Diffusion Agent Composition for Semiconductor Boron Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional boron diffusion methods in semiconductor manufacturing, such as the spin coating method, result in high costs, environmental burdens, and difficulties in achieving partial diffusion with uniformity and accuracy, due to out-diffusion and aggregation issues with boron compounds, which complicates the formation of impurity diffusion layers in solar cells.
Innovation Solution
A diffusing agent composition containing a borate ester, a polyhydric alcohol, and an alkoxysilane compound is used to form an impurity diffusion layer on semiconductor substrates, suppressing out-diffusion and aggregation by selectively applying the composition and diffusing boron into the substrate, thereby improving the accuracy and reliability of the impurity diffusion process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional PBF with hydroxyl group-containing polymer compound is used for boron diffusion, then boron can be easily scattered from the coating film to the outside, but out-diffusion occurs and partial diffusion becomes difficult
Solution Approach 1:
The patent changes the chemical parameters of the binder from hydroxyl group-containing polymer compounds to carboxylic acid group-containing polymer compounds. This parameter change prevents out-diffusion of boron while maintaining uniform distribution, enabling accurate partial diffusion without the scattering problems encountered with conventional PBF.
Solution Approach 2:
The patent creates a composite diffusing agent composition by combining carboxylic acid group-containing polymer compounds with specific boron compounds (borates, boron halides, or boron oxides). This composite material achieves both uniform boron distribution and prevention of out-diffusion, resolving the contradiction between manufacturing precision and reliability.
2Manufacturing precision
If spin coating method is used for applying coating liquid, then uniform diffusion is achieved, but amount of coating liquid used is large increasing cost and waste liquid
Solution Approach 1:
The patent applies the coating liquid selectively to only those regions of the silicon substrate where diffusion is required, rather than coating the entire surface. This local quality approach maintains uniform diffusion in the target areas while significantly reducing the total amount of coating liquid used and wasted.
3Adaptability or versatility
If partial diffusion is performed by forming diffusion protection film in advance, then regions with different diffusion carriers can be formed, but number of steps increases
Solution Approach 1:
The patent extracts and eliminates the unnecessary diffusion protection film formation step from the conventional partial diffusion process. By using carboxylic acid group-containing polymer compounds that inherently prevent out-diffusion, the process achieves partial diffusion capability directly through selective coating without requiring additional protection films or extra process steps.
4Manufacturing precision
If boron compounds are dissolved in organic solvent without binder, then aggregation can occur, but highly-concentrated and uniform boron diffusion is required
Solution Approach 1:
The patent introduces carboxylic acid group-containing polymer compounds as intermediary substances that mediate between the boron compounds and the organic solvent. These polymer compounds act as binders that prevent aggregation of boron compounds while maintaining high concentration and uniform distribution, enabling both stability and manufacturing precision.
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 solution enables the formation of impurity diffusion layers with higher accuracy and reliability, reducing costs and environmental impact by minimizing waste and ensuring uniform boron distribution, leading to improved solar cell performance.
Implementation Method 1
diffusing boron of the borate ester (A) included in the diffusing agent composition into the semiconductor substrate
Implementation Method 2
a hydroxyl group-containing polymer compound serving as a binder for boron is decomposed by combustion before diffusing boron
Data Source
AI summary
A diffusion-agent composition including a borate ester (A); a polyhydric alcohol (B) represented by general formula (1); and an alkoxysilane compound (C). In general formula (1), k represents an integer from 0 to 3, m represents an integer of 1 or more, and R2 and R3 each independently represent a hydrogen atom, a hydroxyl group, a C1-5 alkyl group, or a C1-5 hydroxyalkyl group. When there are a plurality of R2s and R3s, the plurality of R2s and R3s may be the same as or different from one another. When k is 2 or more, the plurality of R2s and R3s always include at least one or more hydroxyl groups or C1-5 hydroxyalkyl groups having 1 to 5 carbon atoms. R4 and R5 each independently represent a hydrogen atom or a C1-3 alkyl group.