Polysilicon Resistor Contact Structure for Low Temperature Coefficient
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor resistance devices struggle to miniaturize while maintaining a small temperature coefficient, as they require combining two types of resistors with different temperature coefficients, making it difficult to reduce the size of the resistor element.
Innovation Solution
A semiconductor device is designed with a polysilicon layer, a resistance region, and contact regions with varying impurity concentrations to create low and high resistance contact structures, allowing for a small temperature coefficient and miniaturization of the resistance element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two types of resistors with different temperature coefficients are combined to achieve a small temperature coefficient, then the temperature coefficient is reduced, but the size of the resistor element increases
Solution Approach 1:
The patent applies local quality by creating contact regions with different impurity concentrations (first contact region with higher impurity concentration than the resistance region) at specific locations within the resistor structure. This allows different portions of the same resistor to have different electrical characteristics, enabling temperature coefficient compensation without requiring separate resistor elements.
Solution Approach 2:
The patent changes the impurity concentration parameter within the polysilicon layer to create regions with different resistance characteristics. By forming contact regions with higher impurity concentrations than the surrounding resistance region, the patent modifies the local electrical parameters to achieve the desired temperature coefficient while maintaining a compact single-element structure.
2Reliability
If contact regions with high impurity concentration are formed to reduce contact resistance, then contact resistance decreases, but the temperature coefficient control becomes more difficult
Solution Approach 1:
The patent creates distinct contact regions with higher impurity concentrations than the resistance region, allowing these contact portions to have low contact resistance while the main resistance region maintains its temperature coefficient characteristics. This spatial differentiation of material properties resolves the conflict between low contact resistance and temperature coefficient control.
Solution Approach 2:
The patent segments the polysilicon layer into functionally distinct regions: resistance regions with specific impurity concentrations for temperature coefficient control, and contact regions with higher impurity concentrations for low contact resistance. This segmentation allows each region to independently optimize its function without interfering with the other.
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 device achieves miniaturization of resistance elements with small or near-zero temperature coefficients by optimizing the contact resistance structures and impurity concentrations, enhancing the device's compactness and performance.
Implementation Method 1
a first contact region provided in the resistance region, the first contact region having the same conductivity type as the resistance region and having a higher impurity concentration than the resistance region
Implementation Method 2
at least one of the plurality of first vias and the plurality of second vias is in contact with the first contact region so as to form a low resistance contact structure with respect to the resistance region
Implementation Method 3
a resistance region provided in the polysilicon layer... by appropriately selecting the number of sheets of the p-type polysilicon resistor with a positive temperature coefficient and the number of sheets of the n-type polysilicon resistor with a negative temperature coefficient, the characteristic change due to temperature is offset
Data Source
AI summary
A semiconductor resistance device includes a polysilicon resistance region; a first contact region in the resistance region, the first contact region having the same conductivity type as the resistance region and having a higher impurity concentration than the resistance region; a first wiring electrically connected to one end of the resistance region via a plurality of first vias; and a second wiring electrically connected to the other end of the resistance region via a plurality of second vias. At least one of the plurality of first vias and the plurality of second vias is in contact with the first contact region so as to form a low resistance contact structure, and at least another one of the plurality of first vias and the plurality of second vias forms a high resistance contact structure that has a contact resistance higher than a contact resistance of the low resistance contact structure.