Through Silicon Via Protection Ring Stress Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The accumulation of thick insulating material layers during the formation of protection rings in semiconductor devices can induce stress and damage to the semiconductor substrate, leading to abnormal device performance.
Innovation Solution
A multi-step process is employed to form a protection ring using a pad oxide layer, nitride layer, and two distinct material layers with different stresses, where the thickness of each layer is carefully controlled to be no more than one-fourth of the opening width, and excess material is removed to prevent excessive stress on the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thick insulating material layer is formed in one step to create the protection ring, then the insulating effect is improved, but stress-induced damage to the semiconductor substrate occurs
Solution Approach 1:
The protection ring formation process is segmented into multiple steps with multiple material layers (first insulating material layer, second insulating material layer, third insulating material layer) instead of forming a single thick layer. Each layer has a thickness less than one-fourth of the opening width, distributing the total thickness and reducing stress accumulation in any single layer while achieving the required insulating effect.
2Reliability
If the thickness of the insulating material layer is increased to improve protection, then the insulating performance is enhanced, but the stress on the substrate increases causing defects
Solution Approach 1:
The thick insulating layer is divided into multiple thinner layers (first, second, and third insulating material layers), each with thickness less than one-fourth of the opening width. This segmentation maintains the total protection thickness while preventing stress-induced substrate damage that would occur with a single thick layer.
Solution Approach 2:
The thickness parameter of each insulating material layer is controlled to be less than one-fourth of the opening width. This parameter change from a single thick layer to multiple thin layers resolves the contradiction between achieving sufficient protection and avoiding substrate stress damage.
3Object-affected harmful factors
If multiple material layers are formed to reduce stress, then the process complexity increases, but the substrate damage is prevented
Solution Approach 1:
The protection ring is formed by segmenting the material deposition into multiple steps with different insulating material layers, each with controlled thickness. This segmentation prevents substrate damage by distributing stress while the systematic multi-layer approach manages the inherent process complexity.
Data Source
AI summary
A method of fabricating a semiconductor device includes the following steps. A semiconductor substrate having a first side and a second side facing to the first side is provided. At least an opening is disposed in the semiconductor substrate of a protection region defined in the first side. A first material layer is formed on the first side and the second side, and the first material layer partially fills the opening. Subsequently, a part of the first material layer on the first side and outside the protection region is removed. A second material layer is formed on the first side and the second side, and the second material layer fills the opening. Then, a part of the second material layer on the first side and outside the protection region is removed. Finally, the remaining first material layer and the remaining second material layer on the first side are planarized.