The ability to successfully release a Microelectromechanical system (MEMS) is a critical processing step of a MEMS device. Due to the inherent proximity of the moving structure and the surrounding surfaces, the final drying process can lead to 'stiction' of the structure that cannot be released. The amount of stiction on a surface micromachined polysilicon structure is dependent upon the various drying techniques employed. A comparison is made between a vapor isopropyl alcohol system, and a Marangoni drying system. The IPA system creates a meniscus at the bottom of the wafer and dries up, while the Marangoni system works in the opposite mode. Identical polysilicon test structures were used for the experiments. Experiments were performed with the IPA and Marangoni dryers using various MEMS structures to determine if there were increases in yields that were design dependent. The initial results obtained from these experiments indicate the Marangoni dryer increased the yield uniformity within a lot and lot to lot.

Date Published: 30 August 1999
PDF: 7 pages
Proc. SPIE 3874, Micromachining and Microfabrication Process Technology V, (30 August 1999);

Published in SPIE Proceedings Vol. 3874:
Micromachining and Microfabrication Process Technology V
James H. Smith; Jean Michel Karam, Editor(s)