it difficult to accurately fill the recess with a dielectric film due to blocked openings and void generation.
Innovation Solution
A method involving pulsed direct current (DC) voltages is applied to control the potential of the substrate during film formation and etching processes, using a first DC voltage to shape the dielectric film and a second DC voltage to control etching, maintaining the aspect ratio and preventing voids.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional methods of embedding a recess are used, then the recess can be filled with dielectric film, but the aspect ratio increases making it difficult to accurately fill the recess without blocking openings and generating voids
Solution Approach 1:
The patent applies periodic pulsed DC voltages to the substrate during plasma processing. The voltage alternates between different levels (e.g., -100V to -500V) in a controlled cycle, enabling periodic modification of the dielectric film properties. This periodic action allows the film to be deposited and then selectively etched or modified in subsequent pulses, maintaining a consistent aspect ratio while preventing void formation and opening blockage during the embedding process
Solution Approach 2:
The patent changes the DC voltage parameter dynamically during the dielectric film formation process. By adjusting the voltage level and pulse width ratio, the plasma chemistry and ion flux to the substrate are modified, enabling precise control over film deposition rate, density, and etching characteristics. This parameter control maintains a consistent aspect ratio and prevents defects during recess embedding
2Manufacturing precision
If pulsed DC voltage is applied to control substrate potential during film formation and etching, then the aspect ratio is maintained and voids are prevented, but the process complexity increases
Solution Approach 1:
The patent implements dynamic voltage control where the DC voltage applied to the substrate is not static but varies in a controlled manner. The pulsed voltage scheme allows the system to adapt the substrate potential in real-time during different stages of the dielectric film formation process, enabling precise control over film deposition and etching while managing process complexity through automated sequencing
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 method maintains a consistent aspect ratio, allowing for complete embedding of the dielectric film in the recess without blocking the opening, enhancing film accuracy and reducing void generation.
Implementation Method 1
a dielectric film is formed in the recess by a plasma generated from a gas containing a raw material gas supplied into the process chamber
Implementation Method 2
a part of the dielectric film formed in the recess is etched by a plasma generated from a gas containing an etchant gas supplied into the process chamber
Data Source
AI summary
A method of embedding a recess includes: preparing a substrate having a recess on a stage in a process chamber; applying a pulsed first DC voltage to the stage to form a dielectric film in the recess by a plasma generated from a gas containing a raw material gas supplied into the process chamber; applying a pulsed second DC voltage to the stage to etch at least a part of the dielectric film formed in the recess by a plasma generated from a gas containing an etchant gas supplied into the process chamber; and repeating the forming of the dielectric film and the etching of the dielectric film. The first DC voltage is set to a predetermined value, and the second DC voltage is a value different from the first DC voltage and is set to a predetermined value.