Nitrogenous MIM Capacitor Structure for Copper Etching Contamination
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Solution Overview
Problem
Conventional MIM capacitors face issues with copper contamination during etching, leading to reduced dielectric breakdown voltage and potential device malfunction due to copper diffusion and pinhole/grain boundary formation.
Innovation Solution
The introduction of a nitrogenous dielectric layer and a multilayered blocking layer, treated with nitrogenous gas, effectively prevents copper diffusion by forming a thin nitrogenous film and multiple discrete interfaces, respectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional MIM capacitor structure is used, then manufacturing process is simple, but copper contamination occurs during etching leading to reduced dielectric breakdown voltage
Solution Approach 1:
The blocking layer is divided into multiple discrete layers (first blocking layer and second blocking layer) with different materials and functions. The first blocking layer (TaN) provides copper diffusion barrier, while the second blocking layer (TiN) provides additional protection and interface stability. This segmentation allows each layer to be optimized for specific functions, effectively preventing copper contamination without requiring complete redesign of the capacitor structure.
Solution Approach 2:
The blocking layers are formed on the dielectric layer before the metal electrode deposition process. This preliminary action creates a protective barrier that prevents copper contamination during subsequent etching and manufacturing steps. By establishing the defense mechanism before the harmful process occurs, the dielectric breakdown voltage is maintained without compromising manufacturing efficiency.
2Reliability
If blocking layer is added to prevent copper diffusion, then dielectric breakdown voltage is maintained, but manufacturing process complexity increases
Solution Approach 1:
The blocking layers are designed with specific thickness parameters (first blocking layer: 5-20 nm, second blocking layer: 5-15 nm) and specific material compositions (TaN and TiN). By optimizing these parameters, the layers provide effective copper diffusion protection while minimizing the additional process steps required. The thickness and material selection are tuned to achieve maximum protection with minimum process complexity.
3Reliability
If copper diffusion is prevented by multiple blocking layers, then device reliability is improved, but manufacturing time and process steps increase
Solution Approach 1:
The formation of the dual blocking layer structure is integrated with the existing capacitor manufacturing process flow. The blocking layers are deposited using standard PVD or CVD techniques that are already part of the fabrication line. By merging the copper protection function into the existing process framework rather than adding completely separate steps, device reliability is improved while minimizing impact on manufacturing throughput.
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
This solution significantly minimizes copper contamination and maintains a high dielectric breakdown voltage, reducing the risk of device failure and ensuring reliable performance in high-frequency applications.
Implementation Method 1
The surface of the dielectric layer is treated by nitrogenous gas, such that a thin nitrogenous film is formed over the dielectric layer, and a portion of the dielectric layer is permeated by nitrogenous gas
Data Source
AI summary
A structure includes a semiconductor substrate, a conductor-insulator-conductor capacitor. The conductor-insulator-conductor capacitor is disposed on the semiconductor substrate and includes a first conductor, a nitrogenous dielectric layer and a second conductor. The nitrogenous dielectric layer is disposed on the first conductor and the second conductor is disposed on the nitrogenous dielectric layer.