Nitride Surface Restoration for 5nm Etch Selectivity
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Solution Overview
Problem
Existing nitride etching processes face issues with oxide contamination leading to processing anomalies, inefficiencies, and additional costs due to non-selective etching, which affects the quality and efficiency of semiconductor device processing.
Innovation Solution
A method and system for surface modification of nitride-containing substrates using an oxygen-nitrogen layer, involving a surface modification process with specific gases to generate a cleaned nitride structure, which is then etched using a nitride etch process that meets target etch rate and selectivity objectives, particularly in 5 nm or lower technology nodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a conventional nitride etch process is used to achieve high etch rate, then productivity is improved, but oxide contamination causes processing anomalies including tipping or deformation of underlying features and etch stop
Solution Approach 1:
A surface modification process is performed before the nitride etch process to condition the nitride-containing layer surface. This preliminary action removes oxide contamination and prepares the surface, preventing processing anomalies such as tipping or deformation during the subsequent high-rate etch process while maintaining productivity.
2Manufacturing precision
If a selective nitride etch process is used to maintain etch selectivity against oxides and silicon, then manufacturing precision is improved, but oxide contamination still causes etch stop and processing anomalies
Solution Approach 1:
The surface modification process is performed in advance to remove oxide contamination from the nitride-containing layer. This preliminary cleaning action prevents etch stop and processing anomalies during the selective etch process, maintaining both etch selectivity and processing efficiency without requiring additional corrective steps.
3Manufacturing precision
If multiple processing steps are added to clean oxide contamination, then manufacturing precision is improved, but device complexity and processing time increase
Solution Approach 1:
The surface modification process combines multiple functions into a single integrated step: it conditions the nitride-containing layer surface, removes oxide contamination, and prepares the surface for etching. This merged approach achieves the same results as multiple separate cleaning and preparation steps would provide, reducing process complexity and processing time while maintaining manufacturing precision.
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 approach enhances etch selectivity and reduces residue formation, preventing etch stop and deformation, thereby improving processing efficiency, reducing waste, and achieving higher quality semiconductor devices with optimized etching results.
Implementation Method 1
performing a surface modification process on the nitride-containing structure with the oxygen-nitrogen layer using one or more gases, the surface modification process generating a cleaned nitride-containing structure
Implementation Method 2
Reactive Ion Etch (RIE), may be performed in RIE etch systems. RIE etch systems may form a plasma fields for bombarding a surface of a workpiece with ions
Data Source
AI summary
Provided is a method of modifying a surface of a substrate for improved etch selectivity of nitride etching. In an embodiment, the method includes providing a substrate with a nitride-containing structure, the nitride-containing structure having an oxygen-nitrogen layer. The method may also include performing a surface modification process on the nitride-containing structure with the oxygen-nitrogen layer using one or more gases, the surface modification process generating a cleaned nitride-containing structure. Additionally, the method may include performing a nitride etch process using the cleaned nitride-containing structure, wherein the etched nitride-containing structure are included in 5 nm or lower technology nodes, and the nitride etch process meets target etch rate and target etch selectivity, and the cleaned nitride-containing structure meet target residue cleaning objectives.