Semiconductors: Dependable Atline, Online and Inline Solutions for Your Process Needs

Integrated circuits are the fundamental element of modern electronic goods. In this digital era, smaller, quicker and more powerful processors are in consant demand for many goods and services. The semiconductor industry is mainly responsible for developing various aspects of contemporary society because many services are digitized and interlinked (example, Internet of Things, Big Data and Smart Grids).

Figure 1.

Cleanliness is crucial in the semiconductor fabrication facility, considering the scale of the working surfaces (Nanometers). Top manufacturers have to follow stringent production control procedures, as various forms of contaminants may lead to defects.

One fabrication plant can use up to 15 million liters of ultrapure water each day. Even bacteria must be eliminated, as they have trace elements which can change the electrical properties of the silicon wafer used to build transistors for integrated circuits.

Processing the raw material (Monocrystalline Silicon) into a finished integrated circuit involves different stages. Each stage requires a great deal of attention to guarantee that the quality of the finished product is high. Process optimization through online monitoring of parameters like water quality, metal content in plating baths and acids in etch baths not only saves time but also reduces the production costs considerably. Metrohm Process Analytics offers online process analyzers that are indispensable in any semiconductor plant to run processes closer to strict specifications, enhancing different manufacturing phases and reducing waste.

	FEOL Front End Of Line				BEOL Back End Of Line
SC1 / SC2 clean Ultrapure water quality for wafer preparation TMAH in developer Mixed acid etching bath analysis (MAE) Composition of etching cleaner solution Hydrogen Peroxide in CMP Slurry Sulfuric acid and peroxide mixture in Photoresist Stripping				Hydrogen Peroxide in CMP Slurry TMAH in developer Etching baths (mixed acids) composition Acid copper bath measurements for Damascene Process Heavy metal concentrations in plating baths Organic additive concentrations in plating baths Electroless Cu/Ni and Hypophosphite [H2PO2-]
SUBFAB
• Ultrapure water quality for Chemical Distribution and Dilution • H2O2, pH, temperature and conductivity in Slurry production, blending and distribution • ECP Clean (Acid) for Chemical Delivery • Hydrogen fluoride in Chemical Dilution system • Ammonium in Chemical Dilution system • Chloride [Cl-] in H2SO4 recovery system

Overview of a wide variety of applications sold by Metrohm Process Analytics in different areas within semiconductor plants.

Ultrapure Water Specifications

The most consumed chemical in the manufacture of integrated circuits is actually ultrapure water. Several plants produce ultrapure water on-site as it is required in several areas, right from rinsing after etching steps to the dilution of concentrated chemicals in the subfab. Working efficiency of the ion exchangers upstream can be determined by trace analysis of this ultrapure water. Impurities can lead to uneven etching or uneven plating, which can cost a manufacturer many times more than preventive maintenance to the ion exchanger.

Wastewater from Circuit Production

Compliance with regulatory agencies is necessary, and with more and more stringent guidelines evolving each year it is very important to check wastewater and make sure that the treatment facility is working effectively. Several process analyzers are available from Metrohm Process Analytics which can measure from single to multiple components in waste streams, with customize-built sample preconditioning setups and shelters available for more challenging areas around the plant.

• Dilute metal waste stream analysis
• Concentrated copper waste analysis
• Wastewater monitoring of several components

Metrohm Process Analytics provides different analytical approaches in many different analyzer configurations for any requirement such as ion chromatography, photometry, NIR spectroscopy, titration, and ion-selective measurements. Metrohm’s online process analyzers and custom-built sample preconditioning systems are developed in the Netherlands and maintained by Metrohm’s local service Engineers globally.

Applications

Production Control of Electroplating Baths

The wide-spread methods used for the identification of organic additives in electroplating baths are Cyclic Pulse Voltammetric Stripping Analysis (CPVS) and Cyclic Voltammetric Stripping Analysis (CVS). For various technical coatings, especially in the manufacture of printed circuit boards and semiconductor components, this method is an important part of production control. Online analysis with Metrohm’s ADI 2045VA Process Analyzer removes the need for gradual, repeated laboratory Quality Control, ensuring continuous and interference-free function of the plating baths.

• Precise measurements even in saline conditions
• Accurately measure brighteners, levelers, and suppressors
• Concentrations in mL additive per L bath liquid
• Suitable for tin-lead baths, alkaline zinc baths, tin baths, acidic copper baths, etc.

Process Ion Chromatograph

Fast, In-situ, Non-destructive Analyzes

Using online Near-Infrared Spectroscopy (NIRS), bath composition, the purity of chemicals and other processes can be easily tracked around the clock. Real-time data can be obtained by chemical-free process analysis with NIRS, saving both time and money compared to other analytical methods. Multiplexer choices enable monitoring many baths by the same analyzer, from clear liquids to opaque slurries. NIR can also be used to analyze the surface wafer surface.

• Mixed acid baths
• TMAH in water
• SC1 / SC2
• HF-Dip
• HotPhos (H₃PO₄ in water)

ADI 2045VA Process Analyzer

Multicomponent Determination in a Single Run

Ion chromatography (IC) allows the determination of many primary and secondary components of electroplating baths and traces of impurities in the form of inorganic and organic ions or polar substances with great precision and reliability. A key advantage is that substances that are chemically similar can be determined in parallel in a single analysis with Ion chromatography. Analyte concentrations may range from the ng/L to % limits. Interfering matrix effects can be prevented by integrating the sample delivery with one of Metrohm’s varied Inline Sample Preparation Techniques.

• Impurities in electroplating baths
• Concentrated acids in etching solutions
• Nitrate in nickel baths
• Ion analysis in emulsions and soap-containing rinsing solutions
• Trace analysis in ultrapure water

NIRS XDS Process Analyzer

NIRS Analyzer PRO

This information has been sourced, reviewed and adapted from materials provided by Metrohm AG.

For more information on this source, please visit Metrohm AG.