Polysiloxane Etching Additive for Silicon Nitride Selectivity
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Solution Overview
Problem
Current silicon nitride layer etching compositions face challenges in achieving a high etch selectivity ratio with respect to silicon oxide layers, leading to reduced efficiency and increased abnormal growth during semiconductor manufacturing, particularly when used repeatedly or at high temperatures.
Innovation Solution
A polysiloxane-based compound is introduced as an etching additive, formulated with specific functional groups and structures that enhance the etch selectivity ratio and stability of the etching process, combined with phosphoric acid and water to create a silicon nitride layer etching composition that maintains performance over extended use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional etching compositions are used for silicon nitride layer etching, then the etching process can be performed, but the etch selectivity ratio with respect to silicon oxide layers is low and abnormal growth occurs during repeated use
Solution Approach 1:
The patent modifies the chemical composition parameters of the etching solution by introducing a polysiloxane-based compound with specific molecular structure (Formula 1) containing aminoalkyl groups and siloxane backbone. This chemical parameter change enhances the etch selectivity ratio between silicon nitride and silicon oxide layers while improving stability during repeated use, directly resolving the technical contradiction.
Solution Approach 2:
The patent creates a composite etching composition by combining phosphoric acid (main etchant) with a polysiloxane-based compound (additive). This composite formulation synergistically improves both the etch selectivity ratio and the stability during repeated use, addressing the contradiction between manufacturing precision and reliability.
2Productivity
If the etching composition is used repeatedly or at high temperatures, then production efficiency can be maintained, but the etch rate changes significantly and selectivity ratio deteriorates
Solution Approach 1:
The polysiloxane-based compound in the etching composition provides continuous stable performance during repeated use and high-temperature processing. The compound maintains consistent etch rate and selectivity ratio throughout the etching process, enabling continuous production without significant performance degradation, thus resolving the contradiction between productivity and composition stability.
3Manufacturing precision
If the etch selectivity ratio is improved, then abnormal growth is reduced, but the etching process complexity increases
Solution Approach 1:
The polysiloxane-based compound acts as an intermediary substance in the etching composition, mediating between the phosphoric acid and the silicon nitride/oxide layers. It enhances abnormal growth control and selectivity ratio without significantly increasing process complexity, as the compound is simply added to the existing etching solution formulation.
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 polysiloxane-based compound improves the etch selectivity ratio and stability of the silicon nitride layer etching process, reducing abnormal growth and maintaining etch rate consistency even after repeated use, thereby enhancing semiconductor device quality and manufacturing efficiency.
Implementation Method 1
a silicon nitride layer etching composition including: a polysiloxane-based compound
Implementation Method 2
one of R2 and R3 is amino(C1-C20)alkyl
Data Source
AI summary
Provided are a polysiloxane-based compound, a selective etching composition with respect to a silicon nitride layer including the polysiloxane-based compound, and a method of manufacturing a semiconductor device including the etching composition. The silicon nitride layer etching composition including the polysiloxane-based compound may selectively etch the silicon nitride layer relative to a silicon oxide layer, and have a significantly excellent etch selectivity ratio, and a small change in etch rate and a small change in etch selectivity ratio with respect to the silicon nitride layer even when time for using the composition increases or the composition is repeatedly used.