Boron-Silicon Patterning With Selective Chlorine and Fluorine Etching
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Solution Overview
Problem
Current semiconductor integration processes face challenges in achieving high-quality device production due to issues with material uniformity and selectivity during deposition, etching, and removal of boron or boron-and-silicon materials.
Innovation Solution
The proposed solution involves depositing boron-containing or silicon-and-boron-containing materials on a substrate within a semiconductor processing chamber, followed by etching with chlorine-containing or bromine-containing precursors, and finally removing the remaining material using fluorine-containing precursors. This process includes specific conditions such as maintaining substrate temperatures, adjusting plasma powers, and controlling flow rate ratios of precursors to enhance selectivity and etching efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional deposition and etching processes are used for boron-containing materials, then material removal can be achieved, but selectivity to various exposed materials deteriorates and etching rates are insufficient
Solution Approach 1:
The patent applies parameter changes by optimizing deposition temperature (200-450°C), plasma power levels, and precursor flow rates to achieve both high etching rates and excellent selectivity. The etching process uses specific plasma parameters (power, pressure, gas composition) to selectively remove boron-containing materials at rates exceeding 35 nm/min while maintaining 20:1 selectivity relative to other materials.
Solution Approach 2:
The patent employs composite materials by creating silicon-boron alloys with controlled boron concentrations (1-50 at%). This composite approach enables the material to exhibit enhanced properties that allow for improved etching selectivity and rate, as the specific silicon-boron composition responds differently to fluorine-based etchants compared to pure silicon or other materials.
2Reliability
If thicker mask layers are used to improve pattern transfer, then pattern transfer reliability improves, but the number of processing steps and complexity increases
Solution Approach 1:
The patent changes the material parameters by incorporating boron into the mask layer, which fundamentally alters the etching characteristics. This allows thinner mask layers (reducing complexity) to achieve the same pattern transfer reliability that would otherwise require thicker layers, because the boron-containing material exhibits superior etching selectivity and uniformity.
Solution Approach 2:
The patent extracts the essential function of the mask layer (pattern definition) and achieves it through a material with inherently superior properties. By using boron-containing materials, the mask layer can be thinner while maintaining reliability, effectively removing the need for additional processing steps that would be required with conventional materials.
3Manufacturing precision
If material uniformity is improved for smaller device dimensions, then manufacturing precision improves, but processing time and complexity increase
Solution Approach 1:
The patent optimizes deposition parameters including temperature (200-450°C), pressure, and precursor flow rates to achieve excellent material uniformity across the substrate. The plasma-enhanced chemical vapor deposition process uses controlled parameters to ensure uniform boron incorporation and film thickness, enabling high precision for small device dimensions without requiring excessive processing time.
Solution Approach 2:
The patent employs continuous plasma-enhanced deposition and etching processes that maintain stable reaction conditions throughout the processing. This continuity ensures uniform material properties across the entire substrate area, achieving high manufacturing precision efficiently without requiring multiple discrete processing steps or extended processing times.
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 method improves selectivity to various materials being etched, allows for thinner layers for patterning, reduces risks associated with pattern transfer, and enhances throughput in semiconductor processing by achieving high etching and removal rates while maintaining high selectivity.
Implementation Method 1
forming a plasma of all precursors within the processing region of a semiconductor processing chamber
Implementation Method 2
etching portions of the boron-containing material or the silicon-and-boron-containing material with a chlorine-containing precursor
Implementation Method 3
removing remaining portions of the boron-containing material or the silicon-and-boron-containing material from the substrate with a fluorine-containing precursor
Data Source
AI summary
Exemplary processing methods may include depositing a boron-containing material or a silicon-and-boron-containing material on a substrate disposed within a processing region of a semiconductor processing chamber. The methods may include etching portions of the boron-containing material or the silicon-and-boron-containing material with a chlorine-containing precursor to form one or more features in the substrate. The methods may also include removing remaining portions of the boron-containing material or the silicon-and-boron-containing material from the substrate with a fluorine-containing precursor.