Etchant Composition for Uniform Metal Nitride and Metal Etching
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Solution Overview
Problem
In the wet etching process for semiconductor devices, existing etchant compositions often damage insulation layers and fail to maintain a steady etching capability, particularly when dealing with conductive layers containing metal nitride and metal, leading to uneven etching rates and potential damage to oxide layers.
Innovation Solution
A method using an etchant composition comprising phosphoric acid, nitric acid, and an assistant oxidant, such as an acid ammonium-based or sulfuric acid-based compound, in specific weight percentages, which maintains a consistent etching rate for both metal nitride and metal layers, preventing damage to insulation layers and ensuring uniform etching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional etchant compositions are used, then the etching process can proceed, but the etching capability is not steadily maintained and insulation layers are damaged
Solution Approach 1:
The patent modifies the chemical composition parameters of the etchant by incorporating phosphoric acid (5-20 wt%), nitric acid (5-20 wt%), and assistant oxidants (0.01-10 wt%) in specific proportions. This parameter optimization enables steady etching capability maintenance while preventing insulation layer damage throughout the etching process.
Solution Approach 2:
The etchant composition is formulated as a composite chemical system combining multiple acids and oxidants. This composite approach synergistically enhances etching stability for metal nitride and metal layers while providing selective protection against insulation layer damage.
2Manufacturing precision
If conventional etchants are used, then etching can occur, but uniform etching rate for both metal nitride and metal layers cannot be achieved
Solution Approach 1:
The patent optimizes the concentration parameters of phosphoric acid (5-20 wt%), nitric acid (5-20 wt%), and assistant oxidants (0.01-10 wt%) to achieve substantially equal etching rates for metal nitride and metal layers. This precise parameter control ensures uniform etching across different material compositions.
3Productivity
If extended processing times are used, then complete etching can be achieved, but etching capability deteriorates over time
Solution Approach 1:
The etchant composition is designed to maintain continuous and stable etching capability throughout extended processing times. The balanced formulation of phosphoric acid, nitric acid, and assistant oxidants ensures consistent performance, allowing complete etching of conductive layers while preserving insulation layers even during prolonged exposure.
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 proposed etchant composition ensures a uniform etching rate for conductive layers, maintaining stability over extended processing times without damaging insulation layers or semiconductor materials, resulting in consistently formed conductive patterns with uniform surface characteristics.
Implementation Method 1
an etchant composition that includes phosphoric acid, nitric acid, an assistant oxidant and water
Implementation Method 2
etching the first conductive layer and the second conductive layer using an etchant composition
Data Source
AI summary
The present disclosure herein relates to methods of forming conductive patterns and to methods of manufacturing semiconductor devices using the same. In some embodiments, a method of forming a conductive pattern includes forming a first conductive layer and a second conductive layer on a substrate. The first conductive layer and the second conductive layer may include a metal nitride and a metal, respectively. The first conductive layer and the second conductive layer may be etched using an etchant composition that includes phosphoric acid, nitric acid, an assistant oxidant and a remainder of water. The etchant composition may have substantially the same etching rate for the metal nitride and the metal.