Semiconductor Oxide Layout for Gate Breakdown and Kirk Effect
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Solution Overview
Problem
Double diffusion drain metal oxide semiconductor (DDDMOS) devices in high voltage circuits face issues with electric field damage near the gate structure due to high voltage, leading to potential device failure.
Innovation Solution
A semiconductor structure is designed with thick oxide layers on the left and right sides of the gate structure and a thin oxide layer in the center, protected by shallow trench isolation structures, to mitigate electric field stress and prevent breakdown while avoiding the Kirk effect.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a uniform thick oxide layer is formed under the gate structure to protect from electric field damage, then gate structure protection is improved, but Kirk effect occurs
Solution Approach 1:
The patent applies local quality by creating non-uniform oxide layer thickness across different regions. Specifically, the oxide layer thickness varies from the first region through the second region to the third region, with each region having different thickness characteristics. This local variation allows the structure to simultaneously achieve gate protection where needed while avoiding Kirk effect in the central region, resolving the contradiction between protection and performance.
2Productivity
If high voltage is introduced to provide large output current, then productivity is improved, but electric field damage to gate structure occurs
Solution Approach 1:
The patent implements beforehand cushioning by forming an oxide layer prior to introducing high voltage operation. This oxide layer acts as a protective cushion that mitigates the harmful electric field effects before they can damage the gate structure. The oxide layer is formed in advance during the manufacturing process, providing pre-protection that enables high voltage operation without gate damage.
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 structure effectively protects the gate structure from high current-induced breakdown and prevents the Kirk effect, maintaining device performance and reliability.
Implementation Method 1
it will produce a strong electric field, especially near the edge of the gate structure, which may cause the electric field to pass through the gate structure and cause damage to the device
Implementation Method 2
the thin oxide layers remain in the central part, which can also avoid the influence of Kirk effect
Data Source
AI summary
The invention provides a semiconductor structure, the semiconductor structure includes a substrate, two shallow trench isolation structures are located in the substrate, a first region, a second region and a third region are defined between the two shallow trench isolation structures, the second region is located between the first region and the third region. Two thick oxide layers are respectively located in the first region and the third region and directly contact the two shallow trench isolation structures respectively, and a thin oxide layer is located in the second region, the thickness of the thick oxide layer in the first region is greater than that of the thin oxide layer in the second region.