Semiconductor Capacitor Adhesion via Intermediate Alloy Layer
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Solution Overview
Problem
The semiconductor device experiences a capacitor stripping phenomenon due to poor adhesion at the interface between the oxygen barrier film and the lower electrode, leading to peeling off of the capacitor, which affects the integration and performance of ferroelectric memory devices.
Innovation Solution
A semiconductor device is designed with an intermediate layer made of an alloy containing elements from both the oxygen barrier film and the lower electrode, which is formed at the interface between the oxygen barrier film and the lower electrode, improving adhesion and preventing the capacitor stripping phenomenon. The manufacturing method involves forming an interlayer insulating film, conductive plugs, an oxygen barrier film, a lower electrode, and a dielectric film, with the intermediate layer being deposited through heat treatment to ensure uniform orientation and crystallinity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an oxygen barrier film is formed under the lower electrode to prevent oxidation of the conductive plug, then oxidation protection is improved, but adhesion between the oxygen barrier film and lower electrode deteriorates, causing capacitor stripping
Solution Approach 1:
An intermediate layer is introduced between the oxygen barrier film and the lower electrode to serve as a mediator that improves adhesion while allowing the oxygen barrier film to maintain its oxidation protection function. The intermediate layer contains at least one element from the oxygen barrier film and at least one element from the lower electrode, creating a gradient structure that bridges the two materials and prevents capacitor stripping.
Solution Approach 2:
The intermediate layer is formed as a composite material containing elements from both the oxygen barrier film and the lower electrode. This composite structure combines the oxidation resistance properties of the oxygen barrier film with the adhesion properties of the lower electrode material, resolving the contradiction between protection and bonding strength.
2Device complexity
If material is selected to provide both barrier function and lower electrode function, then device complexity is reduced, but adhesion and oxidation protection cannot be optimized simultaneously
Solution Approach 1:
The structure is segmented into distinct functional layers: an oxygen barrier film for oxidation protection, an intermediate layer for adhesion enhancement, and a lower electrode for electrical function. This segmentation allows each layer to be optimized for its specific function, with the intermediate layer specifically designed to bridge the oxygen barrier film and lower electrode, achieving both protection and adhesion simultaneously.
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 intermediate layer enhances the adhesion between the oxygen barrier film and the lower electrode, preventing capacitor peeling and improving the crystallinity and orientation of the ferroelectric film, thereby enhancing the switching characteristics and reliability of the ferroelectric capacitors.
Implementation Method 1
the intermediate layer being deposited through heat treatment to ensure uniform orientation and crystallinity
Implementation Method 2
an intermediate layer disposed at an interface between the oxygen barrier film and the lower electrode and made of alloy which contains at least one constituent element of the oxygen barrier film and at least one constituent element of the lower electrode
Implementation Method 3
The crystalline structure is transformed into a perovskite structure or a bismuth layer structure by succeeding heat treatment
Data Source
AI summary
An interlayer insulating film (22) is formed on a semiconductor substrate. A conductive plug (25) is embedded in a via hole formed through the interlayer insulating film. An oxygen barrier conductive film (33) is formed on the interlayer insulating film and being inclusive of an area of the conductive plug as viewed in plan. A capacitor (35) laminating a lower electrode, a dielectric film and an upper electrode in this order is formed on the oxygen barrier film. An intermediate layer (34) is disposed at an interface between the oxygen barrier film and the lower electrode. The intermediate layer is made of alloy which contains at least one constituent element of the oxygen barrier film and at least one constituent element of the lower electrode.