Word Line Trench Corner Rounding for Higher Channel Conductivity
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Solution Overview
Problem
Existing semiconductor manufacturing methods do not effectively create a sufficient height difference between active regions and isolation structures, which limits the contact area and current flow between these regions and the word line (WL), thereby affecting the turn-on speeds and conductivity of channels in the active regions.
Innovation Solution
A method involving corner rounding of active regions and isolation structures exposed by the sidewalls of the WL trench, where the isolation structure is etched to expose active regions, followed by oxidation to form stepped oxide layers, and finally removing these layers to create a first height difference between the active regions and the isolation structure, enhancing the contact area with the WL.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional manufacturing methods are used, then the manufacturing process is simple, but the height difference between active regions and isolation structures is insufficient
Solution Approach 1:
The patent performs preliminary corner rounding on the active regions and isolation structures before forming the word line trench. This preliminary action creates the necessary height difference in advance, allowing the subsequent word line formation to benefit from the pre-established geometric configuration without adding complexity to the main fabrication flow.
Solution Approach 2:
The patent applies corner rounding to create curved surfaces on the active regions and isolation structures. This curvature modification at the corners and edges naturally creates height differences and facilitates better contact geometry with the word line, improving the electrical connection without requiring additional complex structuring steps.
2Reliability
If the contact area between active regions and WL is increased, then the conductivity is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The patent applies corner rounding specifically to the corner regions where contact with the word line occurs, rather than uniformly across entire structures. This partial action concentrates the precision requirements only where they are most critical for conductivity, allowing less stringent control in other areas and reducing overall manufacturing complexity.
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 increases the contact area between active regions and the WL, improving the control of turn-on speeds of channels and enhancing the conductivity and working efficiency of the semiconductor structure.
Implementation Method 1
etching the isolation structure exposed by the sidewalls of the WL trench
Implementation Method 2
performing oxidation on the exposed active regions to convert a second thickness of active regions into oxide layers
Data Source
AI summary
Embodiments of the present application relate to the field of semiconductors, and provide a manufacturing method of a semiconductor structure and a structure thereof. The method of manufacturing a semiconductor structure includes: providing a substrate, active regions and an isolation structure; patterning the active regions and the isolation structure to form a word line trench, sidewalls of the word line trench exposing the active regions and the isolation structure; performing corner rounding at least once on the active regions and the isolation structure exposed by the sidewalls of the word line trench, such that a first height difference is formed between remaining active regions and the isolation structure, wherein the corner rounding includes: etching the isolation structure exposed by the sidewalls of the word line trench, such that a first thickness of the active regions are exposed by the isolation structure.