Microelectronic Engineering 50 (2000) 7–14 www.elsevier.nl / locate / mee Electrical and adhesion properties of plasma-polymerised ultra-low k dielectric films with high thermal stability * M. Uhlig , A. Bertz, M. Rennau, S.E. Schulz, T. Werner, T. Gessner Center of Microtechnologies, Chemnitz University of Technology, D-09107 Chemnitz, Germany Abstract New intermetal dielectrics with dielectric constants ( k) less than the dielectric constant of the conventionally used SiO 2 ( k 5 3.9) are required for the fabrication of low voltage integrated circuits due to their ability to decrease signal delay time, crosstalk and power dissipation. In this paper results of depositing and investigating CF polymers will be presented. The films were deposited in a single wafer PECVD (plasma enhanced chemical vapor deposition) equipment (Secon 251) using a mixture of C, F and H containing gases. The polymer films are stable for temperatures as high as 4258C (shrinkage , 1%) maintaining a dielectric constant k even lower than 2.0 (depending on the deposition parameters and annealing processes). Furthermore, the adhesion of the CF films on top of several inorganic materials could be proved by tape test and following CMP processing. ICP patterned vias (polymer thickness: 1 mm; aspect ratio: 5) showed strong vertical profile.  2000 Elsevier Science B.V. All rights reserved. Keywords: Low k dielectric; CF polymer; PECVD; Dielectric constant; Adhesion 1. Introduction The requirements for an ongoing miniaturization and augmentation of storage capability and processing speed cannot be met with existing solutions. New materials must be introduced into IC fabrication. The use of advanced intermetal dielectrics to reduce the capacitance seems to be more important than the decrease of the resistivity provided by the substitution of aluminum by copper [1]. The reason is that the capacitance affects the device in three ways. The clock speed can be increased due to lower signal delay time of interconnects, crosstalk will be reduced between parallel lines and the power dissipation can also be decreased. Therefore, the application of new intermetal dielectrics with very low permittivity (low k material) is required. The demand of the semiconductor industry for the near future is to have available a dielectric material with k # 2.5 for sub 0.18 mm technology [2]. Among all new methods for the fabrication of low k material today three different groups of low k material seem to be applicable: *Corresponding author. Fax: 1 49-371-531-3131. E-mail address: m.uhlig@chemie.tu-chemnitz.de (M. Uhlig) 0167-9317 / 00 / $ – see front matter  2000 Elsevier Science B.V. All rights reserved. PII: S0167-9317(99)00258-0