Self-Aligned Barrier Gate Structures for Quantum Dot Alignment
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Solution Overview
Problem
The limited coherence time of spin qubits in semiconductor devices restricts their potential applications in quantum computers.
Innovation Solution
The implementation of self-aligned barrier gates interdigitated with spin qubit gates, using polysilicon or metal fill, which reduces variation and improves alignment, and is compatible with current CMOS flows.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If self-aligned barrier gates are implemented, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The patent combines the barrier gate and spin qubit gate fabrication into a single self-aligned process step. The barrier gates are formed using the same lithographic pattern as the spin qubit gates, eliminating the need for separate alignment steps and reducing manufacturing complexity while maintaining high precision alignment between gate structures.
Solution Approach 2:
The gate dielectric layer is deposited and patterned beforehand to create self-aligned regions that automatically define the barrier gate positions. This preliminary structuring ensures that subsequent metal or polysilicon fill for the barrier gates occurs precisely where needed, achieving high alignment accuracy without additional alignment steps.
2Area of moving object
If gate area is minimized, then qubit density is improved, but manufacturing precision requirements increase
Solution Approach 1:
By using self-aligned fabrication where barrier gates and spin qubit gates are patterned simultaneously in the same lithographic step, the patent achieves minimal gate spacing and area while ensuring precise alignment. The shared patterning process inherently maintains the required precision even as dimensions are reduced for higher density.
3Adaptability or versatility
If spin qubits are implemented in semiconductor devices, then device functionality is improved, but coherence time is reduced
Solution Approach 1:
The patent implements localized barrier gates that create precisely defined quantum dot regions with controlled potential profiles. By optimizing the local electric field distribution through the barrier gate positioning and geometry, the quantum confinement is enhanced, improving qubit coherence time while maintaining the functionality of spin qubit implementation in standard semiconductor materials.
Data Source
AI summary
The present disclosure relates to semiconductor structures and, more particularly, to quantum dot structures and methods of manufacture. The structure includes: a plurality of barrier gates; a plurality of spin qubit gates interdigitated with the plurality of barrier gates; and access gates on opposing sides of the plurality of barrier gates.