Semiconductor Interconnect Structure With AlN Etch Stop Protection
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Solution Overview
Problem
The miniaturization of semiconductor devices has complicated the formation and structure of interconnects, leading to challenges in preventing oxidation, corrosion, and the formation of hydride and hydroxyl impurities within these interconnects, which affects their efficiency and reliability.
Innovation Solution
The use of an etch stop layer, such as metal-doped aluminum nitride, is implemented between dielectric layers to prevent oxidation and corrosion of conductive lines and to inhibit the formation of impurities, while also allowing for the formation of openings for interconnects without fully exposing the conductive lines, thereby maintaining their integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional photolithographic, etching, deposition, and planarization techniques are used to form interconnections, then interconnects can be formed to connect active and passive devices, but the process becomes more complicated and interconnects are more susceptible to oxidation, corrosion, and impurity formation
Solution Approach 1:
An etch stop layer is deposited over the conductive line before subsequent dielectric layer deposition and processing. This preliminary action creates a protective barrier that prevents oxidation and corrosion of the conductive line during later fabrication steps, eliminating the need for complex protective measures while improving reliability
Solution Approach 2:
The etch stop layer serves as an intermediary between the conductive line and the dielectric layers. This intermediate layer protects the conductive line from direct exposure to oxidizing environments and processing chemicals, preventing impurity formation and corrosion while maintaining a relatively simple fabrication process
2Reliability
If etch stop layer is deposited over conductive line, then oxidation and corrosion are prevented, but additional fabrication steps are required
Solution Approach 1:
The etch stop layer performs multiple functions simultaneously: it protects the conductive line from oxidation and corrosion, serves as a barrier to impurity formation, and provides a defined interface for subsequent dielectric layer deposition. By consolidating these protective and process-control functions into a single layer, the patent achieves high reliability without proportionally increasing process complexity
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
This approach effectively prevents oxidation and corrosion of interconnects and the formation of hydride and hydroxyl impurities, enhancing the reliability and efficiency of semiconductor interconnects by maintaining the integrity of conductive lines during the interconnect formation process.
Implementation Method 1
The use of an etch stop layer, such as metal-doped aluminum nitride, is implemented between dielectric layers to prevent oxidation and corrosion of conductive lines
Implementation Method 2
The use of an etch stop layer, such as metal-doped aluminum nitride, is implemented between dielectric layers to prevent oxidation and corrosion of conductive lines and to inhibit the formation of impurities
Data Source
AI summary
A device includes a substrate, a first dielectric layer over the substrate, a first conductive feature in the first dielectric layer, and an etch stop layer over the first dielectric layer. The etch stop layer includes metal-doped aluminum nitride. The device further includes a second dielectric layer over the etch stop layer, and a second conductive feature in the second dielectric layer. The second conductive feature extends into the etch stop layer and contacts the first conductive feature.