CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2019-0006959 filed in the Korean Intellectual Property Office on Jan. 18, 2019, the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to a hardmask composition having anti-reflective film characteristics useful for a lithographic process, and more particularly to a polymer containing an indolocarbazole-based aromatic ring having strong absorption in an ultraviolet ray wavelength region, and a hardmask composition containing the same.

(b) Description of the Related Art

Recently, while the semiconductor industry has been increasingly demanding a miniaturization process, an effective lithographic process is indispensable for realizing such ultra-fine technology. In particular, the demand for new materials for the hardmask process, which has become extremely indispensable in the etching process, is increasing.

In general, the hardmask layer serves as an intermediate film that transfers a fine pattern of a photoresist to a lower substrate layer through a selective etching process. Accordingly, the hardmask layer is required to have properties such as chemical resistance, heat resistance, and etching resistance so as to withstand multiple etching processes. As a hardmask layer used in the related art, an amorphous carbon layer (ACL) made by a chemical vapor deposition (CVD) method has been used, and as drawbacks about the quality of the ACL, there are many inconveniences in which the ACL is used due to facility investments requiring high unit costs and photolithographic alignment problems caused by particles and layer opacity generated during the process.

Recently, a spin-on hardmask, which is formed by a spin-on coating method, has been introduced instead of the chemical vapor deposition method. The spin-on coating method uses an organic polymer material that is soluble in a solvent to form a hardmask composition, but in this case, the most important characteristic needs to form an organic polymer coating film that simultaneously has etching resistance.

However, two characteristics required for such an organic hardmask layer, that is, the characteristics for solubility and etching resistance, required a hard mask composition that can satisfy all of the characteristics in a mutually contradictory relationship. Materials, which are introduced into semiconductor lithographic processes while satisfying the characteristics of the organic hardmask material, have been recently introduced (Korean Patent Application Laid-Open No. 10-2009-0120827, Korean Patent Application Laid-Open No. 10-2008-0107210, and International Patent WO 2013100365 A1, and these materials are hardmask materials using a copolymer having an appropriate molecular weight, which is synthesized by an existing phenol resin preparation method using a hydroxypyrene.

However, even though the semiconductor lithographic process has been increasingly subjected to a miniaturization process in recent years, the organic hardmask material has reached a step where it is difficult to sufficiently serve as a mask due to a shortage of etching selectivity in the etching process compared to the existing inorganic hardmask material. Therefore, there is an urgent need for the introduction of an organic hardmask material that is more optimal for the etching process.

The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.

SUMMARY OF THE INVENTION

The present invention has been made in an effort to provide a hardmask polymer having excellent polymer solubility and simultaneously having high etching selectivity and sufficient resistance to multiple etching, and a composition containing the same.

The present invention has also been made in an effort to provide a novel hardmask polymer which may minimize the reflectivity between a resist and a backing layer, and thus may be used for performing a lithographic technology, and a composition containing the same.

The hardmask composition according to exemplary embodiments of the present invention is an anti-reflective hardmask composition including: (a) a polymer composed of an indolocarbazole represented by the following Chemical Formula 1 or a polymeric blend containing the same; and

(b) an organic solvent.



The hardmask composition based on the indolocarbazole-based polymer according to the embodiments of the present invention has a very high polymerization rate as compared to the existing phenol-based polymer.

The hardmask composition based on the indolocabazole polymer according to the embodiments of the present invention has a very high packing density, and thus has characteristics in which when a thin film is formed, etching resistance is excellent while the film density is increased. Accordingly, it is possible to provide a lithographic structure which has sufficient resistance to multiple etching due to a higher etching selectivity ratio than that of an existing organic hardmask, and thus has an excellent pattern evaluation result.

The hardmask composition based on the indolocarbazole-based polymer according to exemplary embodiments of the present invention can minimize the reflectivity between a resist and a backing layer by having a refractive index and an absorptivity within useful ranges as an anti-reflective film in a deep UV region such as ArF (193 nm) and KrF (248 nm) when a film is formed.

