SiCr Resistor Integration in HiK Metal Gate Technologies

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Solution Overview

Problem

Conventional polysilicon resistors in replacement gate technologies for integrated circuits pose challenges in controlling resistor properties without increasing fabrication complexity and cost.

Innovation Solution

Replacing conventional polysilicon resistors with front-end SiCr resistors, which are formed before the first metal interconnect level and integrated with the replacement metal gate, allowing for improved resistor tolerance control and characteristics similar to polysilicon resistors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If polysilicon resistors are used in replacement gate technologies, then the fabrication sequence can be simplified, but resistor tolerance control deteriorates

Engineering Contradiction:

Improvefabrication sequence simplicityVSAvoidresistor tolerance control

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent changes the material parameter from polysilicon to SiCr (silicon chromium) to achieve better resistor tolerance control. By modifying the material composition and properties, the invention maintains compatibility with replacement gate fabrication while significantly improving resistor precision and tolerance control capabilities

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses SiCr, a composite material consisting of silicon and chromium, to replace pure polysilicon. This composite material combines the advantages of both elements to achieve superior resistor characteristics including better tolerance control while remaining compatible with the replacement gate fabrication process

Inventive Principle:

Principle #40Composite materials

2Device complexity

If polysilicon resistors are used in replacement gate technologies, then fabrication complexity is reduced, but resistor characteristics deteriorate

Engineering Contradiction:

Improvefabrication complexityVSAvoidresistor characteristics

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent modifies the material parameter from polysilicon to SiCr to achieve superior resistor characteristics including better tolerance control and reduced self-heating effects. This parameter change maintains fabrication compatibility while significantly improving resistor reliability and performance characteristics

Inventive Principle:

Principle #35Parameter changes

3Power

If polysilicon resistors are used, then current capability is limited, but self-heating increases

Engineering Contradiction:

Improvecurrent capabilityVSAvoidself-heating

Core Design Contradiction:

PowerVSTemperature

Solution Approach 1:

The patent changes the material composition from polysilicon to SiCr to fundamentally alter the resistor's electrical and thermal properties. This material parameter change enables higher current capability while reducing self-heating effects due to the superior electrical conductivity and thermal properties of the SiCr composite material

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS8680618B2Structure and method for integrating front end SiCr resistors in HiK metal gate technologies

Publication Date: 2014.03.25 TEXAS INSTRUMENTS INC

AI summary

An integrated circuit having a replacement HiK metal gate transistor and a front end SiCr resistor. The SiCr resistor replaces the conventional polysilicon resistor in front end processing and is integrated into the contact module. The first level of metal interconnect is located above the SiCr resistor. First contacts connect to source/drain regions. Second contacts electrically connect the first level of interconnect to either the SiCr resistor or the metal replacement gate.