Substrate Holder with Light Shielding for Back Surface Cleaning

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Solution Overview

Problem

Existing substrate processing technologies face challenges in effectively removing organic substances from the back surface of semiconductor wafers without damaging the front surface, as they often result in the infiltration of light and ozone gas, which can harm the wafer's front-side films.

Innovation Solution

A substrate processing apparatus is designed with a light irradiator and a light shielding member to irradiate the back surface of the wafer with ultraviolet light, while preventing light and ozone gas from reaching the front surface, using a holding position changing mechanism to ensure thorough removal of the organic substance across the entire back surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the back surface of the wafer is irradiated with ultraviolet light to remove organic substances, then the organic substance removal effectiveness is improved, but light and ozone gas may infiltrate and damage the front-side films

Engineering Contradiction:

Improveorganic substance removal effectivenessVSAvoidlight and ozone gas infiltration

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The wafer processing is segmented into two separate irradiation steps: first irradiating the back surface to remove organic substances, then flipping the wafer to irradiate the front surface. This segmentation prevents light and ozone gas from damaging front-side films during back surface treatment, while still achieving effective organic substance removal on both surfaces.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The back surface irradiation is performed as a preliminary action before front surface processing. By removing organic substances from the back surface first, then flipping the wafer for front surface irradiation, the system prepares the wafer in a state that prevents harmful infiltration during subsequent processing steps.

Inventive Principle:

Principle #10Preliminary action

2Manufacturing precision

If the entire back surface is irradiated with light, then the organic substance removal coverage is improved, but the processing time increases

Engineering Contradiction:

Improveorganic substance removal coverageVSAvoidprocessing time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The irradiation process maintains continuous useful action by immediately flipping the wafer after back surface treatment and proceeding to front surface irradiation without interruption. This continuous workflow ensures complete coverage of the entire wafer surface while minimizing idle time and maximizing processing efficiency.

Inventive Principle:

Principle #20Continuity of useful action

3Object-affected harmful factors

If a light shielding member is added to prevent light infiltration, then the protection of front-side films is improved, but the device complexity increases

Engineering Contradiction:

Improvefront-side film protectionVSAvoidapparatus structure

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

Instead of adding complex light shielding members to prevent infiltration, the system inverts the approach by flipping the wafer itself. This simple mechanical inversion naturally prevents light and ozone gas from reaching the front surface during back surface irradiation, achieving protection without increasing device complexity.

Inventive Principle:

Principle #13The other way round (Inversion)

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

The apparatus effectively removes organic substances from the back surface of semiconductor wafers without damaging the front-side films, ensuring precise and efficient processing by preventing the infiltration of light and ozone gas.

Implementation Method 1

a light irradiator configured to irradiate the back surface with light so as to remove an organic substance on the back surface of the substrate

Methodology Applied

Scientific EffectPhoto-oxidation: Photo-oxidation

Data Source

PatentUS20230197475A1Substrate processing apparatus, substrate processing method and storage medium

Publication Date: 2023.06.22 TOKYO ELECTRON LTD

AI summary

A substrate processing apparatus includes: a substrate holder configured to hold a substrate while being locally superimposed on a back surface of the substrate; a light irradiator configured to irradiate the back surface with light so as to remove an organic substance on the back surface of the substrate; a light shielding member provided at a back side of the substrate while being spaced apart from the back surface so as to prevent the light from being supplied to a front surface of the substrate; and a holding position changing mechanism configured to change a holding position by the substrate holder on the back surface of the substrate so as to irradiate the entire back surface of the substrate with the light.