Semiconductor Column Buffer Layer for Lower Bottom Contact Resistance
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Solution Overview
Problem
In semiconductor devices, the contact resistance between semiconductor columns and bottom contacts is high due to direct connection through the substrate, leading to increased band offset differences at the interface, which hinders efficient current flow.
Innovation Solution
A buffer layer is formed over a portion of the substrate, with semiconductor columns connected to the buffer layer, reducing contact resistance by establishing a connection through the buffer layer, which has a lower band offset difference compared to direct substrate connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If semiconductor columns are directly connected to bottom contacts through the substrate, then the device structure is simple, but the contact resistance is high due to increased band offset differences at the interface
Solution Approach 1:
A buffer layer is introduced as an intermediary between the semiconductor columns and the substrate. This buffer layer has a band structure that reduces the band offset difference at the interface, thereby lowering contact resistance. The buffer layer acts as a mediator that facilitates better electrical contact without requiring direct connection between the semiconductor columns and the substrate.
Solution Approach 2:
The buffer layer changes the electrical parameters at the interface by providing a gradual transition in band energy levels. This parameter change reduces the abrupt band offset that causes high contact resistance, allowing for more efficient charge carrier transport between the semiconductor columns and the substrate.
2Reliability
If a buffer layer is introduced to reduce contact resistance, then current flow is improved, but the device structure becomes more complex
Solution Approach 1:
The buffer layer serves as a mediator that improves current flow by reducing the energy barrier at the interface. Despite adding a layer to the structure, the buffer layer's primary function is to facilitate charge carrier transport, thereby improving current flow efficiency while the added structural complexity is minimal.
3Productivity
If direct substrate connection is used, then the device structure is simple, but band offset differences increase and hinder efficient current flow
Solution Approach 1:
The buffer layer modifies the electrical parameters at the semiconductor-substrate interface by creating a gradual band structure transition. This parameter change reduces the band offset difference, enabling more efficient current flow. The buffer layer's composition and thickness are optimized to achieve the desired band alignment while minimizing structural complexity.
Data Source
AI summary
A semiconductor arrangement and methods of formation are provided. A semiconductor arrangement includes a semiconductor column on a buffer layer over a substrate. The buffer layer comprises a conductive material. Both a first end of the semiconductor column and a bottom contact are connected to a buffer layer such that the first end of the semiconductor column and the bottom contact are connected to one another through the buffer layer, which reduces a contact resistance between the semiconductor column and the bottom contact. A second end of the semiconductor column is connected to a top contact. In some embodiments, the first end of the semiconductor column corresponds to a source or drain of a transistor and the second end corresponds to the drain or source of the transistor.