Here is the abstract you requested from the wirebond_2008 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Argon Plasma Cleaning of Fluorine, Organic and Oxide Contamination to Improve Wire Bonding|
|Keywords: Plasma, Cleaning, Wirebonding|
|Commercially-available plasma cleaning systems using Argon gas can be used for effectively cleaning Fluorine, organic, and oxide contamination from the surface of a variety of microelectronic wire bond pads in order to measurably improve the performance and reliability of wire bonding. Argon-based plasma cleaning has significant benefits for wire bonding, because it removes contamination via ion bombardment (also known as “sputtering”) without causing a chemical reaction or oxidation on the surface of the bond pad. Using Argon plasma, contaminants are knocked off of the surface of the substrate at the molecular level, then exhausted out of the process chamber before re-deposition can occur. Moreover, Argon plasma is effective for many types of contamination such as Fluorine, organic contamination and metal oxides, because it is largely non-selective and removes these contaminants at a similar rate. Microelectronic devices/substrates that can be wire bonded after plasma cleaning come in many forms: BGA strips, metal lead frames, semiconductor die, and packages held in boats or trays for processing. In addition to contamination removal, Argon plasma treatments are also used to physically roughen surfaces, and activate chemical bonds on a surface in order to improve bondability and adhesion. Argon plasma cleaning processes are highly flexible and can improve wire bonding for many kinds of materials. By changing process parameters such as gas flow, pressure, power, and chamber configuration, commercially-available plasma cleaning systems can provide a plasma cleaning process to improve many types of wire bonding. Argon plasma cleaning performance is both measurable and traceable: (1) Wettability testing can be done immediately after plasma cleaning to demonstrate effectiveness, (2) Wires can be bonded to both cleaned and non-cleaned pads, then pull/shear tests conducted, (3) Cleaned- and non-cleaned finished packages can be reliability tested (i.e. stress/temperature/power cycled) in order to confirm improvements.|
|Scott D. Szymanski, Global Marketing Manager
March Plasma Systems