Molybdenum Etching Solution With PEI for Uniform Recess Depth
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Solution Overview
Problem
Existing etching solutions for molybdenum in semiconductor manufacturing often result in uneven etching rates, leading to top-bottom differences in recessing amounts, which can cause device failures and reduce yield.
Innovation Solution
A chemical solution comprising a mixed acid with an inorganic acid, oxidizing agent, carboxylic acid, and water, combined with polyethyleneimine (PEI) at concentrations between 0.05 wt % and 10 wt %, is used for etching molybdenum layers in semiconductor devices, reducing etching rate variations and improving etching uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional etching solutions are used for molybdenum, then etching speed is maintained, but etching uniformity deteriorates due to top-bottom differences in recessing amounts
Solution Approach 1:
The patent modifies the chemical composition parameters of the etching solution by adding polyethyleneimine (PEI) at concentrations of 0.05-10 wt% to the mixed acid system. This parameter change suppresses the top-bottom etching rate difference, achieving uniform recessing amounts across the molybdenum layer thickness without requiring complex process control adjustments.
2Productivity
If high etching rate is achieved, then productivity is improved, but manufacturing precision deteriorates due to uneven etching distribution
Solution Approach 1:
The patent maintains high etching productivity while achieving uniform recessing by optimizing the concentration of PEI in the mixed acid etching solution. The specific concentration range (0.05-10 wt%) enables simultaneous achievement of fast etching rate and uniform etching distribution, resolving the trade-off between productivity and precision.
3Productivity
If conventional mixed acid etching is used, then device manufacturing speed is maintained, but device yield deteriorates due to excessive etching in certain portions
Solution Approach 1:
The patent improves device yield while maintaining manufacturing speed by adjusting the chemical parameters of the etching solution. The addition of PEI at controlled concentrations (0.05-10 wt%) prevents excessive etching at the bottom portion of the molybdenum layer, eliminating the root cause of device failures without slowing down the overall etching process.
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 use of the chemical solution with PEI significantly reduces the top-bottom difference in etching amounts, enhancing the uniformity of molybdenum etching and improving the yield of semiconductor devices by preventing excessive etching of certain portions.
Implementation Method 1
a chemical solution comprises a mixed acid including an inorganic acid, an oxidizing agent, a carboxylic acid, and water; and polyethyleneimine of a concentration in the chemical solution in a range of 0.05 wt % to 10 wt %
Data Source
AI summary
According to one embodiment, a chemical solution comprises a mixed acid including an inorganic acid, an oxidizing agent, a carboxylic acid, and water; and polyethyleneimine of a concentration in the chemical solution in a range of 0.05 wt % to 10 wt %.