Polymeric protective coatings for MEMS wet-etch processes was written by Ruben, Kimberly A.;Flaim, Tony D.;Li, Chenghong. And the article was included in Proceedings of SPIE-The International Society for Optical Engineering in 2004.Reference of 763-69-9 The following contents are mentioned in the article:
Microelectromech. systems (MEMS) device manufacturers today are faced with the challenge of protecting electronic circuitry and other sensitive device structures during deep Si wet-etch processes. Etch processes of this nature require prolonged exposure of the device to harsh corrosive mixtures of aqueous acids and bases at higher than ambient temperatures A need exists for a spin-applied polymeric coating to prevent the exposure of such circuitry against the corrosive etchants. The challenge exists in developing protective coatings that will not decompose or dissolve in the etchants during the etch process. Such coatings require superior adhesion to the substrate without destroying the sensitive features below. Brewer Science, Inc., has developed a multilayer coating system for basic etchants which is compatible with a variety of semiconductor materials and offers protection against concentrated KOH etchants at prolonged exposure times of >8 h. In addition, a 2nd multilayer coating system is being developed for use with strong HF and other various mixed acid etchants (MAEs) for exposures of 30 min or longer. These materials are specifically designed to protect circuitry subjected to concentrated MAEs during the wafer thinning processes used by MEMS device manufacturers. This study involved multiple reactions and reactants, such as Ethyl 3-ethoxypropanoate (cas: 763-69-9Reference of 763-69-9).
Ethyl 3-ethoxypropanoate (cas: 763-69-9) belongs to esters. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. Because of their lack of hydrogen-bond-donating ability, esters do not self-associate. Consequently, esters are more volatile than carboxylic acids of similar molecular weight.Reference of 763-69-9
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics