Category Archives: Chemicals


Wet Processing, including wafer cleaning, is one of the most common yet most critical processing steps in semiconductor manufacturing, since it can have a huge impact on the success of the subsequent process step. Not only does it involve the removal of organic and metal contaminants, but it must leave the surface in a desired state (hydrophilic or hydrophobic, for example), with minimal roughness and minimal surface loss – all on a growing list of different types of materials. In this webcast, experts will identify industry challenges and possible solutions, including a new concept of tailoring chemistries to dissolve very small particles rather than physically removing them.

More than 100 steps in a standard IC manufacturing process flow involve wafer cleaning or surface preparation, which include post-resist strip/ash residue removal, native oxide removal, and even selective etching. Although dry processes continue to evolve and offer unique advantages for some applications, most cleaning/surface prep processes are “wet,” involving the use of a mixture of chemicals such as hydrofluoric; hydrochloric (HCl), sulfuric or phosphoric acid; or hydrogen peroxide, along with copious amounts of deionized water for dilution and rinsing. Wafers are typically processed in a batch immersion or batch spray system or, increasingly, with a single-wafer approach. The trend is toward more dilute chemistries, aided by the use of some form of mechanical energy, such as megasonics or jet-spray processing.

An important distinction in wafer cleaning today is that the main goal is not particle removal, but some other function, such as removing native oxide or photoresist residue removal after strip/ash.

Additional Reading

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Simple wet cleaning improvements can meet new silicon surface preparation criteria

Digital Specialty Chemicals Limited (DSC), a dual bottom line corporation and leading provider of advanced materials to the semiconductor, pharmaceutical, and specialty chemical markets, announced that it has received an equity investment from Intel Capital, Intel Corporation’s global investment organization. The investment will enhance the company’s research and development capabilities and will accelerate manufacturing capacity expansion.

DSC specializes in the manufacture of organophosphorus and organometallic chemistries used in both memory and logic thin film atomic layer deposition (ALD) manufacturing processes at leading semiconductor integrated circuit (IC) fabrication sites worldwide. The company is a leader in the manufacturing and handling of both novel specialty chemicals in large volume, high purity air- sensitive chemicals that require nitrogen and vacuum-operated vessels, using high pressure reactors and multiple distillation techniques.

“Since 1987, we have provided custom and high volume high purity chemicals to the semiconductor, pharmaceutical and specialty chemical markets worldwide. Our people, processes and facilities combine to offer the agility of a small, fine- chemical operation with the capacity of a large supplier,” said Dr. Ravi R. Gukathasan, CEO. “We believe that the continuation of Moore’s Law for semiconductor processing will depend greatly on continued innovation of advanced precursors which provides a growth opportunity for DSC. The funding from Intel Capital will help enable us to construct R&D and manufacturing facilities to meet growing demand for thin film technologies.”

“Materials innovation is critical to enabling new capabilities in semiconductor device design and manufacturing,” said Robert Bruck, corporate vice president and general manager of Global Supply Management at Intel. “We look forward to supporting DSC’s growth including development of new materials technologies for advanced semiconductor manufacturing process technology nodes.”

The 2013 market for semiconductor wet chemicals (acids, bases and solvents) totaled $1.03B, up six percent over 2012, according to a new report from Techcet Group, “Wet Chemicals for Semiconductor Device Processing 2014, A Techcet Group Critical Materials Report.” The 2014 outlook is for eight percent additional growth to $1.11B. The semiconductor wet chemicals market is expected to grow to $1.36B by 2018, according to Techcet’s forecast. Current growth in wet chemicals revenue tracks the increase in wafer starts and further boosted by price increases driven by higher raw materials costs.

As <32nm nodes move toward volume production, there is a continuing trend toward the use of more dilute chemistries and smaller chemical volumes per process step. Overall process cost reduction and a smaller environmental footprint combine to drive this trend. The continuing shrinkage of device features is also driving the reinvestigation of alternative process technologies such as supercritical CO2 all plasma processing, and UV-ozone cleaning.

The global market is distributed among seven major players with five percent share or greater, led by BASF and Kanto in the first tier. There are, however, vast differences in market leadership by region, with BASF leading in Europe, Taiwan and China, and Kanto leading in Singapore and Japan. KMG continues to expand its US market share dominance with its acquisition of OM Group’s Ultra Pure Chemicals business in June, 2013.

The semiconductor wet chemical industry is vulnerable to several situations playing out in the general chemical industry as well as international politics. Semiconductor-grade nitric acid supplies were disrupted by a May 2012 explosion at El Dorado Chemical Company, and are not expected to fully recover until mid-2015. US shale oil production is providing some price escala- tion relief from Middle East petroleum supplies, providing relief in solvents and polyethylene products. New mining activity for phosphor and fluorspar around the world is starting to reduce dependence on China, providing some relief for hydrofluoric and phosphoric acid supplies.

In addition to market analysis, technical trends, critical supply chain issues and EH&S activities, the report includes profiles and updates for thirteen major chemical suppliers to the global semiconductor industry.

Techcet Group, LLC specializes in technical trend analysis and market analysis for the semiconductor, silicon, PV and related electronics industries. The company has been responsible for producing the International Sematech Critical Material Reports since 2001.

July 6, 2011 — Avantor Performance Materials will launch the first in its new J.T.Baker SLCT Series of selective etch surface treatment chemistries, SLCT 128 sigma etchant, at SEMICON West 2011.

J.T.Baker SLCT 128 sigma etchant simultaneously cleans and selectively etches the wafer substrate in poly-gate architectures, creating a cavity for strain engineered gate structures. No pre-implant operations are required to tailor the initial etching. Highly controlled etch is paired with post-etch residue removal and pre-cleaning. The resultant clear, well-defined faceted sigma shape for epitaxy suits advanced nodes, and users may cut out an additional rinse after the process. Plasma pre-etching can be eliminated or reduced in some operations.

The self-cleaning etch chemistry can be used in front end of line (FEOL) wafer fab on strained silicon channels where silicon germanium (SiGe) and silicon nitride (SiN) induce strain on the silicon lattice under the gate region; FinFET structures where the semiconductor material is vertical rather than horizontal; and other advanced wafer processes.

The etchant was created through a joint development agreement between Avantor and SACHEM Inc., which covers specialty surface preparation and removal chemistries for thin-film wafer stacks. Avantor applied photoresist/residue removal technologies, while SACHEM engineered bulk etchants and surface prep aspects. Under the agreements, the companies established a global applications team supported by Avantor’s advanced wafer processing equipment.

Combining the companies’ core strengths in selective etch products enables better semiconductor manufacturing, said John Bubel, director of marketing, electronic materials, at Avantor, adding that the partnership smartly boosts investment in research and development. Tom Mooney, president of SACHEM Asia, added that the partnership is targeting emerging sub-22nm nodes, cutting down on process materials consumption and steps.

Avantor and SACHEM are developing other selective etch and targeted layer removal solutions with leading semiconductor manufacturers in Asia and the Americas.

Avantor plans to expand the SLCT Series with additional selective etch products in the near future, targeting selectivity to metal oxides and integration stacks common in advanced memory chip manufacturing.

To learn more about SLCT 128 sigma etchant and other selective etch products in development, visit Avantor booth 1607 at SEMICON West, July 12-14 at the Moscone Center in San Francisco, CA.

Avantor Performance Materials (formerly Mallinckrodt Baker, Inc.) manufactures and markets high-performance chemistries and materials. Avantor makes products used in the manufacturing of semiconductors, photovoltaic cells and flat panel displays (FPD). For additional information, visit

SACHEM Inc. delivers highly pure, precise and innovative chemical solutions designed to solve the most demanding and challenging applications. Learn more at

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