Bridging Metal Layer in Supporting Post Vias for Stable Connections
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Solution Overview
Problem
Existing semiconductor processes face challenges in achieving precise control of supporting post via holes in microbolometers, leading to poor metal connections and circuit breaks due to anisotropic etching, which affects process yield and imaging quality.
Innovation Solution
A method involving a bridging metal layer is introduced within the supporting post via holes, using controlled deposition and photomask design to ensure stable metal connections, comprising layers of silicon nitride, titanium, and vanadium, to enhance yield and quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If dry etching process is used to form supporting post via holes, then via holes can be formed with steep edges, but the holes become tapered with poor metal connection control
Solution Approach 1:
The patent applies preliminary action by depositing a bridging metal layer at the bottom of the via holes before forming the main connecting metal layer. This preliminary bridging layer compensates for the tapered shape and steep edges created by dry etching, ensuring reliable metal connections without requiring perfect via hole geometry control.
2Reliability
If supporting post height exceeds 2.5 μm for optimal infrared absorption, then infrared detection performance improves, but via hole depth increases causing poor metal deposition control
Solution Approach 1:
The patent applies local quality by creating a bridging metal layer with specific local properties at the bottom of deep via holes. This localized metal layer provides enhanced adhesion and connection reliability in the critical deep via region, while allowing the rest of the via to maintain the tapered shape necessary for supporting the tall posts required for infrared absorption.
3Reliability
If precise control of cut angle is implemented to prevent steep edge effects, then metal connection quality improves, but process complexity and time increase
Solution Approach 1:
The patent introduces a bridging metal layer as an intermediary between the via hole structure and the main connecting metal layer. This intermediary layer mediates the connection, allowing the use of standard dry etching processes without precise angle control while still achieving reliable metal connections through the compensating bridging structure.
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 method improves process yield and reduces circuit breaks, ensuring stable signal conduction and high-quality integrated circuits by preventing steep edge effects and maintaining thermal insulation.
Implementation Method 1
forming a bridging metal layer in the supporting post via holes
Implementation Method 2
forming a sacrificial layer on the first coating layer, and then forming a dielectric supporting layer on the sacrificial layer
Data Source
AI summary
A method for attaching a bridging metal layer in supporting post via holes in an integrated circuit device is provided. The method include: (A) providing an integrated circuit wafer with a first coating layer as the outermost layer; (B) forming a sacrificial layer on the first coating layer and then forming a dielectric supporting layer on the sacrificial layer to obtain multiple supporting post via holes; (C) forming a bridging metal layer in the supporting post via holes and then forming a second coating layer; and (D) forming a connecting metal layer on the bridging metal layer and then forming a third coating layer on the bridging metal layer to obtain multiple supporting posts.