Graduated Capacitor Structure Using Multi-Depth Bottom Electrodes

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Solution Overview

Problem

The manufacturing of semiconductor capacitors with varying capacitance values is time-consuming and prone to corrosion due to long etching processes, which expose metals to remnant etching gases, leading to defects and increased manufacturing times.

Innovation Solution

A graduated capacitor structure with multiple bottom electrodes at different depths and a shared top electrode is designed, allowing for the creation of capacitors with distinct capacitance values through varying distances and CMP processes, minimizing exposure to corrosive gases and reducing manufacturing steps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional capacitor manufacturing processes are used to create capacitors with varying capacitance values, then precise capacitance tuning is achieved, but manufacturing time increases significantly

Engineering Contradiction:

Improvecapacitance tuning precisionVSAvoidmanufacturing time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The capacitor structure is segmented into multiple bottom electrodes at different depths within the dielectric layer, each forming a capacitor with the shared top electrode. This segmentation allows different capacitance values to be achieved through structural variation rather than time-consuming process tuning.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention transitions from varying capacitance through process parameters (time, temperature) to varying capacitance through spatial dimension - specifically, the vertical depth positioning of bottom electrodes at different levels within the dielectric layer creates distinct capacitance values.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Manufacturing precision

If long etching processes are used to create graduated capacitor structures, then capacitors with distinct capacitance values are formed, but corrosion occurs due to exposure to remnant etching gases

Engineering Contradiction:

Improvecapacitance value distinctionVSAvoidcorrosion resistance

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The graduated capacitor structure is formed using deposition and planarization processes before any etching steps. The bottom electrodes are created at different depths through controlled deposition and CMP, establishing the capacitance values prior to etching, thereby eliminating prolonged metal exposure to etching gases.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Instead of using etching to create the graduated structure (which causes corrosion), the invention inverts the approach by using deposition and planarization to build the graduated structure, then using minimal etching only for contact via formation.

Inventive Principle:

Principle #13The other way round (Inversion)

3Measurement precision

If multiple separate manufacturing steps are used for each capacitor variant, then precise capacitance control is achieved, but device complexity and manufacturing time increase

Engineering Contradiction:

Improvecapacitance control precisionVSAvoidmanufacturing process complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

Multiple capacitors with different capacitance values are merged into a single integrated structure sharing common top electrode and dielectric layer. The different capacitance values are achieved by positioning bottom electrodes at different depths within the same dielectric layer, eliminating the need for separate manufacturing steps for each capacitor variant.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The shared top electrode and dielectric layer structure serves multiple functions simultaneously - it forms the common element for all capacitors while the varying bottom electrode depths provide different capacitance values, creating a multi-functional structure that reduces overall process complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

This approach reduces manufacturing time and minimizes corrosion, enabling precise capacitance tuning and improved reliability of semiconductor devices by standardizing the production of capacitors with different capacitance values.

Implementation Method 1

performing chemical mechanical polishing (CMP)

Methodology Applied

Scientific EffectChemical Mechanical Polishing:

Data Source

PatentUS12191247B2Variable graduated capacitor structure and methods for forming the same

Publication Date: 2025.01.07 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

Devices and methods of manufacture for a graduated, “step-like,” capacitance structure having two or more capacitors. A semiconductor structure comprising a capacitor structure, the capacitor structure comprising a first capacitor and a second capacitor. The first capacitor comprising a first bottom electrode and a top electrode having a bottom surface that is a first distance from a top surface of the first bottom electrode. The second capacitor comprising a second bottom electrode and the top electrode, in which the bottom surface is a second distance from a top surface of the second bottom electrode, and in which the first distance is different from the second distance.