Silicon nitride films and methods

Abstract

Described are methods of making SiN materials on substrates, particularly SiN thin films on semiconductor substrates. Improved SiN films made by the methods are also included.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority benefit under 35 USC §119(e) of U.S. provisional patent application No. 61 / 324,710, filed Apr. 15, 2010, and U.S. provisional patent application No. 61 / 372,367, filed Aug. 10, 2010, and U.S. provisional patent application No. 61 / 379,081, filed Sep. 1, 2010, and U.S. provisional patent application No. 61 / 417,807, filed Nov. 29, 2010, each of which is incorporated herein by reference in its entirety and for all purposes. This application is related to U.S. patent application Ser. No. ______ [Attorney docket No. NOVLP405], and U.S. patent application Ser. No. ______ [Attorney docket No. NVLS003674], each filed on the same day as the instant disclosure and each incorporated herein by reference in its entirety and for all purposes.INTRODUCTION[0002]1. Field[0003]The present disclosure relates generally to formation of SiN materials on substrates. More particularly, the disclosure relates to formation of SiN fil...

AI Technical Summary

Benefits of technology

[0012]In some embodiments, the SiN film produced has an undesirable carbon content. This in-film carbon may result in electrical leakage and may render the film unusable for some dielectric barrier applications. Methods described herein produce SiN films with less than 2% carbon, in one embodiment less than 1% carbon, in yet another embodiment less than 0.5% carbon. In some embodiments, the reduction in carbon residue is readily observable in FTIR spectra. One embodiment is a method of forming a silicon nitride material on a substrate, including: (a) forming a silicon nitride film on the substrate, said formation including: (i) providing the substrate in a reaction chamber; (ii) exposing the substrate to a silicon-containing reactant in the vapor phase so that the silicon-containing reactant is adsorbed onto the surface of the substrate; (iii) exposing the substrate to an nitrogen-containing reactant in the vapor phase so that the nitrogen-containing reactant is adsorbed onto the surface of the substrate; (iv) igniting a plasma while the nitrogen-containing reactant is present in the vapor phase; and then, (b) exposing the silicon nitride film to a hydrogen containing plasma. The hydrogen plasma reduces carbon content of the film. In one embodiment, the hydrogen plasma is generated using hydrogen (H2) and a carrier gas such as nitrogen, helium or argon.

Problems solved by technology

One issue with SiN films is the relatively high temperatures used to form the films, for example, in Front End of Line (FEOL) applications, SiN films are typically deposited by chemical vapor deposition (CVD) in a reactor at greater than 750° C. using dichlorosilane and ammonia.

Another issue with SiN film depositions is the occurrence and / or buildup of amine salts in the reaction chamber.

Another issue with SiN films is, in certain instances, unwanted carbon content in the film due to carbon content of reactants used to form the SiN film.

One way that such carbon content is removed is by high temperature anneal, for example, greater than 600° C., and thus the aforementioned finer features are jeopardized.

In some embodiments, the SiN film produced has an undesirable carbon content.

This in-film carbon may result in electrical leakage and may render the film unusable for some dielectric barrier applications.

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