TSV Dielectric Structure With Etch Stop for Pad Alignment Reliability
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Solution Overview
Problem
Existing semiconductor packages face challenges in achieving efficient stacking and connection of semiconductor chips with through vias (TSV) due to issues in dielectric structure design and pad formation, leading to potential reliability concerns.
Innovation Solution
A semiconductor package design featuring a dielectric structure with an etch stop pattern and specific pad configurations, including a first dielectric pattern, etch stop pattern, and second dielectric pattern, which ensures proper alignment and contact between pads and through electrodes, enhancing reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a through electrode penetrates the semiconductor substrate with a simple dielectric structure, then the manufacturing process is simpler, but the alignment and connection reliability between pads and through electrodes deteriorates
Solution Approach 1:
The dielectric structure is segmented into multiple distinct patterns: a first dielectric pattern in the lower portion, a second dielectric pattern in the upper portion, and an etch stop pattern between them. This segmentation allows each layer to serve specific functions - the first dielectric pattern provides support and alignment reference, the etch stop pattern prevents over-etching, and the second dielectric pattern provides insulation and structural support, collectively improving connection reliability without significantly complicating manufacturing
Solution Approach 2:
The etch stop pattern is formed preliminarily between the first and second dielectric patterns to establish a controlled interface. This preliminary action ensures that during subsequent etching processes, the etching stops at the predetermined location, preventing damage to the through electrode and ensuring precise alignment. The preliminary formation of this protective layer maintains manufacturing simplicity while guaranteeing connection reliability
2Reliability
If the top surface of the through electrode is at a higher level than the top surface of the first dielectric pattern, then the pad contact area is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The etch stop pattern acts as an intermediary element between the first dielectric pattern and the through electrode. It provides a controlled interface that allows the through electrode to protrude above the first dielectric pattern while preventing direct contact between the electrode and the first dielectric pattern. This intermediary structure improves pad contact reliability by creating a stable, controlled interface without requiring extremely tight manufacturing tolerances
Solution Approach 2:
The dielectric structure exhibits local quality variations with different patterns serving different functions at different locations. The first dielectric pattern provides support in the lower portion, the etch stop pattern provides controlled stopping and interface formation in the middle, and the second dielectric pattern provides insulation and support in the upper portion. This localized functional differentiation allows the through electrode to be positioned at a higher level for better pad contact while maintaining overall manufacturing feasibility
3Reliability
If the second dielectric pattern is spaced apart from the first dielectric pattern by the etch stop pattern, then the pad lateral surface protection is improved, but the device complexity increases
Solution Approach 1:
The dielectric structure is divided into functionally distinct segments: the first dielectric pattern for lower support, the etch stop pattern for interface control, and the second dielectric pattern for upper support and lateral protection. This segmentation allows the second dielectric pattern to be spaced apart from the first by the etch stop pattern, creating physical separation that protects the pad lateral surface while maintaining structural integrity. The modular nature of this segmented design actually simplifies manufacturing by allowing each segment to be formed and optimized independently
Solution Approach 2:
The etch stop pattern serves as an intermediary layer that physically separates the first and second dielectric patterns. This intermediary structure protects the pad lateral surface by preventing direct contact between the pad and the first dielectric pattern, while also providing a controlled interface for the through electrode. Although this adds a layer to the structure, it uses standard dielectric materials and formation processes, so the actual manufacturing complexity increase is minimal while the reliability improvement is significant
Data Source
AI summary
A semiconductor package includes: a semiconductor substrate; a through electrode that penetrates the semiconductor substrate; a first pad disposed on the through electrode; and a dielectric structure disposed on the semiconductor substrate, wherein a lower portion of the dielectric structure at least partially surrounds the through electrode, wherein an upper portion of the dielectric structure at least partially surrounds the first pad, wherein the dielectric structure includes: a first dielectric pattern; an etch stop pattern disposed on the first dielectric pattern; and a second dielectric pattern spaced apart from the first dielectric pattern by the etch stop pattern, wherein the first pad is in contact with the through electrode, the first dielectric pattern, the etch stop pattern, and second dielectric pattern, and wherein a top surface of the through electrode is at a level higher than a level of a top surface of the first dielectric pattern.