Rectangular Germanide Contact Structure for FinFET Source/Drain
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The implementation of FinFETs in CMOS fabrication is hindered by high contact resistance in source/drain regions due to silicide formation on strained materials, which degrades device performance.
Innovation Solution
A contact structure with a rectangular germanide is formed instead of the traditional triangular germanide, providing a low-resistance intermediate layer by adjusting the metal layer deposition and thermal annealing processes to enhance contact resistance and device performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional silicide formation process is used on strained materials, then device fabrication is simplified, but contact resistance increases and device performance degrades
Solution Approach 1:
The patent changes the material parameter from traditional silicide to germanide, and modifies the formation process parameters including metal layer deposition thickness (5-20 nm) and thermal annealing conditions (400-600°C for 30-120 seconds). These parameter changes enable the formation of a rectangular germanide contact structure that provides low resistance path while maintaining compatibility with strained material FinFET fabrication
Solution Approach 2:
The patent introduces germanide as an intermediate layer between the metal contact and the strained source/drain region. This intermediate germanide layer serves as a mediator that prevents the harmful silicide formation on strained materials while providing excellent electrical contact, thus resolving the contradiction between ease of manufacture and contact resistance
2Reliability
If triangular germanide structure is formed, then fabrication process is conventional, but contact resistance remains high and device performance is limited
Solution Approach 1:
The patent transitions from the conventional triangular germanide structure to a rectangular germanide contact structure. This asymmetric geometric change increases the contact area with the strained source/drain region, providing a larger low-resistance path and significantly improving device performance beyond what the symmetric triangular structure could achieve
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 contact structure with a rectangular germanide reduces contact resistance in the source/drain regions, thereby improving the overall performance of FinFETs by providing a low-resistance path for interconnection.
Implementation Method 1
heating the substrate to form a germanide over the facet of the first fin, facet of the second fin, and planar surface of the third fin
Data Source
AI summary
The disclosure relates to a semiconductor device. An exemplary structure for a contact structure for a semiconductor device comprises a substrate comprising a major surface; a fin structure extending upward from the substrate major surface, wherein the fin structure comprises a first fin, a second fin, and a third fin between the first fin and second fin; a first germanide over the first fin, wherein a first bottom surface of the first germanide has a first acute angle to the major surface; a second germanide over the second fin on a side of the third fin opposite to first germanide substantially mirror-symmetrical to each other; and a third germanide over the third fin, wherein a third bottom surface of the third germanide has a third acute angle to the major surface less than the first acute angle.