Top-Side Contact Structure With Intersecting Trenches
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Solution Overview
Problem
Conventional semiconductor device fabrication methods require additional photomasks to define contact hole positions, increasing process complexity and manufacturing cost, and occupying valuable area for device miniaturization.
Innovation Solution
A top-side contact structure is formed by creating intersecting trenches with insulating material filling and a self-aligned contact plug at the intersection point, eliminating the need for additional photomasks and integrating with deep trench isolation structures to reduce complexity and cost while preserving device area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If additional photomasks are used to define contact hole positions, then contact precision is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines the contact hole definition function with the existing deep trench isolation structure. The trenches that form the isolation regions also serve to define and position the contact holes, eliminating the need for separate photomask steps. This merging of functions reduces process complexity while maintaining manufacturing precision.
Solution Approach 2:
The deep trench isolation structures are given multiple functions: they provide electrical isolation between devices and simultaneously serve as the positioning framework for contact holes. This multi-functionality eliminates the need for dedicated contact definition structures, reducing overall device complexity.
2Manufacturing precision
If additional photomasks are used to define contact hole positions, then contact hole positioning is improved, but manufacturing cost increases
Solution Approach 1:
The patent merges the contact hole positioning function into the existing deep trench isolation fabrication process. By using the same trench structures for both isolation and contact positioning, the number of required photomasks is reduced, directly lowering manufacturing costs while maintaining positioning accuracy.
3Reliability
If conventional contact structures are used, then contact formation is achieved, but valuable device area is occupied
Solution Approach 1:
The patent merges the contact structure with the deep trench isolation structure, so that the contact holes are formed at the intersections of the isolation trenches. This integration eliminates the need for separate contact definition areas, preserving valuable device area while ensuring reliable contact formation to the first semiconductor layer.
Data Source
AI summary
A top-side contact structure is provided. The top-side contact structure includes a substrate. The substrate includes a first semiconductor layer, an insulating layer on the first semiconductor layer, and a second semiconductor layer on the insulating layer. The top-side contact structure also includes a first trench and a second trench formed in the second semiconductor layer and respectively extending along a first direction and a second direction. The first trench and the second trench connect to each other at an intersection point. The top-side contact structure also includes an insulating material filling the first trench and the second trench. The top-side contact structure also includes a contact plug formed at the intersection point and directly contacting the first semiconductor layer. A method for fabricating a top-side contact structure is also provided.