H2O2 Etchant for Flat Recess Profiles in Semiconductor Substrates
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Solution Overview
Problem
Conventional semiconductor processes using ammonia water to etch recesses in MOS transistors result in V-shaped profiles, leading to circuit leakages and diminished electrical quality, especially as device dimensions scale down.
Innovation Solution
A semiconductor process employing an etchant comprising H2O2 or a mixture of NH4OH/H2O2 to form a flat-bottomed recess, which reduces etching rates and prevents circuit leakages by smoothing the recess profile.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If ammonia water is used as an etchant to etch the specific area, then the etching process is simple and cost-effective, but the recess profile becomes V-shaped leading to circuit leakages and diminished electrical quality
Solution Approach 1:
The patent changes the chemical composition parameters of the etchant by incorporating H2O2 (hydrogen peroxide) into the ammonia water solution. This parameter modification transforms the etching chemistry to produce a flat-bottomed recess profile while maintaining the simplicity and cost-effectiveness of wet etching processes.
2Ease of manufacture
If ammonia water is used as an etchant, then the etching cost is low, but the electrical quality of the semiconductor device is diminished due to V-shaped recess profile
Solution Approach 1:
The patent modifies the chemical parameters of the etchant solution by adding H2O2 to ammonia water, which changes the etching mechanism to produce flat-bottomed recesses. This improves electrical quality and prevents circuit leakages while keeping the process cost-effective compared to alternative methods.
3Length of stationary object
If conventional etching methods are used to etch deep recesses, then the etching depth is sufficient, but the recess profile becomes V-shaped causing circuit leakages
Solution Approach 1:
The patent changes the chemical composition parameters of the etchant to include H2O2, which modifies the etching kinetics to achieve both sufficient depth and a flat-bottomed profile. The altered chemistry enables uniform etching across the recess bottom while maintaining adequate etching depth for device requirements.
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 process effectively forms a flat-bottomed recess, enhancing the electrical quality of semiconductor devices by reducing etching time and costs while preventing circuit leakages.
Implementation Method 1
performing an etch process to etch the specific area for forming a recess by using an etchant including H2O2
Data Source
AI summary
A semiconductor process is disclosed. The semiconductor process includes the steps of: providing a substrate having a specific area defined thereon; and performing an etch process by using an etchant comprising H2O2 to etch the specific area for forming a recess.