DRAM Bit Line Mask Structure With Trapezoidal Dielectric Support
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Solution Overview
Problem
In the manufacturing of dynamic random access memory (DRAM) bit line structures, the miniaturization and integration lead to increased fragility and breakage of bit line structures due to the softness of carbon mask layers, resulting in reduced yield and defects.
Innovation Solution
A method involving the formation of a second dielectric layer with a trapezoidal structure, which increases structural strength and prevents bending during etching, allowing the bit line structures to be formed without defects by using this layer as a mask.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If carbon mask layers are used for forming bit line structures, then the manufacturing process can be completed, but the bit line structures are easily broken or bent due to the softness of the carbon mask layers
Solution Approach 1:
The patent uses a composite mask structure consisting of a carbon mask layer combined with a mandrel layer and a sacrificial layer. This composite structure provides the ease of manufacture benefits of carbon while adding structural support through the mandrel and sacrificial layers to prevent breaking or bending during the manufacturing process.
Solution Approach 2:
The mandrel layer acts as an intermediary structural support between the soft carbon mask layer and the substrate. It provides mechanical strength to prevent the carbon mask layer from bending or breaking, while the sacrificial layer serves as a temporary intermediary that facilitates the formation process and is later removed.
2Productivity
If the distance between adjacent memory units is reduced for miniaturization, then the integration is improved, but the bit line structures become more fragile and prone to breaking
Solution Approach 1:
The composite mask structure with mandrel and sacrificial layers provides enhanced mechanical strength that enables smaller feature sizes. The additional structural support allows the bit line structures to maintain integrity even when the distance between adjacent memory units is reduced for higher integration.
Solution Approach 2:
The mask structure is segmented into multiple functional layers (carbon mask layer, mandrel layer, sacrificial layer) that can be independently optimized. This segmentation allows each layer to perform its specific function while collectively providing the strength needed for miniaturized structures.
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 enhances the yield of semiconductor structures by preventing the bit line structures from bending or breaking, thus improving the reliability and integrity of the DRAM manufacturing process.
Implementation Method 1
Part of the initial second mask layer and part of the initial second dielectric layer are etched by taking the photoresist layer as a mask
Implementation Method 2
Part of the initial first mask layer, part of the initial first dielectric layer, part of the initial conductive layer and part of the base are etched by taking the second dielectric layer as a mask
Data Source
AI summary
The application provides a method for manufacturing a semiconductor structure and the semiconductor structure, and relates to the technical field of semiconductors. The method for manufacturing the semiconductor structure includes: providing a base; sequentially stacking an initial conductive layer, an initial first dielectric layer, an initial first mask layer, an initial second dielectric layer, an initial second mask layer and a photoresist layer with a pattern on the base; and etching part of the initial second mask layer, part of the initial second dielectric layer and part of the initial first mask layer by taking the photoresist layer as a mask, so as to form a second dielectric layer with a trapezoidal structure which is of a structure with small top and large bottom.