Metal Fuse Structure with Damaged Portion for Controlled Blow Location
Solution Overview
Problem
Existing metal fuse structures in microelectronic devices lack control over the location of fuse blow, leading to variability in final resistance due to collateral damage and inefficient current conduction before failure.
Innovation Solution
A fuse structure is designed with a damaged portion in the conductor, aligned under a cap layer opening, allowing for consistent fuse blow at a predetermined location by strategically placing the damage to minimize collateral damage and maintain pre-fuse-blow conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional metal fuse structure is used without intentional damage, then the fuse can conduct current before failure, but the location of fuse blow is uncontrolled leading to variability in final resistance
Solution Approach 1:
The patent applies preliminary action by intentionally creating a damaged portion in the fuse conductor before the fuse is programmed. This pre-damaged region serves as a predetermined failure location that will blow first when high current is applied, ensuring consistent and controlled fuse blow location rather than allowing random failure at unpredictable positions along the conductor.
2Manufacturing precision
If the fuse structure is designed to blow at a specific location, then resistance variability is reduced, but the structure becomes more complex with additional damaged portions
Solution Approach 1:
The patent applies local quality by creating a localized damaged portion at a specific location within the fuse conductor, while the rest of the conductor remains intact with its normal properties. This localized modification introduces minimal complexity changes to the overall fuse structure, as only a small region needs to be altered rather than the entire conductor.
3Reliability
If high current is passed through the fuse structure to induce electromigration, then fuse blow is achieved, but collateral damage to neighboring dielectric material increases
Solution Approach 1:
The patent applies preliminary anti-action by pre-positioning the damaged portion to be the weakest link in the fuse conductor. When high current is applied to induce electromigration and fuse blow, the failure occurs predictably at the pre-damaged location rather than randomly elsewhere, which contains the collateral damage to dielectric material to a localized area around the intended failure point.
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 solution ensures consistent and predictable fuse blow at a controlled location, reducing variability in final resistance and minimizing damage to neighboring dielectric materials.
Implementation Method 1
use the phenomenon of electromigration (EM) to program the fuses
Implementation Method 2
The dielectric properties of the isolation oxide keep in the heat generated by current flow, thus increasing the temperature of the structure
Data Source
AI summary
Structure providing more reliable fuse blow location, and method of making the same. A vertical metal fuse blow structure has, prior to fuse blow, an intentionally damaged portion of the fuse conductor. The damaged portion helps the fuse blow in a known location, thereby decreasing the resistance variability in post-blow circuits. At the same time, prior to fuse blow, the fuse structure is able to operate normally. The damaged portion of the fuse conductor is made by forming an opening in a cap layer above a portion of the fuse conductor, and etching the fuse conductor. Preferably, the opening is aligned such that the damaged portion is on the top corner of the fuse conductor. A cavity can be formed in the insulator adjacent to the damaged fuse conductor. The damaged fuse structure having a cavity can be easily incorporated in a process of making integrated circuits having air gaps.