Rotating Substrate Etching with Post-Oxidation Protection

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Solution Overview

Problem

Batch-type substrate processing apparatuses face challenges in precisely adjusting etching depths due to film thickness differences, leading to product defects as oxide films are inadvertently etched, exposing polysilicon, and subsequent cleaning processes further damage the substrate.

Innovation Solution

A substrate processing apparatus and method involving a rotor for rotating substrates, a first processing liquid for etching, and a second processing liquid for oxidation, where the second liquid is applied post-etching to form an oxide film, protecting exposed areas and preventing polysilicon exposure during cleaning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If batch-type substrate processing apparatus is used to process multiple substrates at once, then productivity is improved, but manufacturing precision deteriorates due to inability to precisely adjust etching depth for each substrate

Engineering Contradiction:

Improveprocessing throughputVSAvoidetching depth control

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent divides the processing into separate stages: first etching the nitride film to expose the oxide film, then performing oxidation to form a new oxide layer, and finally etching the oxide film. This segmentation allows precise control of each step while maintaining batch processing capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary oxidation before the final oxide film etching step. By forming an oxide layer on the exposed polysilicon surface before cleaning, it prevents polysilicon exposure during subsequent cleaning processes, thereby improving manufacturing precision.

Inventive Principle:

Principle #10Preliminary action

2Manufacturing precision

If phosphoric acid processing liquid is used to etch nitride film, then etching capability is improved, but harmful factors increase due to oxide film etching and polysilicon exposure

Engineering Contradiction:

Improvenitride film etchingVSAvoidoxide film removal and polysilicon exposure

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent performs preliminary oxidation after nitride film etching to form an oxide layer on the exposed polysilicon surface before cleaning. This preliminary protective action prevents harmful polysilicon exposure during subsequent cleaning processes while maintaining effective nitride film etching.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent converts the harmful effect of oxide film removal during etching into a beneficial intermediate state. The exposed oxide film surface is immediately oxidized to form a protective layer, turning the harmful exposure into a controlled intermediate step that enables precise subsequent processing.

Inventive Principle:

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

3Reliability

If cleaning is performed with hot de-ionized water or APM processing liquid after etching, then cleanliness is improved, but manufacturing precision deteriorates due to polysilicon etching

Engineering Contradiction:

Improvecleaning effectivenessVSAvoidpolysilicon integrity

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent performs preliminary oxidation before cleaning to form an oxide layer on the polysilicon surface. This preliminary protective oxide layer prevents polysilicon etching during the subsequent cleaning process with hot de-ionized water or APM processing liquid, thereby maintaining manufacturing precision while ensuring effective cleaning.

Inventive Principle:

Principle #10Preliminary action

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 effectively suppresses product defects by forming a protective oxide film post-etching, reducing exposure of polysilicon during cleaning and maintaining the integrity of the target film, thereby enhancing processing precision and reducing defects.

Implementation Method 1

a first processing liquid supply unit that supplies a first processing liquid for etching to a processing target surface of the substrate that is being rotated by the rotor, thereby etching the processing target surface of the substrate

Methodology Applied

Scientific EffectEtching: Chemical Bonding

Implementation Method 2

a second processing liquid supply unit that supplies a second processing liquid for oxidation to the processing target surface of the substrate that is being rotated by the rotor, thereby forming an oxide film

Methodology Applied

Scientific EffectOxidation: Oxidation

Data Source

PatentUS20240234173A1Substrate processing apparatus and substrate processing method

Publication Date: 2024.07.11 SHIBAURA MECHATRONICS CORP

AI summary

According to one embodiment of the present disclosure, a substrate processing apparatus includes a rotor that holds and rotates a substrate, a first processing liquid supply unit that supplies a first processing liquid for etching to a processing target surface of the substrate that is being rotated by the rotor, thereby etching the processing target surface of the substrate, and a second processing liquid supply unit that supplies a second processing liquid for oxidation to the processing target surface of the substrate that is being rotated by the rotor, thereby forming an oxide film, consecutively to the etching by the supplying of the first processing liquid.