Semiconductor Word Line Separation Layer for Short Circuit Prevention
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Solution Overview
Problem
In the manufacturing of semiconductor devices with stepped structures, there is a risk of short circuits between conductive word lines due to the deposition of thin films on selective regions, which existing technologies fail to adequately prevent.
Innovation Solution
A substrate processing method involving the stacking of insulating and sacrificial layers, generation of a stair structure, and the use of separation layers between conductive word lines, along with selective densification and etching techniques to prevent shorts, including the deposition of a silicon oxide layer on the side walls and replacement with metal to act as word lines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thin films are deposited on stepped structures using conventional methods, then film coverage is achieved, but short circuits between conductive word lines occur
Solution Approach 1:
A separation layer is introduced as an intermediary insulating layer between adjacent conductive word lines on the same level. This separation layer prevents electrical shorts while allowing the thin film deposition process to proceed, thus resolving the contradiction between reliability and ease of manufacture.
Solution Approach 2:
The insulating layer is selectively formed only in regions where word lines are in close proximity and short circuit risk exists. This localized approach provides electrical insulation precisely where needed without requiring complete re-engineering of the deposition process.
2Reliability
If separation layers are added to prevent shorts, then electrical reliability improves, but device structure becomes more complex
Solution Approach 1:
The separation layer is integrated with the existing insulating layer formation process. By combining the separation layer function with the standard insulating layer deposition, the patent adds reliability without proportionally increasing device complexity.
Solution Approach 2:
The separation layer is formed in advance during the insulating layer deposition process, before subsequent manufacturing steps. This preliminary action prevents shorts from the outset rather than requiring additional corrective steps later.
3Manufacturing precision
If conventional deposition is used on stepped structures, then manufacturing process remains simple, but selective region deposition control is insufficient
Solution Approach 1:
The insulating layer is deposited with varying thickness across different regions of the stepped structure. Thinner regions are formed where word lines require separation, while thicker regions provide adequate insulation elsewhere. This local quality variation achieves precise selective region deposition.
Solution Approach 2:
Deposition parameters such as deposition rate, plasma power, and cycle timing are adjusted to control the thickness and distribution of the insulating layer across different regions of the stepped structure, enabling precise selective region deposition.
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 electrical shorts between conductive word lines by using separation layers and controlled etching and deposition techniques, ensuring reliable and stable semiconductor device performance.
Implementation Method 1
depositing an insulating layer (e.g., a silicon oxide (SiO) layer and/or a silicon nitride (SiN) layer) on the substrate based on plasma-enhanced atomic layer deposition (PEALD)
Implementation Method 2
generating a stair structure by etching the stack structures
Data Source
AI summary
A substrate processing method includes stacking a plurality of stack structures each including an insulating layer and a sacrificial layer, on one another. The method also includes generating a stair structure by etching the stack structures and generating a separation layer on a side surface of the stair structure. The method further includes removing the sacrificial layer and generating conductive word line structures in spaces from which the sacrificial layer is removed. The separation layer is provided between the conductive word line structures.