Integrated Planar and Vertical Hall Element for 3D Sensing
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Solution Overview
Problem
Existing 3D Hall effect sensors face challenges in design flexibility, footprint efficiency, and cross-interference due to the integration of 1D and 2D elements, which affects sensing accuracy and cost-effectiveness.
Innovation Solution
A 3D Hall element design that integrates planar and vertical elements operating at different phases of a clock cycle, with separate sensing for each magnetic field component, utilizing shallow trench isolation (STI) and deep trench isolation (DTI) regions to reduce cross-interference and optimize sensitivity without additional masks or space requirements, compatible with CMOS technology nodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If 3-Axis Hall sensors are integrated using six building blocks, then 3D sensing capability is achieved, but device complexity and assembly process complexity increase significantly
Solution Approach 1:
The patent combines planar Hall elements and vertical Hall elements into a single integrated 3D Hall sensor device. Instead of assembling six separate building blocks, the invention integrates multiple sensing elements (first and second planar Hall elements, first and second vertical Hall elements) into one unified structure, thereby achieving 3D sensing capability while significantly reducing assembly process complexity
Solution Approach 2:
The integrated Hall sensor device performs multiple functions within a single structure: it senses magnetic fields in three-dimensional space (Bx, By, Bz components) using both planar and vertical elements, eliminating the need for multiple separate sensors and simplifying the overall system architecture
2Measurement precision
If multiple contact Hall sensors are used for 3D sensing, then sensing coverage is improved, but cross-interference between magnetic field sensing increases
Solution Approach 1:
The patent segments the sensing function into distinct planar and vertical Hall elements, each dedicated to specific magnetic field components. The planar elements sense in-plane fields while vertical elements sense perpendicular fields, reducing cross-interference by separating sensing functions into independent segments that operate without mutual interference
Solution Approach 2:
The patent introduces a p-type well as an intermediary structure between the n-type wells containing the Hall elements. This p-type well acts as a mediator that provides electrical isolation and reduces cross-interference between adjacent Hall elements while maintaining their individual sensing capabilities
3Measurement precision
If doping or thickness of vertical Hall element is reduced to improve sensitivity, then sensitivity increases, but planar Hall element performance may be affected
Solution Approach 1:
The patent segments the doping and thickness optimization into separate regions: n-type wells for vertical Hall elements can have different doping concentrations and thicknesses optimized for vertical sensing sensitivity, while the planar Hall elements in separate regions maintain their own optimized parameters. This segmentation allows independent optimization of each element type without compromising the other
Solution Approach 2:
The patent applies local quality by allowing different regions of the device to have different doping concentrations and structural properties. The n-type wells containing vertical Hall elements can be doped and sized differently from regions containing planar Hall elements, enabling each local region to have the optimal properties for its specific sensing function
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
The solution achieves improved sensitivity and reduced cross-interference, enabling better design flexibility and cost-effectiveness by optimizing both planar and vertical Hall elements within a single footprint, enhancing magnetic field sensing accuracy and efficiency.
Implementation Method 1
A Hall effect is the production of a voltage difference (the Hall voltage) across an electrical conductor, transverse to an electric current in the conductor, and a magnetic field perpendicular to the current. When a current-carrying semiconductor is kept in a magnetic field, the charge carriers of the semiconductor experience a force in a direction perpendicular to both the magnetic field and the current.
Data Source
AI summary
A method of forming a 3D Hall effect sensor and the resulting device are provided. Embodiments include forming a shallow trench isolation (STI) region and a deep trench isolation (DTI) region in a substrate; forming a p-type well in the substrate surrounded by the STI region in top view; forming a first n-type well and a second n-type well surrounded by the p-type well and DTI region in top view; forming n-type dopant in the first n-type well and the second n-type well; and forming p-type dopant in the p-type well.