Trench Isolation Structure for Semiconductor Electric Breakdown Prevention
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Solution Overview
Problem
Existing semiconductor technologies face challenges in achieving effective electric isolation between neighboring circuit elements, such as bipolar junction transistors and field effect transistors, to prevent electric breakdown within specified operational voltage ranges, particularly in high-power applications like automotive and industrial systems.
Innovation Solution
A semiconductor device structure is developed with a trench isolation and substrate contact structure, featuring a semiconductor substrate of a first conductivity type, a first semiconductor layer of a second conductivity type, a buried semiconductor layer of the second conductivity type, and a conductive filling in the trench, which is electrically coupled to the substrate, using insulating materials to line the trench and enhance electric isolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional isolation techniques are used, then manufacturing simplicity is maintained, but electric isolation between neighboring circuit elements is insufficient
Solution Approach 1:
The semiconductor device is divided into isolated regions by trenches that extend through multiple layers (second semiconductor layer, buried semiconductor layer, and first semiconductor layer) into the substrate. This segmentation physically separates neighboring circuit elements, preventing electrical breakdown and enabling independent operation within specified voltage ranges.
Solution Approach 2:
An insulating structure is introduced as an intermediary material filling the trench between neighboring circuit elements. This insulating layer acts as a mediator that blocks electrical breakdown paths while allowing each circuit element to operate independently, thereby improving electric isolation without requiring fundamental changes to the device architecture.
2Reliability
If isolation structures are added to prevent breakdown, then electric isolation is improved, but device complexity increases
Solution Approach 1:
Instead of adding lateral isolation structures that would increase planar complexity, the invention extends isolation into the vertical dimension by creating trenches that penetrate through multiple layers. This vertical approach provides effective breakdown prevention while maintaining relative simplicity in the lateral device layout and circuit design.
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 configuration effectively suppresses parasitic substrate transistors, promotes electric contact, and adjusts the breakdown voltage, enabling reliable operation of semiconductor devices in high-voltage applications by improving electric isolation and voltage blocking capabilities.
Implementation Method 1
An insulating structure lines walls of the trench
Implementation Method 2
A conductive filling is in the trench and electrically coupled to the semiconductor substrate at a bottom of the trench
Implementation Method 3
This configuration effectively suppresses parasitic substrate transistors
Data Source
AI summary
A semiconductor device includes a semiconductor substrate of a first conductivity type. A first semiconductor layer of a second conductivity type is on the semiconductor substrate. A buried semiconductor layer of the second conductivity type is on the first semiconductor layer. A second semiconductor layer of the second conductivity type is on the buried semiconductor layer. A trench extends through each of the second semiconductor layer, the buried semiconductor layer, and the first semiconductor layer, and into the semiconductor substrate. An insulating structure lines walls of the trench. A conductive filling in the trench is electrically coupled to the semiconductor substrate at a bottom of the trench.