Deep Trench Isolation Structure for Semiconductor Injection Suppression
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Solution Overview
Problem
Charge carriers in semiconductor dies of integrated circuits can flow in unintended paths, leading to malfunctions such as latch-up and overheating, particularly in high-power devices adjacent to other components.
Innovation Solution
A deep trench isolation (DTI) structure is introduced between device regions, featuring a doped semiconductor fill that captures charge carriers at the bottom of the trench to prevent unwanted current pathways, using complementary doping to enhance isolation and reduce current injection by more than one order of magnitude.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If deep trench isolation structure is introduced to prevent charge carrier flow in unintended paths, then reliability is improved, but device complexity increases
Solution Approach 1:
The semiconductor substrate is divided into separate device regions by deep trenches filled with isolation material. This segmentation physically divides the substrate into isolated regions, preventing charge carrier flow between adjacent devices and eliminating latch-up conditions while maintaining individual device functionality.
Solution Approach 2:
A deep trench filled with isolation material (such as silicon dioxide or polysilicon) is introduced as an intermediary structure between adjacent doped regions. This intermediary physically blocks and electrically isolates charge carrier paths, preventing unwanted current flow and injection between neighboring devices.
2Object-generated harmful factors
If complementary doping is used in the deep trench isolation structure to enhance isolation, then current injection is reduced, but manufacturing precision requirements increase
Solution Approach 1:
Complementary doping is applied locally at the bottom of the deep trench isolation structure, specifically in the substrate region beneath the trench. This localized doping creates a junction that repels charge carriers of the opposite polarity, enhancing isolation effectiveness at the critical interface without requiring precise doping throughout the entire structure.
Solution Approach 2:
The doping concentration and type are changed in the substrate region beneath the deep trench to create a complementary doped region. This parameter change (from original substrate doping to complementary doping) creates an electric field that actively repels charge carriers, reducing current injection by more than one order of magnitude.
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 DTI structure effectively prevents charge carrier flow in unintended paths, significantly reducing the likelihood of latch-up and ensuring reliable operation of integrated circuits by curtailing excessive current flows.
Implementation Method 1
filling the trench with a complementary-type doped semiconductor fill to generate a deep trench isolation (DTI) structure
Data Source
AI summary
Some embodiments relate to an integrated circuit (IC) structure having a low-resistivity P-type semiconductor substrate, an epitaxial layer that is substantially P-type doped on the semiconductor substrate, a first device region including a first transistor device in a first well of P-type doped semiconductor material in the epitaxial layer, a second device region in the epitaxial layer, and a deep trench isolation (DTI) structure interposed between the first device region and the second device region. The DTI structure extends through the epitaxial layer and includes a sidewall comprising a dielectric material and a N-type doped semiconductor fill conductively connected to the substrate.