Semiconductor chemicals

• Wafer Manufacturing Process
• Purity: a must
• Rhodia Product Range to serve the electronic market

Rhodia Electronics & Catalysis is an electronic chemical supplier for Integrated Circuits Manufacturers and proposes various products such as solvents for photoresist and packaging polymers, etching agents, stripper additives and monomers for polymers. To introduce the functionality of our product range, we will review the steps to manufacture a chip.

• Wafer Manufacturing Process

Doping and oxidation
Polysilicon crystals are cut into wafers and polished. In ultra pure form, the controlled addition of minute amount of certain impurities (called dopants) alters the atomic structure and modifies electric behaviour of the semiconductor.
Silicon surface is converted into silicon dioxide by oxidation under oxygen at high temperature. Silicon oxide obtained will form connection behind conductors canals.

Photolithography and Development
A photoresist or light sensitive film is applied by spin coating to the wafer, giving it characteristics similar to photographic paper. This film is irradiated by UV through a mask used to expose selected areas of photoresists which defines areas to be developed and etched. The number of masks applied to make the Integrated Circuits is often considered as a measure of the complexity of the circuit. Developers are either aqueous solutions or organic solvents.

Etching and Stripping
Etching is the process to remove layers of unwanted silicon, silicon dioxide and other materials from a wafer. Wet etching involves the use of acids whereas dry etching uses hot plasma gas. Stripping consists to clean residual resists from surface substrate with organic chemicals.

Diffusion
To built the semiconductor, introduction of dopants into the silicon crystal lattice of the wafer is then implemented to change the electric characteristics of silicon to make it either P (Positive) type silicon or N (Negative) type silicon.

By repeating these steps (Photolithography, Etching, Stripping and Diffusion) over and over again, the components of the circuit are embedded internally in the circuit in a number of semiconductor material.

Planarization
After the different previous steps, a polishing of the wafer is implemented by Chemical Mechanical Planarization (CMP process). This process combines chemical and physical processes: a pad and CMP slurries are applied onto the wafer at high speed.

Packaging
The semiconductor obtained is protected by polymer packaging.

• Purity: a must

Purity is a critical technical issue for all electronic chemicals. Even small traces of impurities left on the semiconductor surface can cause leakage currents or other electronic difficulties that ultimately reduce the performance and reliability of the device.

Thanks to an important industrial know-how, Rhodia Electronics & Catalysis, prepares high purity grades of its well-known products to meet electronic quality standards.

Acids for etching:

Solvents for Photopolymers & Photoresists

« Looking for a solvent ? Think RHODIASOLV™ »

Rhodia offers a range of various solvents under its trademark RHODIASOLV™:

Rhodiasolv™.CPT.XP, ULSI (Cyclopentanone): aprotic solvent, inert, very low toxicity.
Rhodiasolv™.MPE.XP (Anisole): excellent solvent, high boiling point, low toxicity, very easy recycling.
Rhodiasolv™.BTF.XP (Benzenetrifluoride): excellent substitute to chlorinated solvents, polar, low toxicity, high boiling point.
Rhodiasolv™.IAA (Isoamyl Acetate)
Phenetole
Cyclopentanol

Rhodiasolv™ are special high purity grades products dedicated for electronic market with commitment on metal content (less than 5 ppb of metals for most of them).

Corrosion Inhibitors
• Catechol (Flakes)
• Tertiobutyl Catechol (TBC) Flakes
• Tertiobutyl Catechol (TBC) 85% Methanol
• Tertiobutyl Catechol (TBC) 85% Water

Photoresist Monomer
Salicylaldehyde

CMP (Chemical Mechanical Polishing)
• Polishing Opaline SM2
• Polishing Opaline

Raw material for Cerium Ammonium Nitrate (CAN)
• Cerium Hydroxide 90

• Rhodia Product Range to serve the electronic market

Our experience in electronic chemical market, allows us to propose a range of chemical products with potential application and to upgrade them to meet electronic standards.

Solvents: Rhodia offers an alternative range of solvents to conventional used in electronic: TrifluoroEthanol, TrifluoroAnisole, TrifluoroAcetic Acid, DiIsopropylKeton, Benzyl Salicylate, Hexyl Salicylate….

PhotoAcid Generator (PAG): Triflic Acid, Triflic derivates (CF3SO₂)2NLi

Corrosion Inhibitor: Salicylic Acid

Metallization additives: Triflic Acid

Rhodia can also offer its large experience in chemistry to develop new products based on its core competencies in close partnership with its customers.

• Contacts

If you would like more informations, please contact:
ec-electronics@eu.rhodia.com