Semiconductor Bond Pad Fluorine Contamination Reduction
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Solution Overview
Problem
The exposure of contact pads in semiconductor devices to fluorine doped interlayer dielectric materials leads to surface contamination due to outdiffusion of fluorine species, especially during prolonged processing times, resulting in inferior contact reliability and increased risk of contact failures.
Innovation Solution
A method is introduced to form a protection layer on the sidewalls of trenches in the scribe lane of semiconductor devices, which reduces the outdiffusion of fluorine species by depositing a material like silicon oxide-based protection layers on the sidewalls and selectively removing it from contact pads, ensuring superior surface conditions and reliability of contact pads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If fluorine doped interlayer dielectric materials are used to reduce RC times, then signal propagation delay is reduced, but contact pad surface contamination increases due to fluorine outdiffusion
Solution Approach 1:
A protection layer is introduced as an intermediary substance between the fluorine doped dielectric material and the contact pad surface. This protection layer acts as a barrier that prevents fluorine species from migrating to and contaminating the contact pad surface, while allowing the fluorine doped dielectric to maintain its low dielectric constant properties for reduced RC times.
Solution Approach 2:
The protection layer is applied in advance before the fluorine outdiffusion problem occurs. By pre-establishing this protective barrier on the contact pad surface or at the interface with the dielectric material, the harmful fluorine migration is prevented before it can degrade the contact pad surface quality.
2Loss of time
If prolonged processing times are used, then manufacturing completeness is improved, but fluorine outdiffusion and contact contamination increase
Solution Approach 1:
The protection layer is applied preliminarily before the prolonged processing steps occur. This pre-established protective barrier remains in place during extended processing times, queue times, or storage periods, continuously preventing fluorine outdiffusion throughout the entire processing duration without requiring additional monitoring or intervention.
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
The protection layer effectively suppresses the outdiffusion of fluorine species, maintaining superior surface conditions of contact pads throughout processing, even with extended queue times, thereby enhancing the reliability and performance of contact pads in semiconductor devices.
Implementation Method 1
The protection layer effectively suppresses the outdiffusion of fluorine species
Implementation Method 2
depositing a material like silicon oxide-based protection layers on the sidewalls
Data Source
AI summary
A method of reducing contamination of contact pads in a metallization system of a semiconductor device. Fluorine contamination of contact pads in a semiconductor device can be reduced by appropriately covering the sidewall portions of a metallization system in the scribe lane in order to significantly reduce or suppress the out diffusion of fluorine species, which may react with the exposed surface areas of the contact pads. The quality of the bond contacts is enhanced, possibly without requiring any modifications in terms of design rules and electrical specifications.