Backgate Doped SOI Semiconductor Structure for Threshold Voltage Control
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Solution Overview
Problem
Conventional semiconductor technologies face challenges in adjusting threshold voltage and reducing device size due to short channel effects and increased footprint caused by additional contacts and wirings in SOI-CMOS integration.
Innovation Solution
A semiconductor structure with a backgate region formed by doping the additional SOI layer, combined with shallow trench isolation and buried oxide layers, allows for capacitive coupling to adjust threshold voltage, reducing device size and manufacturing complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional SOI-CMOS integration is used to achieve smaller gate pitch and improved efficiency, then manufacturing cost is lowered, but additional contacts and wirings are required which increase device footprint
Solution Approach 1:
The invention merges the backgate contact function with the source/drain contact structure. The backgate region is formed by doping a portion of the additional SOI layer beneath the source or drain region, allowing the same contact structure to serve both source/drain and backgate functions, thereby eliminating separate backgate contacts and reducing device footprint
Solution Approach 2:
The source/drain contact structure is designed to serve multiple functions: it provides electrical connection to the source/drain regions and simultaneously serves as the backgate contact. This multi-functional design eliminates the need for separate backgate contacts and wirings, reducing the overall device footprint while maintaining all necessary electrical connections
2Reliability
If grounded SOI layer is formed below ultra-thin buried oxide layer to adjust threshold voltage and suppress short channel effects, then device performance is improved, but additional contacts and wirings are required which increase device footprint
Solution Approach 1:
The invention combines the backgate doping region with the source/drain contact formation process. The backgate region is created by doping the additional SOI layer in the same areas where source/drain contacts are formed, merging two separate structures into one and eliminating the need for additional backgate contacts and wirings
Solution Approach 2:
The invention extracts the backgate function from a separate structural element and integrates it into the existing source/drain contact structure. By doping the additional SOI layer beneath the source/drain regions, the backgate functionality is achieved without requiring separate contacts or wirings, thereby reducing device complexity
3Productivity
If smaller gate pitch is used to achieve improved efficiency and lowered manufacture cost, then manufacturing cost is reduced, but short channel effects are caused which deteriorate device performance
Solution Approach 1:
The invention applies local doping to the additional SOI layer beneath the source/drain regions to create a backgate effect. This localized modification of electrical properties in specific regions allows for threshold voltage control and short channel effect suppression without changing the overall gate pitch or device geometry
Solution Approach 2:
The invention changes the electrical parameters of the additional SOI layer through doping, creating a backgate region with different electrical characteristics. This parameter change enables threshold voltage adjustment and short channel effect mitigation while maintaining the small gate pitch geometry for high-density integration
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 approach enables a simpler manufacturing process, higher integration level, lower costs, and improved device performance by adjusting threshold voltage effectively and reducing short channel effects.
Implementation Method 1
the threshold voltage is adjusted by capacitive coupling between the backgate region and the source region or drain region
Implementation Method 2
a backgate region which is formed from the additional SOI layer by doping a portion of the additional SOI layer
Data Source
AI summary
The present application discloses a semiconductor structure and a method for manufacturing the same. A semiconductor structure according to the present invention can adjust the threshold voltage by capacitive coupling between a backgate region either and a source region or a drain region with a common contact, i.e. a source contact or a drain contact, which leads to a simple manufacturing process, a higher integration level, and a lower manufacture cost. Moreover, the asymmetric design of the backgate structure, together with the doping of the backgate region which can be varied as required in an actual device design, can further enhance the effects of adjusting the threshold voltage and improve the performances of the device.