Nested Electrode Trench Structure for Semiconductor Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor devices with a stripe trench configuration, existing technologies face challenges in effectively contacting and isolating multiple electrodes within a trench, particularly in achieving a planar surface for subsequent insulation and electrode formation, which affects the device's performance and reliability.
Innovation Solution
A method involving the formation of a trench with a stripe configuration, where a first electrode is partially etched to create a planar surface, followed by insulation and the deposition of a second electrode within the trench, ensuring the electrodes are insulated from each other and extending towards the surface for common lateral and vertical extension ranges, allowing for selective etching and improved contact structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple electrodes are placed within a stripe trench for dual-poly-trench configuration, then the device functionality and control capability are improved, but the complexity of electrode isolation and contact structures increases
Solution Approach 1:
The patent implements a nested electrode structure where a first electrode extends deeper into the trench than a second electrode, creating a well that incorporates the second electrode. This nesting approach allows multiple electrodes to be accommodated within the same trench space while maintaining clear isolation through the insulator layer, thereby improving device functionality without proportionally increasing structural complexity
Solution Approach 2:
The patent divides the trench into distinct segments using insulator layers that laterally confine the electrodes. The first insulator insulates the first electrode from the semiconductor body, while the second insulator insulates the second electrode from the first electrode. This segmentation enables independent control of each electrode while simplifying the overall isolation structure
2Ease of manufacture
If a planar surface is created by partial etching of the first electrode, then subsequent insulation and electrode formation is simplified, but the manufacturing process steps increase
Solution Approach 1:
The patent performs a partial etching step on the first electrode before depositing the insulator and forming the second electrode. This preliminary action creates a planar surface that facilitates subsequent processing steps, making the insulation and electrode formation easier to execute with better process control and uniformity
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 enhances the semiconductor device's performance by enabling effective insulation and contact between electrodes, improving the device's conductivity and reliability, particularly in high-voltage and high-current applications.
Implementation Method 1
carrying out a first etching step for partially removing the first electrode along the total lateral extension of the first electrode such that the remaining part of the first electrode has a planar surface
Implementation Method 2
depositing a second insulator on top the planar surface
Implementation Method 3
forming a groove within the trench by etching, at the first lateral termination area, a lateral extremity of the second electrode, wherein said etching is selective to the second insulator
Data Source
AI summary
A semiconductor device includes a semiconductor body having a main surface and an active region surrounded by a non-active region. A trench extends from the main surface into the semiconductor body. The trench has a stripe configuration and extends laterally within the active region. A first electrode and a first insulator are in the trench. The first insulator insulates the first electrode from the semiconductor body. The first electrode is recessed in the trench and has a planar surface extending generally parallel with and below the main surface of the semiconductor body so as to define a well in the trench that is laterally confined by the first insulator. A second insulator is on the planar surface. A second electrode is within the well of the trench, and the second insulator insulates the second electrode from the first electrode.