On the closed-loop control of an argon plasma process

Iordanov, Petar; Keville, Bernard; Ringwood, John V.; Doherty, Sean; Faulkner, Ronan

doi:10.1049/cp:20060476

Cited by 2 publications

(1 citation statement)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The role of the Host PC is to upload the software to be executed in real time by the Target PC, to start it, stop it and to monitor it while running using the RS-232 interface. This kind of configuration gives a considerable amount of computational power, allowing the implementation of complex control algorithm for the plasma process (Iordanov et al, 2006).…”

Section: Plasma Process Monitoring and Controlmentioning

confidence: 99%

IMPEDANCE MATCHING CONTROLLER FOR AN INDUCTIVELY COUPLED PLASMA CHAMBER - L-type Matching Network Automatic Controller

Bacelli

Ringwood

Iordanov

2007

Proceedings of the Fourth International Conference on Informatics in Control, Automation and Robotics

View full text Add to dashboard Cite

Plasma processing is used in a variety of industrial systems, including semiconductor manufacture (deposition and etching) and accurate control of the impedance matching network is vital if repeatable quality is to be achieved at the manufacturing process output. Typically, impedance matching networks employ series (tune) and parallel (load) capacitors to drive the reflection coefficient on the load side of the network to zero. The reflection coefficient is normally represented by real and imaginary parts, giving two variables to be controlled using the load and tune capacitors. The resulting problem is therefore a nonlinear, multivariable control problem. Current industrial impedance matching units employ simple single-loop proportional controllers, which take no account of interaction between individual channels and, in many cases, may fail to tune altogether, if the starting point is far away from the matching point. A hierarchical feedback controller is developed which, at the upper level, performs a single-loop tuning, but with the important addition of a variable sign feedback gain. When convergence to a region in the neighbourhood of the matching point is achieved, a dual single-loop controller takes over, which gives fine tuning of the matching network.

show abstract

Section: Plasma Process Monitoring and Controlmentioning

confidence: 99%