Semiconductor Fin Collapse Prevention via Steam Treatment
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Solution Overview
Problem
In semiconductor device manufacturing, fin-like active areas collapse during dry etching and wet cleaning processes, and substituting wet cleaning with dry cleaning does not fully address the issue of maintaining structural integrity for fine trench isolation as the active areas still collapse after filling with flowable oxide.
Innovation Solution
A method involving forming a lower hard mask layer, a patterned middle hard mask layer, and performing a steam treatment on the substrate with trenches to convert inner surfaces to hydroxyl-terminated groups, facilitating bonding with a polysilazane-based isolation oxide layer to prevent collapse.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If dry etching and wet cleaning processes are used, then manufacturing efficiency is improved, but fin-like active areas collapse
Solution Approach 1:
The method applies steam treatment to the substrate before filling the isolation oxide layer. This preliminary action modifies the surface chemistry of the fin-like active areas by creating hydroxyl-terminated groups, which enhances bonding with the isolation oxide layer and prevents collapse during subsequent processing steps.
Solution Approach 2:
The steam treatment process changes the chemical state of the substrate surface by introducing hydroxyl groups through water vapor exposure. This parameter change in surface chemistry enables stronger bonding between the fin-like active areas and the isolation oxide layer, resolving the collapse issue while maintaining manufacturing efficiency.
2Ease of manufacture
If flowable oxide is used to fill trenches, then isolation structure formation is simplified, but fin-like active areas collapse
Solution Approach 1:
The steam treatment is applied as a preliminary action before filling the trenches with flowable oxide. This treatment modifies the surface chemistry of the fin-like active areas by creating hydroxyl-terminated groups, which enhance bonding with the isolation oxide layer and prevent collapse during the simplified filling process.
Solution Approach 2:
The steam treatment changes the chemical state of the substrate surface by introducing hydroxyl groups through water vapor exposure. This parameter change enables strong bonding between the fin-like active areas and the flowable oxide, allowing the use of simplified isolation structure formation processes without causing collapse.
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 effectively prevents the collapse of highland portions during isolation oxide layer formation, ensuring structural integrity and durability through enhanced bonding with the dielectric material.
Implementation Method 1
performing a steam process to the substrate, performing a steam treatment on the textured substrate having the trenches
Implementation Method 2
each of the inner surfaces has a hydroxyl terminated group after performing the steam process
Implementation Method 3
ensuring structural integrity and durability through enhanced bonding with the dielectric material
Data Source
AI summary
A method of manufacturing a semiconductor structure includes forming a lower hard mask layer on a substrate. A patterned middle hard mask layer is formed on the lower hard mask layer, and the patterned middle hard mask layer has a plurality of openings exposing a portion of the lower hard mask layer. A patterned lower hard mask layer and a textured substrate having a plurality of trenches are formed by etching the exposed portion of the lower hard mask layer and a portion of the substrate under the exposed portion of the lower hard mask layer. A steam treatment is then performed on the textured substrate having the trenchess. An isolation oxide layer is formed to fill the trenches.