SiO2 Layer Hydrogen Passivation for Low-Temperature NBTI Reliability

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Solution Overview

Problem

Bias temperature instability (BTI) in SiO2 layers of metal-oxide-semiconductor structures is a concern, particularly negative BTI (NBTI), which affects the reliability of semiconductor devices and is exacerbated by thermal-budget limitations in advanced technologies.

Innovation Solution

Exposure of SiO2 layers to atomic hydrogen at relatively low temperatures (100-300°C) effectively passivates electrically active defects such as hydroxyl-E' and hydrogen bridge defects, reducing charge trapping and improving BTI, regardless of the formation temperature or method of the SiO2 layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high-temperature fabrication steps (e.g., rapid thermal oxidation at 900+°C, reliability anneal at >800°C) are used to minimize hole trap density in SiO2, then NBTI reliability is improved, but thermal-budget limitations in advanced technologies prevent their use

Engineering Contradiction:

ImproveNBTI reliabilityVSAvoidfabrication temperature

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The patent changes the treatment method from thermal (high-temperature oxidation and annealing) to chemical (hydrogen plasma treatment at low temperature). This parameter change allows achieving low hole trap density at temperatures compatible with advanced technology thermal budgets, resolving the contradiction between reliability improvement and temperature constraints

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces the thermal field (heat treatment) with a chemical field (hydrogen plasma treatment). Instead of using high-temperature thermal processes to reduce hole traps, the invention uses low-temperature hydrogen plasma to passivate defects, substituting one physical field for another to overcome the thermal-budget limitation

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 significantly reduces the trapped charge sheet density and improves NBTI reliability, matching or exceeding the performance of SiO2 layers formed at higher temperatures, while being compatible with low thermal budgets, thus enhancing the stability and performance of semiconductor devices.

Implementation Method 1

Exposure of SiO2 layers to atomic hydrogen at relatively low temperatures (100-300°C) effectively passivates electrically active defects such as hydroxyl-E' and hydrogen bridge defects

Methodology Applied

Scientific EffectPassivation:

Implementation Method 2

exposing the SiO2 layer to the source/drain doping activation anneal at 1000+°C... applying rapid thermal anneals in a so-called 'reliability anneal' (e.g., >800°C for 1-2 s)... Exposure of SiO2 layers to atomic hydrogen

Methodology Applied

Scientific EffectHydrogenation: Hydrogenation

Data Source

PatentUS12009204B2Bias temperature instability of SiO<sub>2 </sub>layers

Publication Date: 2024.06.11 INTERUNIVERSITAIR MICRO ELECTRONICS CENT (IMEC VZW)

AI summary

A method for improving a bias temperature instability of a SiO2 layer comprises exposing the SiO2 layer to atomic hydrogen.