Double-Bit Semiconductor Memory Cell With Depth-Matched Separation Channel
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The scaling down of semiconductor devices poses challenges in reducing complexity, improving quality, yield, performance, and reliability, while also requiring enhanced bit capability in memory devices.
Innovation Solution
A semiconductor substrate and device design featuring a first active region with sub-active regions separated by a channel of equal depth to the isolation layer, allowing for a double bit capability and controlled etching processes to maintain the depth of the separation channel, thereby increasing the top surface area and preventing over-etching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the active region is divided into multiple sub-active regions with separation channels, then the bit capability is enhanced, but the manufacturing complexity increases
Solution Approach 1:
The active region is divided into multiple sub-active regions (first sub-active region, second sub-active region, etc.) separated by separation channels. Each sub-active region can be independently controlled, enabling double bit capability while maintaining a systematic and organized structure that manages complexity through functional segmentation.
Solution Approach 2:
The separation channels extend in the depth dimension to substantially the same depth as the isolation layer, creating a three-dimensional separation structure. This vertical dimensionality allows for effective isolation between sub-active regions without increasing lateral footprint, enhancing bit capability within the same planar area.
2Quantity of substance
If the separation channel depth is increased to match isolation layer thickness, then the double bit capability is achieved, but the etching precision requirement increases
Solution Approach 1:
The isolation layer is formed first as a reference structure with a predetermined thickness. The separation channels are then etched to substantially the same depth as the isolation layer thickness, using the isolation layer as a depth reference. This preliminary formation of the isolation layer establishes a natural depth benchmark that simplifies subsequent depth control.
Solution Approach 2:
The separation channel depth is controlled to be substantially equal to the isolation layer thickness, transforming the depth control problem into a relative parameter matching problem. By adjusting the etching depth to match the pre-formed isolation layer depth, manufacturing precision is improved through parameter correspondence rather than absolute depth control.
3Quantity of substance
If the active region area is increased to provide more sub-active regions, then the bit capability is enhanced, but the device area increases
Solution Approach 1:
Instead of increasing lateral area to accommodate more sub-active regions, the patent uses vertical separation channels that extend to the isolation layer depth. This three-dimensional approach allows multiple sub-active regions to be packed more densely in the planar direction without requiring proportional increases in device area, as the separation is achieved vertically rather than laterally.
Solution Approach 2:
The separation channels are nested within the active region structure, with the channels forming void spaces between sub-active regions. This nested configuration allows sub-active regions to be closely packed together with minimal spacing, maximizing the use of available area while maintaining effective separation for double bit capability.
Data Source
AI summary
A semiconductor device and a method of manufacturing a semiconductor device are provided. The semiconductor device includes a semiconductor substrate, a trench, and a word line structure in the trench. The semiconductor substrate has a first active region and an isolation layer. The first active region includes a first sub-active region, a second sub-active region, and a first separation channel separating the first sub-active region from the second sub-active region. The word line structure is adjacent to the first active region and includes a word line insulating layer covering inner side surfaces of the trench, a word line electrode on the word line insulating layer, and a word line capping structure on the word line electrode. A depth of the first separation channel is substantially identical to a thickness of the isolation layer.