NH4OH-HF Cleaning Fluid Selective Etching for Semiconductor Substrates
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Solution Overview
Problem
Conventional semiconductor substrate cleaning methods fail to selectively remove particulate contaminants and resist residues without damaging oxide films or high melting point metals, leading to re-contamination and performance degradation of semiconductor devices.
Innovation Solution
A semiconductor substrate treating method using a treating fluid with a specific ratio of NH4OH to HF, where 0.30≦X/Y≦0.78 and 0.03≦Y≦6.0, effectively removes contaminants while preserving thermally oxidized films and high melting point metals, ensuring selective etching and enhanced reliability of semiconductor components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If an aqueous solution of dilute hydrofluoric acid is used for cleaning, then oxide removal ability is improved, but selectivity between target oxides and oxide films deteriorates
Solution Approach 1:
The patent changes the chemical composition parameters of the cleaning solution by adding specific concentrations of H2O2 (0.01-10 wt%) and HCl (0.01-10 wt%) to the HF-based solution. This parameter modification enables selective removal of oxide films while preserving metal surfaces, resolving the contradiction between oxide removal ability and selectivity.
2Manufacturing precision
If a cleaning solution with high nitric acid concentration is used for cleaning, then oxidizing action is improved, but metal-based contaminant infiltration into oxide film increases
Solution Approach 1:
The patent changes the oxidizing agent from high concentration nitric acid to a controlled mixture of H2O2 and HF. This parameter change provides sufficient oxidizing action to remove organic contaminants while the controlled concentrations and presence of HF prevent metal-based contaminant infiltration into the oxide film, resolving the contradiction between oxidizing action and contaminant infiltration.
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 allows for efficient removal of contaminants and etching reaction products without unintentionally damaging oxide films or high melting point metals, resulting in improved reliability and performance of semiconductor components.
Implementation Method 1
treating a semiconductor substrate with a treating fluid containing NH4OH and HF wherein the relationships 0.30≦X/Y≦0.78 and 0.03≦Y≦6.0 are satisfied, where X represents a concentration [mol/L] of NH4OH in the treating fluid and Y represents a concentration [mol/L] of HF in the treating fluid
Implementation Method 2
effectively preventing any unintentional removal of an oxide film (in particular, a thermally oxidized film) or other need-to-survive regions composed of Si, poly-Si, high melting point metal or the like
Data Source
AI summary
A semiconductor substrate treating method is disclosed that can selectively remove contaminants or unnecessary substances present on the surface of a semiconductor substrate. Also disclosed are a semiconductor component of enhanced reliability produced by this method and an electronic appliance incorporating the semiconductor component. The semiconductor substrate treating method comprises the step of treating a semiconductor substrate with a treating fluid containing NH4OH and HF wherein the relationships 0.30≦X/Y≦0.78 and 0.03≦Y≦6.0 are satisfied, where X represents a concentration [mol/L] of NH4OH in the treating fluid and Y represents a concentration [mol/L] of HF in the treating fluid. Preferably, the treating fluid is substantially free from H2O2. The semiconductor substrate has a surface, at least a part of which is composed of high melting point metal.