Hall Device Impurity Optimization for Linear Temperature Correction
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Solution Overview
Problem
Conventional Hall devices require extensive testing to achieve accurate quadratic correction functions for temperature characteristics, leading to increased time and cost, and often compromise on magnetic detection accuracy due to the need for multiple sensitivity measurements.
Innovation Solution
A Hall device with a p-type impurity region and an n-type impurity region, where the n-type impurity concentration and distribution depth are optimized to satisfy specific relational expressions, allowing for accurate temperature correction using measurements at only two or three temperatures, thereby reducing the number of necessary sensitivity measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional Hall devices use standard n-type impurity concentration ranges, then the device structure is simple and manufacturing is easier, but the temperature characteristics show secondary temperature characteristics requiring quadratic correction functions and extensive testing
Solution Approach 1:
The patent changes the n-type impurity concentration parameter from conventional ranges (5x10^17 to 5x10^19 atoms/cm³) to a specific low concentration range (1x10^16 to 1x10^18 atoms/cm³). This parameter change transforms the temperature characteristics from secondary (requiring quadratic correction) to substantially linear (requiring only linear correction), thereby improving measurement precision while maintaining manufacturing simplicity
Solution Approach 2:
The patent performs preliminary action by pre-determining the optimal n-type impurity concentration range during device design and manufacturing. This preliminary optimization of the impurity concentration ensures that the Hall device inherently exhibits linear temperature characteristics, eliminating the need for complex post-manufacturing testing and correction procedures
2Measurement precision
If extensive temperature testing is performed to achieve accurate quadratic correction functions, then magnetic field detection accuracy is improved, but the testing time and cost increase significantly
Solution Approach 1:
By changing the n-type impurity concentration to the specified low range, the patent fundamentally alters the temperature characteristic behavior from secondary to linear. This parameter change enables accurate magnetic field detection with simplified linear correction based on only two temperature points, dramatically reducing testing time and cost compared to conventional quadratic correction requiring five-point temperature testing
3Measurement precision
If five-point temperature testing is conducted to achieve accurate correction functions, then correction accuracy is improved, but the number of test steps and costs increase
Solution Approach 1:
The patent changes the impurity concentration parameter to achieve linear temperature characteristics, which reduces the correction process from requiring five temperature points (quadratic correction) to only two temperature points (linear correction). This parameter change maintains correction accuracy while significantly simplifying the test process and reducing costs
Solution Approach 2:
The patent applies partial action by using only two temperature points for correction instead of the conventional five-point testing. This partial testing approach is sufficient because the linear temperature characteristics (achieved through optimized impurity concentration) allow accurate correction with fewer data points, reducing test process complexity while maintaining correction accuracy
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 high-accuracy magnetic field detection with a correction residual error of 1.0% or less between -40°C and 150°C, while minimizing the number of test steps and costs involved in calibrating the Hall device.
Implementation Method 1
a vertical Hall device that can enhance a degree of freedom in selecting a substrate used to form a Hall device and a manufacturing method thereof. The vertical Hall device is formed on a semiconductor substrate formed of P-type silicon and outputs a Hall voltage signal corresponding to a magnetic field component when the magnetic field component parallel to the surface of the semiconductor substrate is applied to a magnetic detection portion HP in a state where a current including a component perpendicular to the surface of the semiconductor substrate is supplied to the magnetic detection portion HP in an N-type semiconductor region 12.
Data Source
Figure 1
Figure 2A~2B
Figure 3~4
AI summary
By restricting the concentration and the depth of an n-type impurity region which is a magnetosensitive portion of a Hall device to appropriate ranges, it is possible to improve linearity of temperature characteristics in detecting a magnetic field intensity with high accuracy. In order to obtain linearity of the temperature characteristics of the constant-current sensitivity, there is provided a Hall device including a p-type impurity region 1 and an n-type impurity region 2 that is disposed on the p-type impurity region 1 and that serves as a magnetosensitive portion, wherein an n-type impurity concentration N and a distribution depth D of the n-type impurity region 2 satisfy relational expressions of N<1.0x1016 and N>3.802x1016xD-1.761.