Semiconductor Substrate Diffusion via Thin Silanol Coating
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Solution Overview
Problem
Existing methods for diffusing impurity diffusion ingredients into semiconductor substrates, such as ion implantation and CVD, face challenges with defects and non-uniform distribution, especially on substrates with three-dimensional nano-scale structures like Fin-FETs, leading to performance deterioration and crystal damage.
Innovation Solution
A method involving a diffusion agent composition with an impurity diffusion ingredient and a silicon compound that can hydrolyze to produce a silanol group, applied as a thin coating film of up to 30 nm, allowing uniform diffusion into semiconductor substrates while minimizing defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If ion implantation method is used to diffuse impurity diffusion ingredient into semiconductor substrate, then impurity diffusion can be achieved, but point defects or point defect clusters are formed near the surface of the substrate
Solution Approach 1:
A silicon oxide film is introduced as an intermediary layer between the ion implantation process and the semiconductor substrate. This film acts as a buffer that absorbs implantation damage and prevents direct formation of point defects in the substrate crystal structure, while still allowing impurity diffusion to occur effectively
Solution Approach 2:
The silicon oxide film is formed on the semiconductor substrate surface before ion implantation takes place. This preliminary action prepares the substrate by creating a protective layer that will prevent defect formation during the subsequent implantation process
2Manufacturing precision
If ion implantation method is used to diffuse heavy ions such as As ions into semiconductor substrate, then impurity diffusion can be achieved, but noncrystalline area is formed near the surface of the substrate
Solution Approach 1:
The silicon oxide film serves as a mediator that absorbs the high energy impact of heavy ion implantation, preventing the formation of noncrystalline areas in the substrate. The film acts as a sacrificial layer that protects the crystal structure while still permitting impurity diffusion
Solution Approach 2:
The silicon oxide film is formed beforehand to provide cushioning protection against the damaging effects of heavy ion implantation. This layer absorbs the mechanical stress and energy impact that would otherwise create noncrystalline regions in the substrate
3Manufacturing precision
If ion implantation method is used on semiconductor substrate with three-dimensional structure, then impurity diffusion can be attempted, but uniform implantation into side surface and upper surface of fins and gate is difficult
Solution Approach 1:
The silicon oxide film acts as an intermediary that enables uniform impurity distribution across complex three-dimensional surfaces. The film provides a consistent diffusion pathway that works effectively on vertical sidewalls, horizontal surfaces, and recessed regions alike
Solution Approach 2:
The mechanical ion implantation process is replaced with a chemical diffusion process through the silicon oxide film. This substitution eliminates the directional limitations of ion beam physics and allows uniform impurity distribution through thermal diffusion that is independent of surface geometry
4Manufacturing precision
If CVD method is used to form oxide film with impurity diffusion ingredient, then impurity diffusion can be achieved, but overhang phenomenon causes difficulties in covering whole inner surface of concaves uniformly
Solution Approach 1:
The CVD process is replaced with a spin-coating method that applies the silicon oxide-forming composition uniformly across the substrate surface. This liquid coating method overcomes the overhang effect by allowing the composition to flow and distribute evenly into recessed regions before drying and oxide formation
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 enables effective and uniform impurity diffusion across the entire substrate surface, including inner surfaces of microvoids, reducing defect occurrence and enhancing the performance of semiconductor devices like CMOS image sensors and logic LSI devices.
Implementation Method 1
an Si (silicon) compound (B) that can be hydrolyzed to produce a silanol group
Implementation Method 2
an impurity diffusion ingredient (A) is diffused into a semiconductor substrate through a thin film formed using a diffusion agent composition
Data Source
AI summary
A method for manufacturing a semiconductor substrate. An impurity diffusion ingredient can be diffused well and uniformly from a coating film into a semiconductor substrate by forming a coating film having a thickness of not more than 30 nm on a surface of a semiconductor substrate with a diffusion agent composition containing an impurity diffusion ingredient and a silicon compound that can be hydrolyzed to produce a silanol group.