ATMI and Matheson EPG, Partners in an SDS Gas Source Retrofit Program, Provide Assistance to Improve Safety, Maximize Tool Utilization and Lower Cost.

DANBURY, Conn.--(BUSINESS WIRE)--April 26, 1999--

ATMI, Inc. (Nasdaq: ATMI), today announced a new semiconductor industry-wide SDS(R) Gas Source retrofit program for ion implanters. The retrofit program is a joint effort between ATMI's NovaSource business, end users of Ion Implant equipment and Matheson Electronic Products Group (EPG), the exclusive licensee to market, manufacture and distribute worldwide the SDS products to the implant market.

Under this new program, Matheson is identifying opportunities to offer semiconductor manufacturers an easy, low risk approach to changing from high pressure implant dopant gases to sub-atmospheric SDS(R) Gas Sources. Matheson works with end users to identify an upgrade program that addresses their needs to maximize tool utilization, lower costs, and improve safety. The program provides the end user with information that will assist them in determining the advantages of the upgrade.

Doug Neugold, NovaSource President commented, "With the adoption of SDS Gas Source technology, the industry has seen implanter productivity improve on the order of 10%. In some cases, return on investment is measured in months, and savings in hundreds of thousands of dollars. The savings from using the SDS Gas Source technology in an ion implanter can contribute to our customers' strength in fighting the current downturn."

Rich Outcault, manager of Upgrade and Refurbishment Programs at Varian, a leading global supplier of Ion Implant equipment said, " In the current difficult market condition, we are always looking to expand our efforts to improve our customers' productivity and yield, while reducing their costs. Offering a manufacturer-approved SDS Gas Source retrofit program is consistent with these objectives."

Mike Pfarr, VP of Marketing at Matheson EPG commented, "Since we began selling the SDS Gas Source to the ion implantation market, more than 80% of new implanters have shipped `SDS ready' and are using SDS products. This retrofit program is the next step in our commitment to improve our customers' manufacturing productivity, by assisting them in making upgrade decisions regarding their existing implanters which were not originally configured for SDS Gas Sources."

ATMI provides products and services for semiconductor device manufacture through its Materials and Technologies units. ATMI Materials includes ADCS thin film materials and delivery systems, NovaSource, which manages the development and marketing of SAGE(TM)(Sub-Atmospheric Gas Enhanced) gas delivery systems, and NOW high-purity materials packaging systems. ATMI Technologies include EcoSys environmental equipment, Epitronics thin film deposition services, Emosyn smart card solutions, and other ATMI ventures.

Headquartered in San Jose, CA, Matheson Electronic Products Group is a global leader in the production of specialty gases and delivery equipment. In addition to the SDS Safe Delivery Source products, Matheson EPG core competencies also include ULTRA-LINE high purity process gases, Semi-Gas Systems brand of gas handling equipment, Nanochem brand of purification systems, customer technical services, systems engineering and site management services. It's parent company, Nippon Sanso Corporation (NSC), is the world's largest supplier of gases and equipment to the semiconductor industry.

Statements which are not historical information are forward looking, and involve risks and uncertainties, including, but not limited to: changes in semiconductor industry growth or ATMI's markets; competition, problems, or delays developing and commercializing new products, and other factors discussed in ATMI's filings with the Securities and Exchange Commission.