Semiconductor Die Pad Structure for Single-Etch Test Overlay
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Solution Overview
Problem
The formation of temporary conductive structures during semiconductor die manufacturing results in varying step heights between interconnect pad structures, leading to reduced pick-and-place tool capability and increased damage risk due to low contact force.
Innovation Solution
Utilizing an anti-reflective coating layer composition that allows for the formation of temporary conductive structures with a single etch cycle, reducing step height differences and maintaining consistent contact force for reliable pick-and-place operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple etch cycles are used to form temporary conductive structures, then the anti-reflective coating is completely removed allowing for thorough testing, but the step height difference between interconnect pad structures increases causing low contact force and pick-and-place tool failure
Solution Approach 1:
The patent applies local quality by making the anti-reflective coating selectively removable. The coating is configured to be removed only in specific regions where temporary conductive structures are formed, while remaining intact in other areas. This localized removal allows complete testing access without creating excessive step heights that would compromise pick-and-place operations.
Solution Approach 2:
The patent applies preliminary action by pre-configuring the anti-reflective coating with a specific composition and thickness that enables single-cycle removal. The coating is designed beforehand to have the precise properties needed for complete removal in one etch cycle, preventing the need for multiple cycles that would create damaging step heights.
2Ease of operation
If a single etch cycle is used to form temporary conductive structures, then step height differences are minimized maintaining good pick-and-place contact, but the anti-reflective coating may not be completely removed reducing testing effectiveness
Solution Approach 1:
The patent applies parameter changes by precisely controlling the anti-reflective coating's composition and thickness parameters. The coating is formulated with specific material properties and thickness values that enable complete removal in a single etch cycle, achieving both thorough testing access and minimal step height differences for reliable pick-and-place operations.
3Reliability
If multiple etch cycles are performed, then temporary conductive structures can be fully formed, but manufacturing complexity and process time increase
Solution Approach 1:
The patent applies preliminary action by pre-configuring the anti-reflective coating with a specific composition and thickness that enables single-cycle removal. The coating is designed beforehand to have the precise properties needed for complete removal in one etch cycle, preventing the need for multiple cycles that would create damaging step heights.
Solution Approach 2:
The patent applies merging by combining the anti-reflective coating removal and temporary conductive structure formation into a single integrated etch cycle. This consolidation eliminates the need for separate processing steps, reducing manufacturing complexity and improving productivity while ensuring complete structure formation.
Data Source
AI summary
Some implementations herein include a semiconductor die and methods of formation. The semiconductor die includes an array of interconnect pad structures, including interconnect pad structures having surfaces located within an overlay region of an active device area of the semiconductor die. As part of manufacturing the semiconductor die, temporary conductive structures are formed across the overlay region to support wafer acceptance testing and/or circuit probe testing process. Forming the temporary conductive structures includes using an anti-reflective coating layer having a composition that enables the temporary conductive structures to be formed using a single etch cycle. Relative to other semiconductor dies manufactured using temporary conductive structures formed using an anti-reflective coating layer having another composition (and that may require multiple etch cycles), the semiconductor die includes a reduced difference in step heights between interconnect pad structures in the overlay region and other regions of the active device area.