Wafer Cleaning via Light Irradiation for IPA Residue Removal

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Solution Overview

Problem

In semiconductor device manufacturing, the increasing integration of components leads to pattern leaning issues during wafer cleaning due to residue from isopropyl alcohol (IPA) left after IPA/CO2 substitution processes, which can cause defects in subsequent processes.

Innovation Solution

A wafer cleaning apparatus using light irradiation to effectively remove IPA residue without damaging the wafer, incorporating a light irradiation unit, a wafer processing unit for precise positioning, and a cooling unit, where the light irradiation unit is above the wafer processing unit and cooling unit in a vertical structure, allowing for efficient cleaning and drying processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional cleaning processes are used to remove residue, then cleaning efficiency is improved, but pattern leaning occurs and wafer integrity is compromised

Engineering Contradiction:

Improvecleaning efficiencyVSAvoidpattern leaning

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent replaces conventional mechanical/chemical cleaning methods with a light irradiation system. The light irradiation unit emits light at specific wavelengths to selectively remove organic residue through photodecomposition, eliminating the need for aggressive chemical cleaners that cause pattern leaning while maintaining cleaning effectiveness.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the cleaning mechanism from chemical/physical removal to optical energy-based removal. By controlling light irradiation parameters (wavelength, intensity, duration), the system achieves selective residue removal without affecting the wafer structure or causing pattern distortion, thus resolving the contradiction between cleaning efficiency and manufacturing precision.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If light irradiation energy is increased to improve residue removal, then cleaning efficiency is improved, but wafer damage occurs

Engineering Contradiction:

Improveresidue removal efficiencyVSAvoidwafer damage

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by using light irradiation with specific wavelengths that are selectively absorbed by organic residue but not by the wafer materials. This selective interaction allows high-energy light to remove residue effectively while the wafer remains unaffected, resolving the contradiction between removal efficiency and wafer safety.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent introduces light as an intermediary that mediates between the cleaning objective and wafer protection. The light irradiation unit delivers energy selectively to the residue through optical absorption differences, acting as a safe intermediary that transfers cleaning action without directly contacting or damaging the wafer substrate.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If cooling time is extended to prevent wafer damage, then wafer integrity is improved, but processing time increases

Engineering Contradiction:

Improvewafer integrityVSAvoidprocessing time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by implementing a cooling unit that actively cools the wafer immediately after light irradiation. This preliminary cooling prevents heat accumulation and potential damage before the wafer proceeds to the next processing step, maintaining wafer integrity without requiring extended cooling periods that would slow down production.

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

The apparatus effectively removes IPA residue and prevents defects in subsequent processes by selectively heat-treating the wafer with light irradiation, improving cleaning efficiency and reducing pattern leaning issues while maintaining wafer integrity.

Implementation Method 1

a light irradiation unit configured to irradiate light onto the wafer during the light irradiation

Methodology Applied

Scientific EffectLight irradiation: Light

Implementation Method 2

selectively heat-treating the wafer with light irradiation

Methodology Applied

Scientific EffectPhotothermal heating: Heating

Implementation Method 3

a cooling unit configured to cool the wafer after the light irradiation has been completed

Methodology Applied

Scientific EffectCooling: Cooling

Data Source

PatentUS11527399B2Wafer cleaning apparatus based on light irradiation and wafer cleaning system including the same

Publication Date: 2022.12.13 SAMSUNG ELECTRONICS CO LTD

AI summary

Provided are a wafer cleaning apparatus based on light irradiation capable of effectively cleaning residue on a wafer without damaging the wafer, and a wafer cleaning system including the cleaning apparatus. The wafer cleaning apparatus is configured to clean residue on the wafer by light irradiation and includes: a light irradiation unit configured to irradiate light onto the wafer during the light irradiation; a wafer processing unit configured accommodate the wafer and to control a position of the wafer such that the light is irradiated onto the wafer during the light irradiation; and a cooling unit configured to cool the wafer after the light irradiation has been completed. The light irradiation unit, the wafer processing unit, and the cooling unit are sequentially arranged in a vertical structure with the light irradiation unit above the wafer processing unit and the wafer processing unit above the cooling unit.