Vertical Hall Sensor Minority Carrier Injection
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Solution Overview
Problem
Conventional Hall sensors experience temporary depletion of minority carriers at low operating currents, leading to unstable startup behavior and drift in measured values, particularly due to the lack of minority carriers and threshold voltage implantation issues.
Innovation Solution
A vertical Hall sensor structure is designed with semiconductor contact areas of different conductivity types, where a second conductivity type contact area is strategically placed adjacent to or close to the first conductivity type contact areas, forming an electrically conductive connection to provide minority carriers and improve startup behavior, thereby stabilizing measurements immediately after activation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional Hall sensor structure is used with spaced contact areas, then manufacturing is simplified, but minority carriers are depleted at low currents causing unstable startup behavior
Solution Approach 1:
The contact area is segmented into multiple conductivity types (first and second conductivity types) with different functions. The first conductivity type contact areas are spaced for standard current flow, while the second conductivity type contact areas are positioned adjacent to provide minority carriers, dividing the contact structure into functional segments that solve the startup stability issue without complicating the overall device manufacturing
Solution Approach 2:
The second conductivity type contact areas act as intermediary elements that provide minority carriers to the semiconductor area. These intermediary contact areas are positioned between the first conductivity type contact areas and the semiconductor area, mediating the carrier supply to prevent depletion and ensure stable startup behavior at low currents
2Measurement precision
If threshold voltage implantation is applied to low doped semiconductor areas, then sensitivity is improved, but startup behavior deteriorates due to minority carrier depletion
Solution Approach 1:
Different contact areas are assigned different conductivity types and positions to perform different functions. The first conductivity type contact areas maintain spacing for sensitivity, while the second conductivity type contact areas are locally positioned adjacent to the semiconductor area to provide minority carriers for stable startup, creating local quality variations that resolve the contradiction between sensitivity and startup stability
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 design enhances the transient characteristics and sensitivity of the Hall sensor by ensuring stable and reliable measurements from startup, suppressing drift and avoiding threshold voltage implantation, even at low doped semiconductor areas.
Implementation Method 1
The first semiconductor contact area of the first conductivity type is connected to the first semiconductor contact area of the second conductivity type in an electrically conductive manner
Implementation Method 2
The semiconductor area is electrically insulated from the substrate layer by means of a dielectric layer
Implementation Method 3
The semiconductor area is electrically insulated from the substrate layer by means of a p/n junction
Implementation Method 4
a vertical Hall sensor structure is provided, comprising a substrate layer with a semiconductor area formed on or in the substrate layer
Data Source
AI summary
A vertical Hall sensor structure having a substrate layer, a semiconductor area of a first conductivity type, at least a first, a second and a third semiconductor contact area of the first conductivity type extending from an upper surface of the semiconductor area into the semiconductor area, and at least a first semiconductor contact area of a second conductivity type, wherein the semiconductor contact areas of the first conductivity type are spaced apart from each other and a metal connection contact layer is arranged on each semiconductor contact area of the first conductivity type. The first semiconductor contact area of the second conductivity type is adjacent to the first semiconductor contact area of the first conductivity type or is spaced at a distance of at most 0.2 μm from the first semiconductor contact area of the first conductivity type.