High-Voltage Isolation Stack to Prevent Lateral Charge Leakage
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Solution Overview
Problem
High voltage microelectronic devices face lateral charge leakage and isolation failures due to the thin first bandgap dielectric layer between high and low voltage nodes, despite vertical breakdown protection provided by multiple dielectric layers.
Innovation Solution
A method involving the formation of a plurality of dielectric layers with varying thicknesses and bandgaps, where the third layer is partially removed to expose the second layer laterally, and a metal layer is etched to fully expose the second dielectric layer, creating non-parallel sidewalls for enhanced lateral protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thin first bandgap dielectric layer is used between high and low voltage nodes, then vertical breakdown protection is provided by multiple dielectric layers, but lateral charge leakage occurs in the thin first bandgap dielectric layer
Solution Approach 1:
The first bandgap dielectric layer is segmented into two portions: a first portion extending between the high voltage node and low voltage node, and a second portion laterally positioned relative to the high voltage node. This segmentation allows different regions of the same dielectric layer to serve different functions - vertical isolation and lateral charge containment respectively.
Solution Approach 2:
The solution extends the functionality of the first bandgap dielectric layer into the lateral dimension by adding a second portion that is laterally positioned relative to the high voltage node. This dimensional extension provides lateral charge leakage protection without compromising the vertical breakdown protection provided by the first portion.
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 reduces or eliminates lateral charge leakage and enhances breakdown protection between high and low voltage nodes, improving the reliability of high voltage microelectronic devices.
Implementation Method 1
a first bandgap dielectric layer, such as silicon nitride (SiN), proximate the high voltage node, followed by a second and relatively thicker higher-bandgap dielectric, followed by a third layer (or a stack of layers forming the third layer) of an even thicker and highest-bandgap dielectric, between the thicker higher-bandgap dielectric and the low voltage node. The bandgap (electron mobility) of each layer differs, so that each layer provides some level of breakdown protection
Implementation Method 2
during the forming a second voltage node step a portion of the third layer in a region outwardly positioned relative to the second voltage node is removed to expose the second layer in the region
Data Source
AI summary
A method forms a first voltage node of a high voltage component of a microelectronic device. The method also forms a plurality of dielectric layers. The method also forms a second voltage node of the high voltage component of the microelectronic device in a fourth position such that the plurality of dielectric layers is between the first voltage node and the second voltage node. During the forming a second voltage node step, a portion of a third layer in the plurality of dielectric layers, in a region outwardly positioned relative to the second voltage node, is removed to expose the second layer, in the plurality of dielectric layers, in the region.