Doped Silicon Layer Formation for Conformal Plasma Conversion
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Solution Overview
Problem
Challenges exist in forming high-quality silicon-based and boron-containing films with controlled composition, particularly in non-conformal deposition on high aspect ratio structures, which affect properties such as dielectric constant, adhesion, electromigration, and thermal stability in semiconductor device fabrication.
Innovation Solution
A method involving the formation of amorphous silicon or boron layers on a semiconductor substrate, followed by exposure to a gas plasma flow to convert these layers into doped silicon or boron layers, using remote plasma sources and controlled gas compositions to achieve conformal deposition and desired properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional deposition methods are used to form silicon-based dielectric films, then film formation is achieved, but non-conformal deposition occurs on high aspect ratio structures and composition control is difficult
Solution Approach 1:
The deposition process is segmented into two distinct stages: first forming an amorphous silicon layer, then converting it to a doped silicon layer through plasma exposure. This segmentation allows each stage to be optimized independently for conformality and composition control respectively
Solution Approach 2:
The amorphous silicon layer is formed as a preliminary intermediate layer before the final doped silicon layer is created. This preliminary action enables better conformal coverage on high aspect ratio structures, which is then converted to the desired doped state in a subsequent plasma treatment step
2Manufacturing precision
If doped silicon layers are formed with controlled composition, then film quality is improved, but deposition complexity increases
Solution Approach 1:
The composition control is achieved by segmenting the process into amorphous layer formation followed by plasma-based doping. This allows precise control of dopant concentration and distribution in the second stage without compromising the conformality achieved in the first stage
Solution Approach 2:
The amorphous silicon layer serves as an intermediary between the substrate and the final doped silicon layer. This intermediary enables better control over the final film composition and properties while maintaining process simplicity
3Reliability
If amorphous silicon layer is converted to doped silicon layer through plasma exposure, then step coverage and thermal stability are improved, but process time increases
Solution Approach 1:
The plasma exposure process utilizes controlled parameter changes (gas composition, power, pressure) to optimize the conversion rate from amorphous to doped silicon layer, achieving high thermal stability while minimizing process time through precise parameter optimization
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 enables the formation of doped silicon and boron layers with excellent step coverage, low dielectric constants, and high thermal stability, addressing the challenges of non-conformal deposition and composition control in semiconductor fabrication.
Implementation Method 1
exposing the amorphous silicon layer to a gas plasma flow to convert the amorphous silicon layer to the doped silicon layer
Implementation Method 2
thermally decomposing the silicon-containing precursor to form the amorphous silicon layer
Data Source
AI summary
An amorphous silicon layer or amorphous boron layer can be deposited on a substrate using one or more silicon or boron-containing precursors, respectively. Radical species are provided from a plasma source or from a controlled reaction chamber atmosphere to convert the amorphous silicon layer to a doped silicon layer with composition tunability. An initiation layer is deposited on one or more semiconductor device structures having a dielectric layer over an electrically conductive layer. The initiation layer may be conformally deposited by a CVD-based process and may comprises amorphous silicon, doped silicon, amorphous boron, or doped boron.