Thermally Oxidized TiN Capacitor Interface for Delamination Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Capacitance structures with conductive and high-κ dielectric layers face instability issues due to differences in thermal expansion and microstructure, leading to delamination, particularly in TiN/ZAZ stacks, which affects the reliability of on-chip capacitors in IC devices.
Innovation Solution
A compositionally graded film is formed by thermal oxidation of the conductive layer, creating a gradual transition from the conductive layer to the high-κ dielectric layer, reducing stress-induced wafer bending and delamination through stress relaxation, improved adhesion, and stress distribution mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a conductive layer and high-κ dielectric layer are formed in a capacitance structure, then the capacitance density is improved, but delamination occurs due to thermal expansion mismatch and microstructure differences
Solution Approach 1:
A compositionally graded film is introduced as an intermediary layer between the conductive layer and the high-κ dielectric layer. This graded film contains a composition that gradually transitions from the conductive layer material to the dielectric layer material, reducing the abrupt thermal expansion mismatch and improving interfacial adhesion to prevent delamination
Solution Approach 2:
The composition of the film is gradually changed across the interface between the conductive layer and dielectric layer. By varying the material composition parameter continuously rather than having an abrupt transition, the thermal expansion coefficient mismatch is reduced, and adhesion is improved throughout the transition region
2Ease of manufacture
If conductive and dielectric layers are deposited directly together, then the manufacturing process is simple, but stress-induced wafer bending occurs due to thermal expansion differences
Solution Approach 1:
The compositionally graded film serves as a mediator that buffers the stress between the conductive layer and dielectric layer. By providing a gradual composition transition, it reduces the cumulative stress that causes wafer bending while adding only a thin intermediate layer to the structure
Solution Approach 2:
The interface region between the conductive layer and dielectric layer is segmented into multiple compositional zones within the graded film. This segmentation allows the stress to be distributed across multiple gradual transitions rather than concentrated at a single abrupt interface, reducing overall wafer bending
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 compositionally graded film effectively suppresses delamination and wafer bending, enhancing the stability and reliability of capacitance structures by providing a gradual transition and stress relaxation, thereby improving the performance and yield of on-chip capacitors.
Implementation Method 1
reducing stress-induced wafer bending and delamination through stress relaxation, improved adhesion, and stress distribution mechanisms
Implementation Method 2
A compositionally graded film is formed by thermal oxidation of the conductive layer, creating a gradual transition from the conductive layer to the high-κ dielectric layer
Data Source
AI summary
A capacitance structure comprises a metal nitride layer, such as a titanium nitride (TiN) layer, a compositionally graded film formed on a surface of the metal nitride layer by thermal oxidation, and a dielectric layer disposed on the compositionally graded film. A method of manufacturing a capacitance structure includes forming a conductive layer, performing thermal oxidation of a surface of the conductive layer to produce a compositionally graded film on the conductive layer, and forming a dielectric layer on the compositionally graded film.