[0001] This application claims the benefit of U.S. Provi› sional Application No. 62/590,516, entitled "METHOD OF FORMING AN ENHANCED UNEXPOSED PHOTORE› SIST LAYER" and filed on Nov. 24, 2017, the disclosure of which is hereby incorporated herein by reference. 

[0002] The present disclosure generally relates to methods and systems for manufacturing electronic devices. More particularly, the disclosure relates to methods of forming an enhanced unexposed photoresist layer. 

[0003] As the trend has pushed semiconductor devices to smaller and smaller sizes, different patterning techniques have arisen. These techniques include immersion (ArF) lithography with an exposure radiation at 193 nm combined with double or quadruple patterning, extreme ultraviolet lithography (EUV) with an exposure radiation around 13.5 nm, and EUV combined with double or quadrupole pattern› ing. 

[0004] The patterning techniques may utilize at least one photoresist disposed on a substrate to enable high resolution patterning of the substrate by the exposure radiation of a lithography system. To satisfy the requirements of both high resolution and low line-edge roughness, the photoresist may be a thin layer. 

[0005] However, photoresists may have several draw› backs. In particular, high resolution photoresists may have low sensitivity to the radiation used in the lithography step. The sensitivity of the unexposed photoresist may be defined as the minimum energy in mJ/cm2 that may be required to generate a well-defined feature in the photoresist on the substrate. The sensitivity of a photoresist is important when using deep ultraviolet (ArF) or extreme ultraviolet (EUV) exposure radiation. For example in lithography the radiation intensity generated by the tool may be low and therefor the throughput of the tool may be low if a photoresist is used with a low sensitivity. 

[0006] It may therefore be advantageous to enhance the sensitivity of the unexposed photoresist to the exposure radiation of the lithography tool to enhance the throughput of the lithographic tool. 

[0007] In accordance with at least one embodiment of the invention there is provided a method of forming an enhanced unexposed photoresist layer with an increased sensitivity to exposure radiation from an unexposed photo› resist layer on a substrate by: 

[0008] providing the substrate with the unexposed photo› resist layer in a reaction chamber; 

[0009] providing a first precursor comprising at least a portion of a photosensitizer sensitive to exposure radiation to the substrate in the reaction chamber thereby infiltrating the unexposed photoresist layer on the substrate with the first precursor for a first period Tl. By infiltrating the unexposed photoresist layer on the substrate with the first 

## METHOD OF FORMING AN ENHANCED UNEXPOSED PHOTORESIST LAYER 

## CROSS-REFERENCE TO RELATED APPLICATION 

## FIELD OF INVENTION 

## BACKGROUND 

## SUMMARY 

precursor comprising at least a portion of a photosensitizer sensitive to exposure radiation for a first period Tl the amount of photo sensitizer can be increased in the unexposed photoresist layer. The amount of photosensitizer in the photoresist may be limited for example because of its insolubility in the photoresist before spinning it on the substrate. By infiltrating at least a portion of the photosen› sitizer after the unexposed photoresist layer is spun on the substrate extra photosensitizer may be provided in the photoresist layer. 

[0010] For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described herein above. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accor› dance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advan› tages as taught or suggested herein without necessarily achieving other objects or advantages as may be taught or suggested herein. 

[0011] All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments will become readily apparent to those skilled in the art from the following detailed description of certain embodiments having reference to the attached figures, the invention not being limited to any particular embodiment(s) disclosed. 

## BRIEF DESCRIPTION OF THE FIGURES 

[0012] These and other features, aspects, and advantages of the invention disclosed herein are described below with reference to the drawings of certain embodiments, which are intended to illustrate and not to limit the invention. 

[0013] FIG. 1 is a flowchart in accordance with at least one embodiment of the invention. 

[0014] FIG. 2 illustrates an exemplary system in accor› dance with various exemplary embodiments of the disclo› sure. 

[0015] FIG. 3 illustrates an additional exemplary system in accordance with various exemplary embodiments of the disclosure. 

[0016] It will be appreciated that elements in the figures are illustrated for simplicity and clarity and have not nec› essarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of illustrated embodiments of the present disclosure. 

## DETAILED DESCRIPTION 

[0017] Although certain embodiments and examples are disclosed below, it will be understood by those in the art that the invention extends beyond the specifically disclosed embodiments and/or uses of the invention and obvious modifications and equivalents thereof. Thus, it is intended that the scope of the invention disclosed should not be limited by the particular disclosed embodiments described below. 

[0018] Embodiments in accordance with the invention relate to the combination of hard masks with a film infil› tration processes. This combination of a unexposed photo› resist layer and infiltration processes can alter the properties 

