Semiconductor Pad Structure Using Tungsten Via to Prevent Peeling
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Solution Overview
Problem
The existing semiconductor devices with barrier metals containing titanium face issues with low adhesion to interlayer dielectric films, leading to peeling problems when stress is applied, particularly in the active portion and pad regions, which can result in decreased device performance and reliability.
Innovation Solution
The introduction of a tungsten portion within through holes in the interlayer dielectric film, which reduces the area of the interface between the barrier metal layer and the interlayer dielectric film, enhancing adhesion and preventing peeling by providing better contact and structural support.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a barrier metal containing titanium is provided, then electrical connection is improved, but adhesion to interlayer dielectric film deteriorates causing peeling
Solution Approach 1:
The patent introduces a tungsten portion as an intermediary element between the barrier metal layer and the interlayer dielectric film. This tungsten portion fills through-holes and provides a transition zone that improves adhesion. The tungsten acts as a mediator that bridges the interface between materials with poor direct adhesion, preventing peeling while maintaining the electrical connection function of the barrier metal.
Solution Approach 2:
The patent creates a composite structure by combining barrier metal (titanium-containing), tungsten, and interlayer dielectric film in a multi-layer configuration. This composite approach leverages the electrical properties of the barrier metal while using tungsten to provide mechanical adhesion support, thus resolving the contradiction between electrical performance and adhesion strength.
2Reliability
If barrier metal layer area is increased to improve coverage, then electrical connection is enhanced, but peeling resistance deteriorates due to larger interface area
Solution Approach 1:
The patent segments the barrier metal layer into two functional parts: a wide upper portion that provides excellent electrical connection and coverage, and a narrowed lower portion (through-hole region) filled with tungsten that provides adhesion stability. This segmentation allows each part to optimize its function without compromising the other, resolving the contradiction between coverage area and interface stability.
Solution Approach 2:
The patent applies local quality by having different regions of the barrier metal layer with different properties. The upper region has large area for electrical connection, while the lower region in the through-hole has reduced area and is supplemented with tungsten for adhesion. This local differentiation allows the structure to simultaneously achieve good electrical connection and peeling resistance.
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.