Ion Source Gas Composition for Semiconductor Implantation

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Solution Overview

Problem

Existing ion implant processes are inadequate for scaled-down semiconductor devices as they lead to contamination and reduced system lifetime due to the formation of metal oxides, which affects the performance and integration of circuits.

Innovation Solution

The use of carbon monoxide as a dopant gas and a mixture of xenon and hydrogen as a diluent gas in an ion source, which reduces the formation of oxygen ions and metal oxides, thereby minimizing contamination and extending the system's lifetime by generating high-purity carbon ions for semiconductor substrate implantation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If existing ion implant processes are used for scaled-down semiconductor devices, then device miniaturization is achieved, but contamination and metal oxide formation increase, reducing system lifetime

Engineering Contradiction:

Improvedevice sizeVSAvoidsystem lifetime

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The patent changes the chemical composition parameters of the gas environment in the ion source by introducing a hydrogen-containing gas component. This parameter change modifies the plasma chemistry to suppress metal oxide formation, thereby extending system lifetime while maintaining compatibility with scaled-down device dimensions

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent converts the potentially harmful effect of metal oxide formation into a beneficial outcome by using hydrogen-containing gas to actively suppress oxide formation. The hydrogen reacts with or prevents metal oxide formation, transforming the contamination problem into a solution that extends system lifetime

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Productivity

If existing ion implant processes are used, then ion implantation is performed, but metal oxide formation causes contamination, reducing ion extraction quality

Engineering Contradiction:

Improveion implantation throughputVSAvoidion extraction quality

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent creates a hydrogen-rich atmospheric environment in the ion source that acts as a protective atmosphere, preventing metal oxide formation. This inert-like environment (relative to oxygen reactions) maintains high ion extraction quality by eliminating contamination sources while allowing continuous high-productivity operation

Inventive Principle:

Principle #39Inert atmosphere (Inert environment)

3Quantity of substance

If traditional dopant gases are used in ion source, then ion generation occurs, but oxygen ions are formed, leading to metal oxide contamination

Engineering Contradiction:

Improveion generation rateVSAvoidmetal oxide contamination

Core Design Contradiction:

Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The patent introduces hydrogen-containing gas as an intermediary substance that mediates between the metal components and oxygen. The hydrogen acts as a protective intermediary that preferentially reacts with or prevents oxygen from forming metal oxides, thereby maintaining high ion generation rates while eliminating contamination

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the gas composition parameters by adding hydrogen-containing components to the dopant gas mixture. This parameter modification alters the plasma chemistry to suppress oxygen ion formation and metal oxide generation, maintaining productivity while eliminating harmful contamination

Inventive Principle:

Principle #35Parameter changes

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 enhances the productivity and longevity of the ion implantation system by reducing metal oxide formation, leading to improved ion extraction and implantation quality, and increased beam current, thus supporting higher integration and performance in semiconductor devices.

Implementation Method 1

Plasma is generated from the dopant gas and the diluent gas in the ion source arc chamber

Methodology Applied

Scientific EffectPlasma generation: Plasma

Implementation Method 2

A dopant gas and a diluent gas are introduced in an ion source arc chamber. Plasma is generated from the dopant gas and the diluent gas in the ion source arc chamber

Methodology Applied

Scientific EffectIonization: Ionisation

Implementation Method 3

A filament is configured to heat the cathode

Methodology Applied

Scientific EffectResistive heating: Joule Heating

Implementation Method 4

The electrons emitted by the cathode are accelerated

Methodology Applied

Scientific EffectThermionic emission: Thermionic Emission

Data Source

PatentUS9922800B2System and method for generating ions in an ion source

Publication Date: 2018.03.20 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

Embodiments of a method for generating ions in an ion source are provided. The method for generating ions in an ion source includes introducing a dopant gas and a diluent gas into an ion source arc chamber. The method for generating ions in an ion source further includes generating plasma in the ion source arc chamber based on the dopant gas and the diluent gas. In addition, the dopant gas includes carbon monoxide, and the diluent gas includes xenon and hydrogen.