Battelle Memorial Institute

Pacific Northwest Division

Jerome C Birnbaum

Glen E Fryxell

Suresh Baskaran

Glen C Dunham

Christopher Andrew Coyle

Jun Liu

Xiaohong Shari Li

Ralph E Williford

Gary D Maupin

Karel Domansky

Nathan J Kohler

Suntharampillai Thevuthasan

Shari Li Xiaohong

Porous ceramic and hybrid ceramic films are useful as low dielectric constant interlayers in semiconductor interconnects. (Hybrid ceramic films are defined as films that contain organic and ceramic molecular components in the structure, as, for example, organosilicates). This invention describes the usefulness of humidity treatments (using specific temperature/humidity treatments as illustrative examples) in increasing mechanical integrity of porous dielectric films with minimal detrimental effect on film porosity or dielectric constant and with no adverse impact on film quality. The efficacy of such treatments is illustrated using surfactant-templated mesoporous silicate films as an example. This invention also describes a specific family of additives to be used with highly pure alkali-metal-free ceramic and hybrid precursors for such dielectric films that will enable better control of the film porosity and quality and lower dielectric constants with the required mechanical integrity. The efficacy of such additives is illustrated using surfactant-templated mesoporous silicate films as a model example. The invention should be broadly applicable to any cross-linked ceramic or hybrid ceramic films (including silicate and organosilicate films, and especially highly porous forms of the films for low-dielectric constant applications). The invention has been found to be particularly effective with surfactant-templated silicate films with nanometer-scale porosity. The invention in either embodiment should also be applicable to evaporation-induced formation of other cross-linked shapes such as fibers and powders.

Method for producing high purity low dielectric constant ceramic and hybrid ceramic films

Vacuum/gas phase reactor embodiments used in gas phase dehydroxylation and alkylation reactions are described in which the substrate could be subjected to high vacuum, heated to target temperature, and treated with silane as quickly and efficiently as possible. To better facilitate the silylation and to increase the efficiency of the process, the reactor is designed to contain quasi-catalytic surfaces which can act both as an &ldquo;activator&rdquo; to put species in a higher energy state or a highly activated state, and as a &ldquo;scrubber&rdquo; to eliminate possible poisons or reactive by-products generated in the silylation reactions. One described embodiment is a hot filament reactor having hot, preferably metallic, solid surfaces within the reactor's chamber in which wafers having mesoporous silicate films are treated. Another is an IR reactor having upper and lower quartz windows sealing the upper and lower periphery of an aluminum annulus to form a heated chamber. Finally, a flange reactor is described that includes a flange base and lid forming a tiny chamber therein for a wafer, the reactor being heated by conduction from a hot sand bath. The dehydroxylation and alkylation treatment of mesoporous silica films produces treated films exhibiting low dielectric constant and high elastic modulus.

Vacuum/gas phase reactor for dehydroxylation and alkylation of porous silica

The present invention is a mesoporous silica film having a low dielectric constant and method of making having the steps of combining a surfactant in a silica precursor solution, spin-coating a film from this solution mixture, forming a partially hydroxylated mesoporous film, and dehydroxylating the hydroxylated film to obtain the mesoporous film. It is advantageous that the small polyoxyethylene ether surfactants used in spin-coated films as described in the present invention will result in fine pores smaller on average than about 20 nm. The resulting mesoporous film has a dielectric constant less than 3, which is stable in moist air with a specific humidity. The present invention provides a method for superior control of film thickness and thickness uniformity over a coated wafer, and films with low dielectric constant.

Mesoporous silica film from a solution containing a surfactant and methods of making same

Growing community of inventors

Richland, WA, United States of America

Jerome C Birnbaum