Semiconductor Conductive Pad Segmentation for Vertical Transistor Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor devices face challenges with punch-through phenomena and increased contact resistance due to dopant penetration during contact and source/drain implantation processes, which affect the on-current and performance of vertical transistors.
Innovation Solution
The semiconductor device incorporates conductive pads with distinct regions, where the contact region does not overlap the transistor in plan view, and the conductive pads are designed to reduce the overlapping area with the upper diffusion layers and pillars, allowing for controlled dopant introduction to prevent punch-through and minimize contact resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If dopant implantation is performed during contact formation, then contact resistance is reduced, but punch-through phenomenon occurs affecting transistor performance
Solution Approach 1:
The conductive pad is divided into two distinct regions: a first region that overlaps the transistor and a second region that does not overlap the transistor. This segmentation allows selective dopant introduction into the second region only, preventing punch-through into the transistor while maintaining low contact resistance through proper doping of the contact region.
Solution Approach 2:
Different regions of the conductive pad are given different doping characteristics. The second region (contact region) receives dopant introduction to reduce contact resistance, while the first region (overlapping the transistor) avoids dopant introduction to prevent punch-through. This local differentiation of doping quality resolves the contradiction between reducing contact resistance and preventing harmful punch-through effects.
2Reliability
If contact overlaps the transistor in plan view, then electrical connection is achieved, but dopant penetration causes punch-through effects
Solution Approach 1:
The conductive pad structure is segmented into overlapping and non-overlapping regions relative to the transistor. The second region is positioned to provide electrical connection without overlapping the transistor, thereby enabling reliable contact while avoiding dopant penetration into the transistor structure.
Solution Approach 2:
The conductive pad acts as an intermediary element between the contact and the transistor. By designing the pad with a second region that does not overlap the transistor, it mediates the electrical connection while preventing direct dopant penetration paths from the contact into the transistor, thus resolving the contradiction between connection and protection.
3Reliability
If dopant is introduced into the conductive pad, then contact resistance decreases, but on-current characteristics deteriorate due to punch-through
Solution Approach 1:
The conductive pad is segmented into regions with different doping requirements. The second region is doped to reduce contact resistance, while the first region remains undoped or lightly doped to maintain proper transistor characteristics and on-current flow, preventing the deterioration caused by punch-through doping.
Solution Approach 2:
Different doping qualities are applied locally within the conductive pad structure. The contact-oriented second region receives heavy doping for low resistance, while the transistor-proximal first region maintains appropriate doping levels for optimal on-current characteristics, thus resolving the contradiction between contact resistance and on-current performance.
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
This design effectively reduces punch-through effects and maintains high on-current characteristics by limiting dopant introduction into the upper diffusion layers and pillars, enhancing the performance and reliability of vertical transistors.
Implementation Method 1
introducing a dopant
Implementation Method 2
The dopant is diffused from the selected part to the conductive pad entirely
Data Source
AI summary
A semiconductor device includes a transistor, a conductive pad, and a contact. The conductive pad is electrically connected to the transistor. The conductive pad may include, but is not limited to, a first region and a second region. The contact is electrically connected to the conductive pad. At least a main part of the first region overlaps the transistor in plan view. At least a main part of the second region does not overlap the transistor in plan view. At least a main part of the contact overlaps the second region in plan view. The at least main part of the contact does not overlap the first region in plan view. The at least main part of the contact does not overlap the transistor in plan view.