Lattice-Matched Contact Plug and Seeding Layer for Semiconductor Devices
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Solution Overview
Problem
As semiconductor devices scale down, the critical dimension of contacts decreases, leading to increased contact resistance and various defects, which existing technologies have not adequately addressed.
Innovation Solution
The semiconductor device incorporates a seeding layer with a first crystalline metal and a contact plug with a second crystalline metal, both having a similar crystal structure and lattice constants, to enhance bonding strength and reduce contact resistance, with the contact plug being lattice-matched to the seeding layer to increase grain size and lower resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the critical dimension of contact is scaled down to increase integration density, then device integration density is improved, but contact resistance increases and contact reliability deteriorates
Solution Approach 1:
The contact structure is segmented into multiple layers: a seeding layer and a contact plug layer. This segmentation allows each layer to be optimized for specific functions - the seeding layer for strong adhesion and crystal template provision, and the contact plug for low resistance and lattice matching, thereby resolving the contradiction between miniaturization and contact reliability
Solution Approach 2:
The contact structure uses composite materials with different crystalline properties. The seeding layer and contact plug are made of different crystalline metals that are lattice-matched, creating a composite structure that provides both strong bonding (from the seeding layer) and low contact resistance (from the lattice-matched contact plug), thus improving reliability while maintaining scaled dimensions
2Ease of manufacture
If conventional contact structures are used in scaled-down devices, then manufacturing process simplicity is maintained, but contact plug detachment and defects occur
Solution Approach 1:
The seeding layer is formed in advance before the contact plug is deposited. This preliminary action creates a prepared surface with specific crystalline orientation and adhesion properties that prevent subsequent contact plug detachment and defects, while still using standard deposition processes
Solution Approach 2:
The seeding layer acts as an intermediary between the substrate and the contact plug. It provides a crystalline template and adhesion interface that prevents direct bonding issues between the contact plug and underlying layers, thereby preventing detachment and defects without complicating the overall manufacturing process
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 configuration effectively prevents contact plug detachment during processing, significantly decreases contact resistance, and improves the reliability of semiconductor devices by ensuring strong bonding and low resistance.
Implementation Method 1
The second crystalline metal may be substantially lattice-matched to the first crystalline metal at an interface between the seeding layer and the contact plug
Data Source
AI summary
A semiconductor device includes: a fin-type active region extending on a substrate in a first direction; a gate structure extending across the fin-type active region in a second direction, different from the first direction; a source/drain region in the fin-type active region on one side of the gate structure; and first and second contact structures connected to the source/drain region and the gate structure, respectively, wherein at least one of the first and second contact structures includes a seeding layer on at least one of the gate structure and the source/drain region and including a first crystalline metal, and a contact plug on the seeding layer and including a second crystalline metal different from the first crystalline metal, and the second crystalline metal is substantially lattice-matched to the first crystalline metal at an interface between the seeding layer and the contact plug.