Ferroelectric Capacitor Oxidation Suppression via Dummy Structure
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Solution Overview
Problem
High interface resistance between the contact plug and the bottom electrode of ferroelectric capacitors in semiconductor devices, caused by plasma-generated charged particles during manufacturing, leading to increased oxidation and reduced charging/discharging times.
Innovation Solution
Incorporation of a real capacitor oxidation suppression structure, which includes a dummy ferroelectric capacitor and a second plug, diverting plasma-generated charged particles away from the real capacitor, thereby reducing current flow and oxidation of the junction between the contact plug and the bottom electrode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a contact plug is formed to electrically connect the bottom electrode of the ferroelectric capacitor to the semiconductor substrate, then electrical connection is achieved, but high interface resistance occurs due to oxidation caused by plasma-generated charged particles
Solution Approach 1:
A dummy ferroelectric capacitor is introduced as an intermediary structure to intercept plasma-generated charged particles before they reach the real ferroelectric capacitor's contact plug. The dummy capacitor's bottom electrode serves as a sacrificial path that absorbs the harmful charged particles, preventing oxidation at the critical interface of the real capacitor.
Solution Approach 2:
The harmful charged particles generated during plasma processing are redirected to the dummy ferroelectric capacitor instead of being harmful to the real capacitor. The dummy capacitor absorbs these charged particles and converts the potentially damaging effect into a controlled process outcome, protecting the real capacitor's contact interface.
2Loss of time
If the interface resistance between the contact plug and bottom electrode is reduced, then charging/discharging time improves, but oxidation occurs due to plasma processing
Solution Approach 1:
The dummy ferroelectric capacitor acts as a protective intermediary that shields the real capacitor's contact interface from oxidation during plasma processing. By providing an alternative path for charged particles, it maintains the low interface resistance needed for fast charging/discharging while preventing oxidation that would otherwise increase resistance.
Solution Approach 2:
The dummy ferroelectric capacitor is formed in advance during the same manufacturing process to preemptively protect the real capacitor. Its presence during plasma processing预先 establishes a protective mechanism that prevents oxidation before it can affect the real capacitor's performance.
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 solution effectively decreases the interface resistance between the contact plug and the bottom electrode, improving the charging/discharging times of ferroelectric capacitors by minimizing oxidation, thus enhancing the performance of semiconductor devices.
Implementation Method 1
when plasma is generated in a semiconductor device manufacturing process, charged particles in the plasma pass through a first conductive path that includes the bottom electrode of the real ferroelectric capacitor
Implementation Method 2
the junction between the first plug and the bottom electrode of the real ferroelectric capacitor is oxidized to increase the interface resistance
Data Source
AI summary
Provided is a semiconductor device that has a low interface resistance between a contact plug and a bottom electrode of a real ferroelectric capacitor. A real capacitor oxidation suppression structure ST including a dummy ferroelectric capacitor 312 and a second plug 311 is formed. The dummy ferroelectric capacitor 312 includes a second bottom electrode 51, a second ferroelectric film 52, and a second top electrode 53, and is not used as a nonvolatile memory element. The second bottom electrode 51 is formed on an interlayer insulating film 50. The second ferroelectric film 52 is formed on the second bottom electrode 51. The second top electrode 53 is formed on the second ferroelectric film 52. The second plug 311 penetrates the interlayer insulating film 50 and electrically connects the second bottom electrode 51 to a semiconductor substrate 40.