Semiconductor Substrate Oxide Removal via Silane-Halogen Gas Chemistry

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Solution Overview

Problem

Conventional methods for removing natural oxide films from semiconductor substrates require high-temperature hydrogen annealing, which causes thermal damage and increases the thermal budget, necessitating a low-temperature alternative to prevent substrate damage and contamination.

Innovation Solution

A manufacturing method involving a substrate processing apparatus that uses silane-based, halogen-based, and hydrogen gases to remove natural oxide films and contaminants at low temperatures, with pre-processing steps that include temperature increase to stabilize the substrate surface before epitaxial film growth.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If high-temperature hydrogen annealing is used to remove natural oxide films, then the oxide film removal is effective, but thermal damage to substrate elements increases and thermal budget increases

Engineering Contradiction:

Improveoxide film removal qualityVSAvoidthermal damage to substrate elements

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent changes the temperature parameter from high temperature (conventional annealing) to low temperature processing, and changes the chemical environment from hydrogen atmosphere to silane-based gas atmosphere, achieving oxide film removal without thermal damage

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces the thermal mechanism (heat-driven annealing) with a chemical mechanism (silane-based gas reaction), substituting thermal energy with chemical energy to remove oxide films at low temperatures

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If high-temperature hydrogen annealing is used to remove natural oxide films, then the oxide film removal is effective, but the thermal budget increases

Engineering Contradiction:

Improveoxide film removal qualityVSAvoidthermal budget

Core Design Contradiction:

Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The patent dramatically reduces the temperature parameter from high temperature annealing to low temperature processing (below 450°C), and uses silane-based gas to enable chemical removal of oxide films, thereby reducing thermal budget while maintaining effective oxide film removal

Inventive Principle:

Principle #35Parameter changes

3Quantity of substance

If evacuation is performed in the processing furnace anterior chamber, then oxygen and moisture are removed, but contamination on substrate surface due to organic matter from boat rotation mechanism part and O-ring part occurs

Engineering Contradiction:

Improveoxygen and moisture removalVSAvoidorganic matter contamination

Core Design Contradiction:

Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The patent introduces silane-based gas as an intermediary substance that reacts with and removes organic matter contaminants during the processing, serving as a mediator between the evacuation process and the substrate surface cleaning

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical evacuation process (which causes organic matter contamination) with a chemical process using silane-based gas that actively cleans the substrate surface by reacting with and removing organic contaminants

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

Effectively removes natural oxide films and contaminants at low temperatures, maintaining substrate integrity and achieving high-quality epitaxial film growth with reduced thermal stress and contamination risks.

Implementation Method 1

supplying at least silane-based gas, halogen-based gas, and hydrogen gas to the inside of the processing chamber, thereby removing at least a natural oxide film or a contaminated matter that exists on a surface of the silicon surface

Methodology Applied

Scientific EffectChemical reaction: Chemical Bonding

Implementation Method 2

heating an inside of the processing chamber

Methodology Applied

Scientific EffectHeating: Heating

Implementation Method 3

supplying gas containing at least silicon to the inside of the processing chamber, and making the epitaxial film further grow on the epitaxial film

Methodology Applied

Scientific EffectChemical vapor deposition: Chemical Vapour Deposition

Data Source

PatentUS8123858B2Manufacturing method of semiconductor device and substrate processing apparatus

Publication Date: 2012.02.28 KOKUSAI DENKI KK

AI summary

To provide a manufacturing method of a semiconductor device, comprising: loading a substrate, with a silicon surface exposed at a part of the substrate, into a processing chamber; heating an inside of said processing chamber; performing pre-processing of supplying at least silane-based gas, halogen-based gas, and hydrogen gas into said processing chamber, removing at least a natural oxide film or a contaminated matter that exist on a surface of said silicon surface, and growing an epitaxial film on said silicon surface; and supplying gas containing at least silicon into said processing chamber after said pre-processing, and further growing the epitaxial film on said epitaxial film.