3D Comb-Structure MIM Capacitor for Higher Capacitance Density
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Increasing the capacitance of MIM capacitors in semiconductor devices without reducing the areal density of the devices is desired, as larger plate areas typically reduce the density of devices that can be fabricated on a substrate.
Innovation Solution
Fabricating MIM capacitors with a comb structure that increases the effective area without increasing the footprint, achieved by forming trenches and tines in the dielectric layer, and using high-k dielectric materials to enhance capacitance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the plate area of MIM capacitors is increased to enhance capacitance, then capacitance value is improved, but areal density of devices is reduced
Solution Approach 1:
The patent transitions from a conventional planar parallel-plate capacitor structure to a three-dimensional stacked structure with multiple capacitor units arranged vertically. This dimensional change allows capacitance to be increased without proportionally increasing the horizontal footprint, thereby maintaining areal density while achieving higher total capacitance through vertical stacking of multiple capacitor units sharing common electrodes.
Solution Approach 2:
The capacitor structure is segmented into multiple discrete capacitor units stacked vertically, with shared common electrodes between adjacent units. Each capacitor unit can be independently formed and controlled, allowing the total capacitance to be the sum of individual unit capacitances while occupying the same horizontal area, thus resolving the contradiction between capacitance value and areal density.
2Ease of manufacture
If conventional parallel plate structure is used, then manufacturing is simple, but capacitance per unit area is limited
Solution Approach 1:
Multiple capacitor units are nested vertically in a stacked configuration, with lower electrodes of upper capacitor units serving as upper electrodes of lower capacitor units. This nesting arrangement maximizes the use of vertical space and allows multiple capacitance elements to occupy the same horizontal footprint, significantly increasing capacitance per unit area while maintaining compatibility with standard semiconductor manufacturing processes.
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 comb structure design allows for a 1.1× to 3× increase in capacitance without reducing areal density, making it suitable for applications like CMOS image sensors requiring high capacitance without increasing device size.
Implementation Method 1
using high-k dielectric materials to enhance capacitance
Data Source
AI summary
Metal-insulator-metal (MIM) capacitor, an integrated semiconductor device having a MIM capacitor and methods of making. The MIM capacitor includes a first metal layer, a second metal layer and a dielectric layer located between the second metal layer and the first metal layer. The first metal layer, the second metal layer and the dielectric layer may be formed in a comb structure, wherein the comb structure include a first tine structure and at least a second tine structure.