Methods for making nearly planar dielectric films in integrated circuits

Abstract

In the fabrication of integrated circuits, one specific technique for making surfaces flat is chemical-mechanical planarization. However, this technique is quite time consuming and expensive, particularly as applied to the numerous intermetal dielectric layers—the insulative layers sandwiched between layers of metal wiring—in integrated circuits. Accordingly, the inventor devised several methods for making nearly planar intermetal dielectric layers without the use of chemical-mechanical planarization and methods of modifying metal layout patterns to facilitate formation of dielectric layers with more uniform thickness. These methods of modifying metal layouts and making dielectric layers can be used in sequence to yield nearly planar intermetal dielectric layers with more uniform thickness.

Description

RELATED APPLICATIONS [0001] This application is a Divisional of U.S. application Ser. No. 10 / 677,057, filed Sep. 30, 2003, which is a Divisional of U.S. application Ser. No. 09 / 801,265, filed Mar. 7, 2001, now U.S. Pat. No. 6,627,549, which claims priority to U.S. Provisional App. 60 / 187,658, filed on Mar. 7, 2000. This application further relates to U.S. application Ser. No. 10 / 926,471. All of these applications are incorporated herein by reference.TECHNICAL FIELD [0002] The present invention concerns methods of making integrated circuits, particularly methods of making metal masks and dielectric, or insulative, films. BACKGROUND OF THE INVENTION [0003] Integrated circuits, the key components in thousands of electronic and computer products, are interconnected networks of electrical components fabricated on a common foundation, or substrate. Fabricators typically build the circuits layer by layer, using techniques, such as doping, masking, and etching, to form thousands and even mi...

AI Technical Summary

Benefits of technology

These methods reduce the need for chemical-mechanical planarization, achieve more uniform thickness in dielectric layers, and improve electrical properties by minimizing shorting and crosstalk, while maintaining planarity and reducing fabrication costs.

Problems solved by technology

Moreover, hills and valleys can reflect light undesirably onto other regions of a layer and add undesirable features, such as notches, to desired features.

Unfortunately, conventional methods of forming these intermetal dielectric layers suffer from at least two problems.

First, the process of chemical-mechanical planarization is not only relatively costly but also quite time consuming.

And second, the thickness of these layers generally varies considerably from point to point because of underlying wiring.

Occasionally, the thickness variation leaves metal wiring under a layer too close to metal wiring on the layer, encouraging shorting or crosstalking.

Crosstalk, a phenomenon that also occurs in telephone systems, occurs when signals from one wire are undesirable transferred or communicated to another nearby wire.

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