Semiconductor Test Structure With Dielectric Region For High Voltage Testing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current semiconductor chip testing methods are limited by the breakdown voltage of metal layers, restricting the application of high test voltages and potentially leading to inaccurate device parameter measurements.
Innovation Solution
A semiconductor structure design that includes a test structure with a metal/dielectric layer configuration where the test structure is positioned over a dielectric region void of metal, allowing for higher test voltages without breaking down the metal layers, and metal lines aligned with isolation features to prevent overlap with active regions, enabling ultra-high voltage testing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metal layers are used in the test structure, then electrical connectivity is achieved, but the test voltage is limited by metal layer breakdown
Solution Approach 1:
A dielectric layer is introduced as an intermediary material between the test structure electrodes and the metal layers. This dielectric layer has higher breakdown voltage characteristics than the metal layers, allowing high voltage testing without causing metal layer breakdown. The dielectric layer mediates the electrical stress, preventing direct breakdown of the metal interconnects.
Solution Approach 2:
The patent changes the material parameter (breakdown voltage) by replacing metal layers with a dielectric layer in specific regions of the test structure. This parameter change enables the structure to withstand higher test voltages that would otherwise cause breakdown in conventional metal-based test structures.
2Adaptability or versatility
If metal lines extend over active regions, then routing flexibility is improved, but device operation is disrupted
Solution Approach 1:
The test structure is segmented into distinct regions: a first region containing the device under test, and a second region containing the test structure. This segmentation allows metal lines to be routed in the second region without interfering with device operation in the first region. The isolation feature physically separates these functional areas.
Solution Approach 2:
An isolation feature acts as an intermediary barrier between the active regions and the test structure metal lines. This isolation feature prevents direct interaction between the metal lines and the active device regions, allowing flexible routing while maintaining device operation integrity.
3Measurement precision
If test voltage is increased beyond metal breakdown voltage, then measurement accuracy is improved, but metal layers break down
Solution Approach 1:
The dielectric layer serves as a protective intermediary that withstands high test voltages without breaking down. This allows measurement of device parameters at high voltages that would normally cause metal layer breakdown, thereby improving measurement accuracy for high-voltage device characterization.
Solution Approach 2:
The dielectric layer in the test structure region can be considered a sacrificial element that protects the more valuable metal interconnect layers. Once the test is complete, the dielectric region serves its purpose and the structure can be reset or the device can be tested again without damage to the metal layers.
Data Source
AI summary
A semiconductor structure includes a substrate, a device, a contact via, a metal/dielectric layer, and a test structure. The device is over the substrate. The contact via is connected to the device. The metal/dielectric layer is over the contact via. The metal/dielectric layer includes a first portion and a second portion. The first portion of the metal/dielectric layer has a metallization pattern connected to the contact via. The second portion of the metal/dielectric layer is void of metal. The test structure is over the second portion of the metal/dielectric layer.