Transistor Source/Drain Contacts With Nitrogen-Tuned Dielectric Isolation
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Solution Overview
Problem
As semiconductor devices continue to shrink in size, the integration of electronic components becomes more challenging, leading to issues such as damage to dielectric materials during etching processes, which affects electrical isolation and performance.
Innovation Solution
A method is introduced to reduce the etch rate of dielectric materials around openings by performing treatment processes, thereby minimizing damage during cleaning and enhancing electrical isolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If dielectric materials are etched during cleaning processes, then contact openings are cleaned effectively, but damage occurs to the dielectric material around the openings
Solution Approach 1:
The patent applies local quality by creating a nitrogen-rich region specifically at the interface between the dielectric material and contact opening. This localized modification allows the dielectric material to resist etching damage during cleaning processes while maintaining normal etchability elsewhere. The nitrogen concentration is highest at the interface where damage prevention is needed and decreases with distance from the interface.
Solution Approach 2:
The patent implements preliminary action by performing nitrogen exposure treatment on the dielectric material before the cleaning etch process. This pre-treatment modifies the dielectric material properties in advance, creating a protective nitrogen-rich layer that prevents damage during subsequent cleaning operations. The nitrogen exposure is performed at a specific stage in the fabrication process to ensure optimal protection during later cleaning steps.
2Productivity
If minimum feature sizes are reduced to increase integration density, then more components can be integrated, but additional fabrication problems arise
Solution Approach 1:
The patent applies parameter changes by modifying the chemical composition of the dielectric material through nitrogen exposure treatment. This changes the etch resistance parameter of the dielectric material locally, allowing it to withstand cleaning processes without damage. By controlling nitrogen concentration as a parameter, the patent enables precise adjustment of material properties to meet the requirements of miniaturized device fabrication.
Data Source
AI summary
In an embodiment, a device includes: a source/drain region over a semiconductor substrate; a dielectric layer over the source/drain region, the dielectric layer including a first dielectric material; an inter-layer dielectric over the dielectric layer, the inter-layer dielectric including a second dielectric material and an impurity, the second dielectric material different from the first dielectric material, a first portion of the inter-layer dielectric having a first concentration of the impurity, a second portion of the inter-layer dielectric having a second concentration of the impurity, the first concentration less than the second concentration; and a source/drain contact extending through the inter-layer dielectric and the dielectric layer to contact the source/drain region, the first portion of the inter-layer dielectric disposed between the source/drain contact and the second portion of the inter-layer dielectric.