Inorganic Phosphate Doping Composition for Semiconductor Substrates
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor doping methods using phosphoric acid face challenges such as chemical reactivity with polymer binders, instability of phosphorus-containing materials, and undesirable interactions, leading to viscosity changes and segregation issues, as well as the formation of toxic gases.
Innovation Solution
A semiconductor doping method utilizing an inorganic salt of a phosphor-containing acid, such as Al(H2PO4)3, Al(PO3)3, Ca3(PO4)2, or Na4P2O7, dispersed in a solvent, which is more robust and inert, allowing for higher temperature processing and selective doping without interacting with polymer binders, and can be applied as a paste or dispersion for efficient doping of various semiconductor substrates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If phosphoric acid is used for doping, then doping effectiveness is achieved, but chemical reactivity with polymer binders causes viscosity changes and segregation
Solution Approach 1:
The patent changes the chemical form of phosphorus from phosphoric acid to inorganic phosphate salts (such as calcium phosphate, magnesium phosphate, zinc phosphate). This parameter change in chemical composition eliminates the unwanted chemical reactivity with polymer binders while maintaining the doping effectiveness, as the phosphate salts are chemically stable and do not cause viscosity changes or segregation.
Solution Approach 2:
The patent uses inorganic phosphate salts as a stable, non-reactive alternative to phosphoric acid. These salts serve as a reliable doping source without the side effects of chemical reactivity, effectively replacing the problematic phosphoric acid system with a more stable composition that maintains doping functionality without compromising formulation stability.
2Reliability
If phosphoric acid is used for doping, then doping is achieved, but toxic gases are formed during processing
Solution Approach 1:
The patent converts the harmful effect of toxic gas formation into a beneficial outcome by using inorganic phosphate salts that do not produce toxic gases during thermal processing. The phosphate salts decompose into harmless phosphorus-containing species that effectively dope the semiconductor without generating harmful emissions, thus eliminating the toxic gas problem while maintaining doping effectiveness.
3Reliability
If traditional phosphoric acid-based doping is used, then doping is achieved, but interactions with polymer binders cause processing issues
Solution Approach 1:
The patent changes the chemical parameter from phosphoric acid to inorganic phosphate salts, which fundamentally alters the chemical behavior during processing. The phosphate salts are chemically inert toward polymer binders, eliminating the unwanted interactions that complicate manufacturing. This allows for easier processing, better formulation stability, and more reliable manufacturing while maintaining the essential doping function.
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 significantly reduces semiconductor sheet resistance by up to 1000 times and can change the majority carrier type, providing a robust and efficient doping solution that avoids the limitations of traditional phosphoric acid-based methods.
Implementation Method 1
an inorganic salt of a phosphor containing acid dispersed in said solvent
Implementation Method 2
after diffusion in Nitrogen (A) and Nitrogen with 3% of Oxygen (B) ambient
Data Source
AI summary
A composition for doping semiconductor materials, such as silicon, may contain a) a solvent and a) an inorganic salt of a phosphor containing acid dispersed in the solvent. Also disclosed are doping methods using such composition as well as methods of making the doping composition.