Applied Materials, Inc.

Robert L Hubbard

Iftikhar Ahmad

A method for densifying thermoplastics, particularly polyimides, for use in conjunction with electronic circuits while producing improved physical properties and a high degree of crystallinity, involves variable frequency microwave (VFM) processing at temperatures typically 100&#xb0; C. below the glass transition temperature or lower, for times of about 50 to 100 minutes. It is particularly applicable to polymers based on BPDA-PPD, but may also be generally applied to other intentionally designed polyimide structures with the same features. The invention enables the creation of layered structures involving integrated circuits with small feature sizes and overcoatings of polymers with high Tand other desirable properties.

Method of curing thermoplastics with microwave energy

A method for curing photosensitive polyimide (PSPI) films includes the steps of: depositing a PSPI film on a selected substrate, and curing the film by microwave heating at a selected temperature from about 200 to 340&#xb0; C. in a selected atmosphere containing an oxygen concentration from about 20 to 200,000 ppm. The process atmosphere may be static or flowing. The addition of oxygen improves the removal of acrylate residue and improves the Tof the cured film, while the low processing temperature characteristic of the microwave process prevents the oxygen from damaging the polyimide backbone. The method may further include the steps of photopatterning and developing the PSPI film prior to curing. The process is particularly suitable for dielectric films on silicon for electronic applications.

Method for microwave processing of photosensitive polyimides

A method for forming a multilayer structure comprises the steps of: depositing a first polymerizable layer on a substrate; applying microwave energy to the polymerizable layer while monitoring at least one property of the layer; and, ending the application of microwave energy when the monitored property indicates that the polymerizable layer has reached a desired degree of cure. The property monitored may be optical, e.g., Raman spectrum, or electrical, e.g., dielectric loss. This process control strategy lowers the overall thermal budget, and is especially suitable for curing polymer films on silicon. The method may be used repetitively to cure multiple layers of polymeric material when a thicker film is needed.

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Eugene, OR, United States of America

Robert L Hubbard