Selective Deposition Interconnect Structure via Passivation Layer
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Solution Overview
Problem
The challenge in semiconductor manufacturing lies in forming reliable interconnects with sub-100 nm features, where capacitive coupling between metal interconnects leads to cross-talk and resistance-capacitance delay, and high via resistance due to poor conductive layer formation, affecting electrical performance and circuit density.
Innovation Solution
A method involving the formation of an interconnect structure with selective deposition of metal containing materials in vias and trenches, using passivation layers such as oxide, nitride, or methyl group containing layers to enhance deposition and reduce contact resistance, involving multiple depositions and etching processes to achieve desired material placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If dual damascene structures are formed with stacked dielectric and conductive layers, then multilevel interconnect structures are achieved, but via resistance increases due to interface contact among conductive layers, barrier layers and bulk dielectric insulating layers
Solution Approach 1:
A passivation layer is introduced as an intermediary between the conductive layer and the bulk dielectric insulating layer. This passivation layer serves as a mediator that improves interface contact quality and reduces via resistance, while allowing the dual damascene multilevel interconnect structure to be maintained.
Solution Approach 2:
The interface contact properties are modified by changing the material composition and structure at the interface. The passivation layer alters the physical and chemical parameters of the interface between conductive and dielectric layers, thereby reducing contact resistance and improving via electrical performance.
2Ease of manufacture
If conductive layers are deposited in dual damascene structures, then interconnect functionality is achieved, but contact resistance increases due to poor nucleation and irregular growth
Solution Approach 1:
The passivation layer is formed in advance before the conductive layer deposition. This preliminary action prepares the surface with appropriate nucleation properties, ensuring that the subsequent conductive layer deposition proceeds with uniform growth and good adhesion, thereby reducing contact resistance.
Solution Approach 2:
The surface properties are modified by the passivation layer to optimize nucleation conditions. This changes the physical and chemical parameters of the substrate surface, enabling better nucleation and more regular growth of the conductive layer, which reduces contact resistance.
3Object-affected harmful factors
If metal interconnects are electrically isolated by dielectric bulk insulating material, then capacitive coupling is reduced, but via and trench formation complexity increases
Solution Approach 1:
The opening structure is segmented into distinct via and trench regions, with the passivation layer selectively applied to specific interfaces. This segmentation allows for targeted reduction of capacitive coupling at critical interfaces while maintaining the overall insulating structure.
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 improves electrical performance by reducing via resistance and contact resistance, thereby enhancing the reliability and integration of semiconductor devices, particularly in dual damascene structures.
Implementation Method 1
selectively depositing a first metal containing material in the via
Implementation Method 2
forming a first passivation layer in the opening, removing a portion of the first passivation layer from the opening
Data Source
AI summary
Embodiments of the present disclosure generally relate an interconnect structure formed on a substrate and a method of forming the interconnect structure thereon. In one embodiment, a method of forming an interconnect structure includes forming an opening comprising a via and a trench in an insulating structure formed on a substrate, forming a first passivation layer in the opening, removing a portion of the first passivation layer from the opening, and selectively depositing a first metal containing material in the via.