Integrated Circuit Design: MIM Capacitor and TFR Module Optimization
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Summary
Problems
Conventional MIM capacitor modules suffer from limited top electrode thickness, high series resistance, low quality factor, unpredictable breakdown voltage, and hillock formation, while TFR modules are expensive and require multiple additional mask layers, complicating integrated circuit fabrication.
Innovation solutions
An integrated circuit structure is developed with both MIM capacitor and TFR modules formed concurrently between two metal layers, utilizing a damascene process to create cup-shaped electrodes and resistor elements, using refractory metals like tungsten and titanium nitride to prevent hillocks and ensure uniform insulator thickness for improved performance.
TRIZ Analysis
Specific contradictions:
General conflict description:
Principle concept:
If the top electrode thickness is increased to reduce series resistance, then the quality factor improves, but the top electrode etch process margin becomes extremely narrow and difficult to control
Why choose this principle:
The top electrode is segmented into two distinct layers: a first top electrode layer (TiN) deposited to a controlled thickness, and a second top electrode layer (aluminum) deposited subsequently. This segmentation allows the resistive function to be separated from the etch-stop function, enabling thicker effective top electrode for lower resistance while maintaining etch process control through the distinct TiN/aluminum interface.
Principle concept:
If the top electrode thickness is increased to reduce series resistance, then the quality factor improves, but the top electrode etch process margin becomes extremely narrow and difficult to control
Why choose this principle:
The TiN layer serves as an intermediary between the IMD layer and the aluminum top electrode. It provides a defined etch stop plane that mediates the etching process, allowing precise control of the top electrode thickness independent of the aluminum layer thickness, thus resolving the contradiction between achieving low resistance and maintaining etch margin.
Application Domain
Data Source
AI summary:
An integrated circuit structure is developed with both MIM capacitor and TFR modules formed concurrently between two metal layers, utilizing a damascene process to create cup-shaped electrodes and resistor elements, using refractory metals like tungsten and titanium nitride to prevent hillocks and ensure uniform insulator thickness for improved performance.
Abstract
An integrated circuit structure including a metal-insulator-metal (MIM) capacitor module and a thin-film resistor (TFR) module is provided. The MIM capacitor module includes a bottom electrode base formed in a lower metal layer, a bottom electrode formed in a dielectric region between the lower metal layer and an upper metal layer, an insulator formed over the bottom electrode, and a top electrode formed in the upper metal layer over the insulator. The bottom electrode includes a cup-shaped bottom electrode component and a bottom electrode fill component formed in an interior opening defined by the cup-shaped bottom electrode component. The TFR module includes a pair of metal heads formed in the dielectric region and a resistor element connected across the pair of metal heads. Each metal head includes a cup-shaped head component and a head fill component formed in an interior opening defined by the cup-shaped head component.