For more information, contact:

Jim Donaldson
Advanced Energy Industries, Inc.
Marna Shillman
Advanced Energy Industries, Inc.

Two Patents for RF Plasma Measurement and Control
Fort Collins, Colorado (October 8, 1999) – Advanced Energy Industries, Inc. (Nasdaq NM: AEIS) has been granted two United States patents for RF plasma measurement and control technology.

Patent 5,939,886 covers techniques for plasma monitoring and control of radio frequency (RF) power, including monitoring of RF voltage, current, phase angle, and full-load impedance. Without these techniques, measurements of process and plasma parameters are difficult to accomplish. This patent includes sensing RF quantities at the input of the processing environment, which permits the inference of important process and plasma parameters. Thus, the techniques covered by this patent overcome the problems associated with previous techniques, which measure RF power at the generator output.

Patent 5,576,629 builds on the techniques covered by patent 5,939,886 and includes technology for controlling the voltage, current, and phase angle of the RF power directed to the plasma-producing gas within a pre-determined region of variability.

With the issuance of these two patents, AE now has broad patent protection for much of its RF plasma measurement and control technology.

Advanced Energy is a worldwide leader in the development and marketing of power conversion and control system solutions, ion-beam sources, and plasma abatement systems. Customers throughout the world use Advanced Energy’s products where plasma-based thin film technology is a critical function in their manufacturing process. This would include the manufacture of semiconductors, CD-ROMs, DVDs, compact disks, flat panel displays, disk drives, optical and architectural glass. In addition, Advanced Energy provides the power conversion and control system solutions of choice to a growing number of general applications including instrumentation, telecommunications, automotive, food packaging, and tool industries. Founded in 1981, AE is a publicly held company traded on Nasdaq under the symbol AEIS.