Semiconductor Pad Connection Structure for Barrier Layer Peeling
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Solution Overview
Problem
The existing semiconductor devices with barrier metals containing titanium face challenges with low adhesion to interlayer dielectric films, leading to peeling issues when stress is applied, particularly in the connection regions.
Innovation Solution
The introduction of a tungsten portion within a through hole in the interlayer dielectric film, combined with a barrier metal layer, reduces the area of the interface with weak adhesion, thereby enhancing the adhesion between the barrier metal layer and the interlayer dielectric film, and preventing peeling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a barrier metal containing titanium is provided, then electrical conductivity is improved, but adhesion to interlayer dielectric film deteriorates
Solution Approach 1:
A tungsten plug is introduced as an intermediary element between the barrier metal layer and the interlayer dielectric film. The tungsten plug has a smaller area than the barrier metal layer, creating a stepped structure that reduces the interface area where peeling occurs. This intermediary structure allows the barrier metal to maintain its electrical conductivity function while the tungsten plug provides a more stable mechanical anchor point, thereby resolving the adhesion problem without sacrificing electrical performance.
2Reliability
If barrier metal layer area is increased, then electrical conductivity is improved, but peeling resistance deteriorates
Solution Approach 1:
The conductive path is segmented into two distinct parts: a larger barrier metal layer that provides electrical conductivity and a smaller tungsten plug that provides mechanical strength. This segmentation allows each material to optimize its specific function - the barrier metal maintains low resistance over a larger area, while the tungsten plug concentrates the mechanical load over a smaller, stronger area, thereby resolving the contradiction between conductivity and peeling resistance.
Solution Approach 2:
Different regions of the structure are assigned different qualities and functions. The barrier metal layer is designed with larger area for electrical conductivity, while the tungsten plug is designed with smaller area for mechanical anchoring. This local differentiation of quality allows the structure to simultaneously achieve both electrical performance and mechanical stability without requiring the entire structure to compromise either property.
Data Source
AI summary
There is provided a semiconductor device including: a pad portion that is provided above the upper surface of the semiconductor substrate and that is separated from the emitter electrode; a wire wiring portion that is connected to a connection region on an upper surface of the pad portion; a wiring layer that is provided between the semiconductor substrate and the pad portion and that includes a region overlapping the connection region; an interlayer dielectric film that is provided between the wiring layer and the pad portion and that has a through hole below the connection region; a tungsten portion that contains tungsten and that is provided inside the through hole and electrically connects the wiring layer and the pad portion; and a barrier metal layer that contains titanium and that is provided to cover an upper surface of the interlayer dielectric film below the connection region.