Transistor Channel Segmentation for ON Current and Leakage Trade-off

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional transistors face a trade-off between maintaining high ON current and low OFF leakage current, as lowering the threshold voltage increases both ON current and OFF leakage current, making it difficult to achieve both simultaneously.

Innovation Solution

A transistor design with a channel region having two portions, one with a lower threshold voltage for increased ON current and another with a higher threshold voltage to maintain low OFF current, achieved through selective doping and positioning within the channel region.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the threshold voltage is lowered to increase ON current, then the ON current increases, but the OFF leakage current also increases

Engineering Contradiction:

ImproveON currentVSAvoidOFF leakage current

Core Design Contradiction:

PowerVSObject-generated harmful factors

Solution Approach 1:

The channel region is divided into two distinct portions: a first portion with a lower threshold voltage to enable high ON current, and a second portion with a higher threshold voltage to suppress OFF leakage current. This segmentation allows each portion to independently optimize for its specific function, resolving the contradiction between high ON current and low OFF leakage current that plagues conventional single-threshold-voltage transistors.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the channel are assigned different doping concentrations to create local variations in threshold voltage. The first portion receives a first doping concentration optimized for low threshold voltage and high current conduction, while the second portion receives a second doping concentration optimized for high threshold voltage and low leakage. This local quality differentiation enables simultaneous optimization of both ON and OFF state performance.

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 design effectively increases ON current while keeping OFF leakage current low, with the higher threshold voltage portion acting as an insulator to block leakage current, reducing it by a factor of five while increasing ON current by 35% compared to traditional designs.

Implementation Method 1

The first portion has a first doping concentration and the second portion has a second doping concentration. The first doping concentration is less than the second doping concentration.

Methodology Applied

Scientific EffectDoping: Dopants

Data Source

PatentUS7843018B2Transistor providing different threshold voltages and method of fabrication thereof

Publication Date: 2010.11.30 MIE FUJITSU SEMICON LTD

AI summary

A transistor includes a channel region with a first portion and a second portion. A length of the first portion is smaller than a length of the second portion. The first portion has a higher threshold voltage than the second portion. The lower threshold voltage of the second portion allows for an increased ON current. Despite the increase attained in the ON current, the higher threshold voltage of the first portion maintains or lowers a relatively low OFF current for the transistor.