Multilayer copper/polyimide interconnect structures were fabricated using a reactive-ion-etching-based lift-off technique. Conductor cross-sectional area control, planarity, and a gap-free structure were made possible by the use of a novel siloxane-polyimide. The resultant structure consisted of two signal wiring layers between two ground planes with a nominal impedance of 40 Ω. Although redundant metallization processes were found to repair open lines, they resulted in an increase of the number of processing steps and could result in an increase of defects. Stud chain structures were found to survive cooling to 77 K with very little change in their characteristics, while heating of the copper interconnections to 350°C in a reducing environment reduced their resistance by 3%

Different types of polyfunctional organosilicon compounds (chloro-, alkoxy-, acetoxysilanes, linear and cyclic silazanes and silylamines) were studied as silylating agents in the diffusion limited heterogeneous silylation process. It was shown that compounds with reactive silicon nitrogen bonds were most effective at silylating AZ4110 resist. Surprisingly, it was found that the higher the organosilicon compound reactivity, the lower the degree of silylation of the photoresist. One of the most effective silylating agents was found to be bis (dimethylamino)dimethylsilane (BDAMS). The chemistry of silylation of both novolak resins and 1,2,5-naphthoquinone diazo type photoactive compounds (PAC) leading to the formation of crosslinked materials is discussed. The formation of triazine derivatives was also detected. Photoresist images which were UV irradiated at 365 nm after exposure and development were found to be more amenable to silylation than those which had not.

This paper discusses a simplified “lift-off” process, which consists of two layers. This consists of an underlayer of soluble, thermally stable polyimide, and a new process, “silylation”, which converts typical positive photoresists into oxygen RIE barriers. The uses of this new material and process for chip and packaging applications are described in this paper.

This paper discusses a simplified ‘‘silylation’’ process, which converts typical diazo-type photoresists into oxygen plasma etch barriers that are insoluble and thermally stable. Previous workers have reported on a silylation process that incorporates silicon in the resist in the gas phase. This paper reports on the use of a bifunctional silylation agent, which when diffused into the patterned resist using a solvent carrier, crosslinks the novolac resin, incorporating silicon in the matrix. The mechanism and the properties of the resist film after silylation such as thermal stability, reactive ion etch (RIE) resistance, silicon content, and solubility will be discussed.

This paper describes new types of organosilicon photoresists, sensitive throughout the ultraviolet region from 2000 to 45Å. The synthesis is based upon a simple condensation reaction of 3-aminopropyl-substituted polysiloxanes with photosensitive naphthoquinone diazosulfonyl chlorides.