MOS Capacitor Tunability via Multi-Region Doping

Solution Overview

Problem

In semiconductor devices with high well doping concentrations, the tuning range of MOS capacitors becomes narrow due to increased minimum capacitance, leading to deteriorated tunability as device sizes scale down.

Innovation Solution

A semiconductor device structure is implemented with a substrate having a first impurity diffusion region and multiple second impurity diffusion regions with different doping concentrations, surrounded by the first region, and electrodes positioned to maximize the capacitance range by varying the impurity concentrations and positions of these regions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a MOS capacitor is formed on a substrate having a relatively high well doping concentration, then the device can achieve high integration and power management functions, but the minimum capacitance increases and the tuning range becomes narrow

Engineering Contradiction:

Improveintegration densityVSAvoidtuning range

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The substrate is divided into multiple impurity diffusion regions with different doping concentrations. A first impurity diffusion region has a first doping concentration, while at least one second impurity diffusion region surrounded by the first region has a second doping concentration different from the first. This segmentation allows different regions to contribute differently to the capacitance characteristics, enabling a broader tuning range even at high overall doping concentrations.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the substrate are given different local doping concentrations to optimize specific functions. The first impurity diffusion region provides the base doping level for high integration, while the second impurity diffusion region with a different doping concentration locally modifies the capacitance characteristics to maintain a wide tuning range. This local quality variation resolves the contradiction between high integration density and broad tuning range.

Inventive Principle:

Principle #3Local quality

2Reliability

If the well doping concentration is increased to meet scaling requirements, then device performance is improved, but the range between maximum and minimum capacitance decreases

Engineering Contradiction:

Improvedevice performanceVSAvoidcapacitance range

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The substrate is divided into multiple impurity diffusion regions with different doping concentrations. A first impurity diffusion region has a first doping concentration, while at least one second impurity diffusion region surrounded by the first region has a second doping concentration different from the first. This segmentation allows different regions to contribute differently to the capacitance characteristics, enabling a broader tuning range even at high overall doping concentrations.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the substrate are given different local doping concentrations to optimize specific functions. The first impurity diffusion region provides the base doping level for high integration, while the second impurity diffusion region with a different doping concentration locally modifies the capacitance characteristics to maintain a wide tuning range. This local quality variation resolves the contradiction between high integration density and broad tuning range.

Inventive Principle:

Principle #3Local quality

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 structure effectively increases the range between maximum and minimum capacitance, enhancing the tunability of MOS capacitors even at high well doping concentrations, preventing the narrowing of the tuning range and improving device performance.

Implementation Method 1

a first impurity diffusion region having a first doping concentration and at least one second impurity diffusion region having a second doping concentration different from the first doping concentration

Methodology Applied

Scientific EffectImpurity diffusion: Diffusion

Data Source

PatentUS9548401B2Semiconductor device

Publication Date: 2017.01.17 SAMSUNG ELECTRONICS CO LTD

AI summary

A semiconductor device includes a substrate including a first impurity diffusion region having a first doping concentration and at least one second impurity diffusion region having a second doping concentration different from the first doping concentration, the at least one second impurity region being surrounded by the first impurity diffusion region; at least one electrode facing the first impurity diffusion region and the at least one second impurity diffusion region; and at least one insulating layer between the first impurity diffusion region and the at least one electrode, and between the at least one second impurity diffusion region and the at least one electrode.