Through Hole Etching Protection via Selective Insulating Layers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional semiconductor device manufacturing techniques face challenges with over-etching during the removal of insulating layers, leading to poor reliability due to the difficulty in balancing etching time, speed, and thickness, which results in incomplete or excessive etching of insulating layers on the sidewalls and outside the through hole.
Innovation Solution
A method involving a high coverage rate first insulating layer, such as silicon dioxide, is formed on the substrate, and a second insulating layer, like silicon nitride, is deposited outside the through hole to protect the first layer from over-etching during the etching process, ensuring complete etching at the bottom while preventing over-etching on the sidewalls and outside areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the insulating layer at the bottom of the through hole is removed by an etching process to expose the contact pad, then the contact pad can be accessed for connection, but an over-etching problem occurs resulting in poor reliability of the semiconductor device
Solution Approach 1:
A protective layer is formed in advance at the bottom of the through hole before the etching process. This preliminary protective structure prevents the etching solution from directly attacking the contact pad, allowing the insulating layer to be removed without risking over-etching damage to the contact pad, thus resolving the contradiction between achieving complete insulating layer removal and preventing contact pad damage
Solution Approach 2:
The protective layer acts as an intermediary between the etching solution and the contact pad. It enables the etching process to proceed aggressively to remove the insulating layer while the protective layer absorbs the harmful etching action, preventing direct damage to the contact pad and ensuring device reliability
2Manufacturing precision
If the insulating layer is completely removed at the bottom of the through hole, then the contact pad is fully exposed for connection, but the insulating layer on the sidewall and outside the through hole may be over-etched
Solution Approach 1:
The protective layer is selectively formed only at the bottom of the through hole where the contact pad is located, rather than uniformly across the entire substrate. This localized protective structure allows the etching process to completely remove the insulating layer at the bottom while the protective layer prevents over-etching of the insulating layer on the sidewall and outside areas, resolving the contradiction between complete removal and preventing over-etching damage
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 approach improves the reliability of semiconductor devices by ensuring complete etching of the insulating layer at the bottom of the through hole without damaging the sidewall and outside layers, thereby enhancing the structural integrity and functionality of the devices.
Implementation Method 1
forming a first insulating layer, where the first insulating layer covers the bottom and all sidewall of the through hole and the back surface of the substrate outside the through hole
Implementation Method 2
forming a second insulating layer, where the second insulting layer covers the first insulating layer outside the through hole
Implementation Method 3
removing the first insulating layer at the bottom of the through hole by an etching process to expose the contact pad
Data Source
AI summary
A semiconductor device and a manufacture method of the semiconductor device are provided. In the semiconductor device, a back surface of a substrate is covered with a first insulating layer, where the first insulating layer covers the bottom and the sidewall of a through hole and the back surface of the substrate outside the through hole. The first insulating layer outside the through hole is covered with a second insulating layer. When etching the first insulating layer at the bottom of the through hole, although an etching speed for a region outside the through hole is greater than an etching speed for the bottom of the through hole, the first insulating layer outside the through hole is protected from being over-etched by the second insulating layer, which improves reliability of the device.