FinFET Doping Layer Barrier for Leakage Current Control
Solution Overview
Problem
Current semiconductor technologies face challenges in effectively reducing circuit element dimensions and increasing integration while preventing leakage currents in three-dimensional multiple-gate structures like FinFETs, where doping layers of different conductivity types are not optimally disposed on fin portions to control channel electrically.
Innovation Solution
A semiconductor structure is developed with doping layers of different conductivity types disposed on the sidewalls of a fin portion, where a first doping layer of one conductivity type covers the sidewall and bottom surface of a second doping layer of opposite conductivity type, with additional dielectric layers forming a barrier to prevent leakage currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If doping layers of different conductivity types are disposed on the sidewall of a fin portion, then the control of the FinFET channel is enhanced and leakage currents are prevented, but the device complexity increases
Solution Approach 1:
The doping structure is segmented into multiple distinct layers: a first doping layer of first conductivity type disposed on the sidewall of the fin portion, and a second doping layer of second conductivity type disposed between the fin portion and the first doping layer. This segmentation allows each layer to independently perform its function in controlling the channel and preventing leakage currents.
Solution Approach 2:
Different regions of the semiconductor device are assigned different doping characteristics. The first doping layer with first conductivity type is placed on the sidewall to provide one type of electrical control, while the second doping layer with opposite conductivity type is placed between the fin and first doping layer to prevent leakage currents locally at the interface region.
2Reliability
If the first doping layer covers the sidewall and bottom surface of the second doping layer, then leakage current prevention is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The second doping layer is formed first on the sidewall of the fin portion, and then the first doping layer is formed to cover both the sidewall and bottom surface of the second doping layer. This preliminary action of forming the second layer first establishes a foundation that guides the subsequent formation of the first layer, ensuring proper coverage and positioning.
Solution Approach 2:
The second doping layer is nested within the structure formed by the first doping layer. The first doping layer completely covers the second doping layer on the sidewall and extends to cover its bottom surface, creating a nested configuration where one doping layer is embedded within the protective envelope of the other.
Data Source
AI summary
A semiconductor structure and a manufacturing method thereof are provided. The semiconductor structure includes a substrate, a first dielectric layer, a first doping layer of a first conductivity type, and a second doping layer of a second conductivity type. The substrate has a fin portion. The first dielectric layer is disposed on the substrate and surrounds the fin portion. The first doping layer of the first conductivity type is disposed on the first dielectric layer and is located on two opposite sidewalls of the fin portion. The second doping layer of the second conductivity type is disposed on the two opposite sidewalls of the fin portion and is located between the fin portion and the first doping layer. The first doping layer covers a sidewall and a bottom surface of the second doping layer.