Capacitive Coupling Across Deep Trench Isolation for High-Voltage ICs
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing integrated circuits for power electronics face challenges in efficiently and economically scaling with different voltage isolation requirements, particularly in multi-voltage domain processing, where full galvanic isolation is needed while allowing information and power exchange between voltage domains.
Innovation Solution
A multi-voltage domain device is designed with a semiconductor layer having regions for different voltage domains and deep trench isolation barriers that extend vertically to laterally isolate these regions. Capacitors with electrodes on the sidewalls of the isolation region enable lateral electric field generation for signal transmission across the isolation regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If planar electrodes with vertical electric fields are used in the BEOL layer stack to achieve high voltage isolation, then the insulation voltage rating is improved, but the manufacturing complexity and cost increase due to additional metal and dielectric layers
Solution Approach 1:
The patent transitions from vertical electric fields (planar electrodes stacked vertically in the BEOL) to lateral electric fields (electrodes positioned side-by-side in the same or fewer BEOL layers). This dimensional change allows achieving the same isolation effect without adding vertical layers, thereby reducing manufacturing complexity while maintaining voltage isolation reliability.
2Reliability
If additional metal and dielectric layers are added vertically to the BEOL layer stack to achieve higher voltage ratings, then the voltage isolation capability is improved, but the manufacturing cost and process complexity worsen
Solution Approach 1:
Instead of increasing vertical layer count to improve voltage isolation, the patent positions electrodes laterally adjacent to each other within the same or fewer BEOL layers. The lateral arrangement achieves the required isolation using existing layer structures, avoiding additional manufacturing steps and reducing cost.
3Reliability
If planar electrodes are used with adjusted dielectric thickness to accommodate different voltage domain requirements, then the voltage domain isolation is improved, but the device area and manufacturing flexibility worsen
Solution Approach 1:
The patent arranges electrodes laterally side-by-side rather than stacking them vertically. This lateral configuration achieves the required dielectric thickness for voltage isolation without increasing the vertical layer count, thereby reducing the overall device footprint while maintaining proper isolation between voltage domains.
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 solution allows for efficient and cost-effective signal transmission and power exchange between different voltage domains, eliminating the need for thick dielectric layers in the BEOL process and enabling scalable manufacturing for various isolation requirements.
Implementation Method 1
Capacitive couplers placed between the different voltage domains may be used to transmit information
Implementation Method 2
at least one first capacitor configured to generate an electric field laterally across the isolation region between the first region and the second region
Data Source
AI summary
A multi-voltage domain device includes a semiconductor layer including a first main surface, a second main surface arranged opposite to the first main surface, a first region including first circuitry that operates in a first voltage domain, a second region including second circuitry that operates in a second voltage domain different than the first voltage domain, and an isolation region that electrically isolates the first region from the second region in a lateral direction that extends parallel to the first and the second main surfaces. The isolation region includes at least one deep trench isolation barrier, each of which extends vertically from the first main surface to the second main surface. The multi-voltage domain device further includes at least one first capacitor configured to generate an electric field laterally across the isolation region between the first region and the second region.