Semiconductor Gate Structure for Edge Leakage Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor devices face challenges in reducing leakage current and maintaining threshold voltage due to impurity absorption in the insulating layer edge regions during manufacturing, leading to increased element-to-element pitch and reduced chip area efficiency.
Innovation Solution
The semiconductor device incorporates an insulating layer and a semiconductor layer disposed between the insulating layer and the conductive layer, forming a hammerhead-type planar shape for the semiconductor layer, which increases channel length in edge regions and reduces leakage current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional insulating layer structure is used, then manufacturing is simpler, but leakage current increases due to impurity absorption in edge regions
Solution Approach 1:
The insulating layer is segmented into a first insulating layer and a second insulating layer with different dielectric constants. The first insulating layer has a higher dielectric constant and is positioned adjacent to the transistor, while the second insulating layer has a lower dielectric constant. This segmentation allows the structure to maintain electrical performance while reducing impurity absorption effects in edge regions, thereby reducing leakage current without significantly increasing manufacturing complexity.
Solution Approach 2:
Different regions of the insulating layer structure are assigned different dielectric properties. The first insulating layer with higher dielectric constant is strategically placed where strong electrical field control is needed (adjacent to transistor), while the second insulating layer with lower dielectric constant is placed in edge regions where impurity absorption is problematic. This local differentiation optimizes both electrical performance and leakage current reduction.
2Productivity
If element pitch is reduced to increase chip area efficiency, then chip area efficiency improves, but leakage current increases due to shorter channel length
Solution Approach 1:
The dual-layer insulating structure applies local quality differentiation where the first insulating layer with higher dielectric constant provides enhanced electrical control in critical transistor regions, enabling shorter channel lengths without excessive leakage. The second insulating layer with lower dielectric constant manages edge region effects. This allows pitch reduction for better chip area efficiency while maintaining leakage control through localized dielectric property optimization.
Solution Approach 2:
The invention changes the dielectric constant parameter of the insulating layer by using two different insulating materials with different dielectric constants. This parameter change enables the insulating structure to maintain effective electrical control at reduced pitch dimensions, allowing chip area efficiency improvement without sacrificing leakage current control that would normally require longer channel lengths.
3Manufacturing precision
If impurity absorption in insulating layer edge regions is prevented, then threshold voltage is maintained, but manufacturing precision requirements increase
Solution Approach 1:
The insulating structure uses composite materials with different dielectric constants to address impurity absorption issues. The first insulating layer with higher dielectric constant provides better electrical control to maintain threshold voltage, while the combination with the second insulating layer reduces edge effects where impurity absorption occurs. This composite approach maintains threshold voltage without requiring extremely tight manufacturing precision on single-layer structures.
Solution Approach 2:
The dual-layer insulating structure provides beforehand cushioning against impurity absorption effects. By strategically placing the first insulating layer with higher dielectric constant adjacent to the transistor and the second insulating layer with lower dielectric constant in edge regions, the structure preemptively compensates for impurity absorption that would otherwise occur during manufacturing, thereby maintaining threshold voltage without requiring excessive manufacturing precision.
Data Source
AI summary
A semiconductor device includes: a semiconductor substrate; a transistor formed on the semiconductor substrate; a first insulating layer adjacent to the transistor in a first direction along a main surface of the semiconductor substrate, the first insulating layer being formed toward an inside of the semiconductor substrate; a first conductive layer connected to a gate of the transistor, a part of the first conductive layer being opposed to the first insulating layer; a second insulating layer disposed between the first insulating layer and the first conductive layer; and a first semiconductor layer disposed between the second insulating layer and the first conductive layer.