semiconductor wet chemical processes

Inhaltsverzeichnis

The Importance of Wet Chemical Processes in the Semiconductor Industry

The semiconductor industry is one of the most technologically demanding manufacturing sectors worldwide.

Modern microchips consist of extremely fine structured layers. Even the smallest contamination can affect their electrical performance and reliability.

Wet chemical processes are therefore a fundamental part of semiconductor wafer manufacturing.

They are used for:

  • wafer cleaning
  • removal of organic residues
  • removal of metallic contamination
  • oxide removal
  • chemical etching
  • surface activation
  • preparation for subsequent process steps

The equipment used for these processes is known as Wet Benches.

 

Why are Wet Processes Critical in Wafer Manufacturing?

A semiconductor wafer passes through numerous process steps during manufacturing.

During these processes, unavoidable residues are generated:

  • particles
  • metals
  • organic contamination
  • oxide layers
  • photoresist residues

These contaminants must be removed in a controlled manner.

Even the smallest defects can lead to:

  • functional failures
  • reduced yield
  • quality issues

 

Wafer Manufacturing Process Flow

A typical semiconductor production process includes numerous wet chemical process steps.

Simplified process sequence:

  1. Silicon wafer
  2. Cleaning
  3. Oxide removal
  4. Coating
  5. Photolithography
  6. Development
  7. Etching
  8. Cleaning
  9. Repetition of multiple process cycles

 

Wafer Cleaning

Cleaning of Silicon Wafers

Wafer cleaning is one of the most important wet chemical processes in semiconductor manufacturing.

The goal is to achieve a:

  • particle-free surface
  • metal-free surface
  • chemically defined surface

 

Which Contaminants Must Be Removed?

 

Particles

Particles can:

  • damage structures
  • create defects
  • cause electrical failures

Removal methods include:

  • SC1 cleaning
  • megasonic cleaning
  • ultrasonic cleaning

 

Organic Residues

Sources include:

  • photoresist
  • polymers
  • process chemicals

Removal methods:

  • solvent cleaning
  • oxidative cleaning

 

Metallic Contamination

Examples:

  • iron
  • copper
  • nickel

Removal method:

  • SC2 cleaning

 

RCA Cleaning in Semiconductor Manufacturing

Standardized Wafer Cleaning Process

RCA cleaning is one of the most established cleaning procedures for silicon wafers.

It consists of:

  1. SC1 cleaning
  2. rinsing
  3. SC2 cleaning
  4. final cleaning

 

SC1 Cleaning for Semiconductor Wafers

Removal of Particles and Organic Residues

SC1 typically uses:

  • ammonium hydroxide
  • hydrogen peroxide
  • ultrapure water

Purpose:

  • particle removal
  • organic contamination removal
  • surface activation

 

SC2 Cleaning for Semiconductor Wafers

Removal of Metallic Contamination

SC2 cleaning uses:

  • hydrochloric acid
  • hydrogen peroxide
  • ultrapure water

Purpose:

  • removal of metal ions
  • improvement of surface cleanliness

 

HF Dip in Semiconductor Manufacturing

Removal of the Native Oxide Layer

Silicon automatically forms a thin oxide layer when exposed to air.

This native oxide layer can influence subsequent process steps.

HF Dip removes:

  • silicon oxide
  • native oxide layers

Typical applications:

  • before coating processes
  • before epitaxial processes
  • before contact formation

 

Megasonic Cleaning for Semiconductor Wafers

Particle Removal for Sensitive Structures

Megasonic cleaning uses high-frequency acoustic waves to remove contaminants from wafer surfaces.

Advantages:

  • removal of extremely small particles
  • low mechanical stress
  • suitable for sensitive wafer structures

Typical applications:

  • advanced semiconductor generations
  • MEMS manufacturing
  • sensor technologies

 

Ultrasonic Cleaning in Semiconductor Manufacturing

Ultrasonic cleaning uses cavitation effects to support the cleaning process.

Suitable for:

  • robust components
  • development processes
  • special cleaning applications

For highly sensitive wafer structures, megasonic cleaning is often preferred.

 

Wet Chemical Etching of Wafers

Material Removal Through Chemical Reactions

Etching processes selectively remove material layers from wafer surfaces.

Typical applications:

  • oxide removal
  • silicon structuring
  • layer removal

 

HF Etching of Silicon Structures

HF is used for the removal of:

  • silicon oxide
  • glass structures
  • oxide-based layers

 

KOH Etching of Silicon

KOH enables anisotropic silicon etching.

Applications:

  • MEMS
  • sensors
  • micromechanical structures

 

Solvent-Based Processes in Semiconductor Manufacturing

Removal of Organic Materials

Solvent-based processes are especially used for:

  • photoresist removal
  • polymer removal
  • organic residue removal

 

Photoresist Removal

Removal of Photoresist Layers

Photoresists are essential materials for transferring microscopic patterns during semiconductor manufacturing.

After processing, the photoresist layer must be removed.

Methods include:

  • solvent stripping
  • chemical stripping
  • plasma processes

 

Typical Wet Bench Processes in Semiconductor Manufacturing

A modern semiconductor Wet Bench system can integrate various processes:

  • RCA Cleaning
  • SC1 Cleaning
  • SC2 Cleaning
  • HF Dip
  • Megasonic Cleaning
  • solvent-based processes
  • rinsing processes
  • drying processes

 

Requirements for Semiconductor Wet Benches

Semiconductor manufacturing requires the highest level of process control and equipment reliability.

Important requirements include:

 

Cleanliness

Critical factors:

  • low particle contamination
  • suitable high-purity materials
  • controlled process media

 

Process Stability

Precise control of:

  • temperature
  • chemical concentration
  • process time
  • flow rate

 

Automation

Modern Wet Bench systems enable:

  • reproducible process sequences
  • automated wafer handling
  • continuous process monitoring

 

Advanced Wet Bench Technology for Semiconductor Applications

Modern semiconductor manufacturing requires customized process equipment that combines chemical precision, contamination control, and automation.

A high-performance Wet Bench system enables:

  • stable chemical processes
  • repeatable wafer cleaning results
  • controlled etching processes
  • safe handling of aggressive chemicals
  • integration into semiconductor production environments

 

Process Control in Semiconductor Wet Processing

The performance of a Wet Bench system depends on accurate control of critical process parameters:

  • chemical concentration
  • temperature stability
  • process timing
  • fluid flow control
  • rinsing efficiency
  • drying performance

 

Materials and Construction Requirements

Semiconductor Wet Bench systems require carefully selected materials to ensure compatibility with demanding process chemicals.

Important design factors include:

  • chemical resistance
  • low particle generation
  • cleanroom compatibility
  • long-term process stability

 

PaceTec Expertise

PaceTec develops customized Wet Bench systems for demanding semiconductor manufacturing processes.

Our solutions support:

  • wafer cleaning
  • RCA cleaning processes
  • SC1 / SC2 cleaning
  • HF Dip processes
  • Megasonic Cleaning
  • wet chemical etching processes
  • solvent-based cleaning processes

 

By combining:

Process Knowledge + Chemical Expertise + Equipment Engineering

PaceTec creates reliable and reproducible wet processing solutions for advanced semiconductor manufacturing.

 

Customized Semiconductor Wet Bench Systems by PaceTec

The increasing complexity of semiconductor manufacturing requires highly precise and reliable wet chemical process equipment.

PaceTec develops customized Wet Bench systems designed for advanced semiconductor applications where highest demands are placed on:

  • process accuracy
  • surface cleanliness
  • chemical compatibility
  • process repeatability
  • production reliability

 

Integrated Solutions for Semiconductor Wet Processing

A successful semiconductor wet process requires the interaction of:

Chemistry + Process Control + Material Selection + Equipment Engineering

 

PaceTec supports customers in developing application-specific solutions for:

  • silicon wafer cleaning
  • advanced semiconductor manufacturing
  • MEMS processing
  • microelectronics applications
  • surface preparation processes
  • chemical etching applications

 

Reliable Wet Chemical Equipment for Semiconductor Manufacturing

PaceTec Wet Bench systems are engineered for stable and reproducible production processes.

Key capabilities include:

  • controlled chemical supply systems
  • automated process sequences
  • precise temperature management
  • high-purity process handling
  • cleanroom-compatible equipment design

 

Wet Bench Technology for Future Semiconductor Requirements

As semiconductor structures become smaller and process requirements become more demanding, reliable wet processing technology becomes increasingly important.

Customized Wet Bench systems from PaceTec provide the foundation for:

  • high process stability
  • improved manufacturing yield
  • consistent wafer quality
  • advanced semiconductor production

 

PaceTec – Your Partner for Customized Wet Processing Systems

PaceTec combines decades of engineering expertise with deep knowledge of wet chemical processes.

From individual process requirements to complete Wet Bench solutions, PaceTec delivers customized systems for demanding high-tech industries.

 

Process Expertise + Chemical Understanding + Precision Engineering

 

for reliable wet processing solutions in semiconductor manufacturing, microelectronics, MEMS, and advanced industrial applications.

 

Table of content

Frequently asked question

FAQ's

Wafer cleaning is one of the most critical process steps in the manufacturing of modern semiconductor devices.

During chip production, various types of contamination inevitably occur, such as:

  • particles
  • metal ions
  • organic residues
  • photoresist residues
  • oxide layers

Even the smallest contaminants can lead to defects on the wafer and reduce manufacturing yield.

The goal of wafer cleaning is to create a defined, ultra-clean surface for subsequent process steps such as:

  • lithography
  • etching
  • coating
  • deposition

Typical cleaning processes include:

  • RCA cleaning (SC1 / SC2)
  • Piranha cleaning
  • HF dip
  • megasonic cleaning
  • quick dump rinse (QDR)

Modern wet bench systems enable controlled and reproducible wafer cleaning under cleanroom conditions.

In semiconductor manufacturing, various cleaning processes are used because different types of contaminants must be removed in a targeted manner.

 

RCA Reinigung

Das RCA-Verfahren ist ein Standardverfahren für Siliziumwafer.

 

SC1 Reinigung

Entfernt:

  • Partikel
  • organische Rückstände

 

SC2 Reinigung

Entfernt:

  • metallische Verunreinigungen
  • Ionen von Metallen wie Eisen oder Kupfer

 

Piranha-Reinigung

Entfernt:

  • hartnäckige organische Rückstände
  • Fotolackreste

durch eine stark oxidierende Chemie aus:

  • Schwefelsäure (H₂SO₄)
  • Wasserstoffperoxid (H₂O₂)

 

HF-Dip

Entfernt:

  • native Oxidschichten
  • Siliziumoxid

und erzeugt eine definierte Siliziumoberfläche.

Die Auswahl des Reinigungsverfahrens hängt von Prozessschritt, Material und Reinheitsanforderung ab.

In wet chemical etching, material is selectively removed through chemical reactions.

The main difference lies in the direction of material removal.

Isotropic Etching

The material is removed at a similar rate in all directions.

Characteristics:

  • rounded or undercut structures
  • high etch rate
  • simple process control

Typical applications:

  • oxide removal
  • cleaning processes

Anisotropic Etching

Material removal depends on the crystal structure of the material.

Typical example:

  • KOH etching of silicon

Applications:

  • MEMS structures
  • sensors
  • micromechanical components

The choice between isotropic and anisotropic etching depends on the desired structure and the specific application.

The surface condition of a wafer has a major influence on the quality of subsequent manufacturing processes.

Through wet chemical surface treatment, the following properties can be specifically modified:

  • surface cleanliness
  • oxide layers
  • surface roughness
  • wettability
  • chemical properties

Typical processes include:

  • oxide removal using HF dip
  • cleaning prior to coating processes
  • surface activation before deposition processes

A well-defined surface improves, for example:

  • layer adhesion
  • process stability
  • electrical properties

Therefore, surface control is a critical factor in modern semiconductor technologies.

Wet bench systems for semiconductor manufacturing must meet the highest requirements for cleanliness, process control, and safety.

Key requirements include:

Process Control

Monitoring of:

  • temperature
  • chemical concentration
  • process time
  • flow rate
  • conductivity

Cleanliness

Critical factors include:

  • low particle contamination
  • suitable materials of construction
  • controlled media handling

Process Integration

Modern wet bench systems can combine:

  • RCA cleaning
  • Piranha cleaning
  • HF dip
  • megasonic cleaning
  • quick dump rinse (QDR)
  • Marangoni drying

Automation

For industrial manufacturing, the following are used:

  • automated wafer handling
  • recipe control
  • process data acquisition
  • interfaces to manufacturing systems

PaceTec develops customized wet bench systems for high-purity wafer processes and supports the integration of complete process chains from cleaning to drying.

Together, we will develop the ideal solution for your wet chemical applications.

Contact us for more information or personalized consultation.