Positive resist image by dry etching: New dry developed positive working system for electron beam and deep ultraviolet lithography

Mihov

Advances in Resist Technology and Processing XX

et al. 2003

Focused Ion beam (FIB) lithography has significant advantages over the electron beam counterpart in terms of resist sensitivity, backscattering and proximity effects. However, combining the FIB lithography with Top Surface Imaging (TSI) will extend its advantages by allowing anisotropic processing of thicker resist layers. This paper reports the development of novel single layer lithography process by combining focused Ga + ion beam (Ga + FIB) lithography, silylation and oxygen dry etching. The Negative Resist Image by Dry Etching (NERIME) is a TSI scheme for DNQ/novolak based resists and can result in either positive or negative resist images depending on the extent of the ion beam exposure dose. Results show that Ga + ion beam dose in the range of 1µC/cm 2 to 50µC/cm 2 at 30keV can successfully prevent silylation of the resist, thus resulting in the formation of positive image after the dry etching. A negative image can be formed by using a second Ga + ion beam exposure with a dose higher than 900µC/cm 2 at 30keV to pattern lines into the original exposed resist area. It was observed that resist regions exposed to such high doses can effectively withstand oxygen dry development, thus giving formation of negative resist image. In this study, nanometer resist patterns with high aspect ratio up to 15 were successfully resolved due to the ion beam exposure and anisotropic dry development. This novel TSI scheme for ion beam lithography could be utilized for the fabrication of critical CMOS process steps, such as deep isolation trench formation and lithography over substantial topography.

Section: Top Surface Imaging Schemesmentioning

confidence: 99%

Negative resist image by dry etching as a novel top surface imaging process for ion-beam lithography

Mihov

Advances in Resist Technology and Processing XX

et al. 2003

Advances in Resist Materials and Processing Technology XXVI

“…The patterning approach was inspired by PRIME process [16] in which a pattern of phenolic groups is created and silylated to give a contact mask against O 2 plasma etching. Referring to this process, a trilayer imaging system was established, including a top acid feeder layer, OTL layer and a bottom imaging layer.…”

Section: Patterning Through a Side Chain Crystal Polymermentioning

confidence: 99%

Fundamental study of optical threshold layer approach towards double exposure lithography

Berro

Cho

et al. 2009

ABSTRACT193 immersion lithography has reached its maximal achievable resolution. There are mainly two lithographic strategies that will enable continued increase in resolution. Those are being pursued in parallel. The first is extreme ultraviolet (EUV) lithography and the second is double patterning (exposure) lithography. EUV lithography is counted on to be available in 2013 time frame for 22 nm node [1] . Unfortunately, this technology has suffered several delays due to fundamental problems with source power, mask infrastructure, metrology and overall reliability [2] . The implementation of EUV lithography in the next five years is unlikely due to economic factors. Double patterning lithography (DPL) is a technology that has been implemented by the industry and has already shown the proof of concept for the 22nm node [3] .This technique while expensive is the only current path forward for scaling with no fundamental showstoppers for the 32nm and 22nm nodes. Double exposure lithography (DEL) is being proposed as a cost mitigating approach to advanced lithography. Compared to DPL, DEL offers advantages in overlay and process time, thus reducing the cost-of-ownership (CoO) [4][5] . However, DEL requires new materials that have a non-linear photoresponse. So far, several approaches were proposed for double exposure lithography, from which Optical Threshold Layer (OTL) was found to give the best lithography performance according to the results of the simulation [4][5] . This paper details the principle of the OTL approach. A photochromic polymer was designed and synthesized. The feasibility of the material for application of DEL was explored by a series of evaluations.

J. Photopol. Sci. Technol.

“…An increase in etch resistivity can be attained, for example, through functionalization of the organic material with silicon through soaking in hexamethyldisilizane (HMDS). This method called silylation was first introduced by Roland et al in 1985 in DESIRE [18] process and later utilized in it derivatives -PRIME, SUPER, SAHR and other processes [19][20][21]. When SIS is followed by ashing step it can be used to form 3D structures using different resist pattern as a template.…”

Section: Introductionmentioning

confidence: 99%

Sequential Infiltration Synthesis for Line Edge Roughness Mitigation of EUV Resist

Baryshnikova

Simone²,

Knaepen³

et al. 2017

It is well known that high line-edge roughness (LER) and line-width roughness (LWR) are one of the key problems hindering utilization of extreme ultraviolet lithography (EUVL) in fabrication of semiconductor devices at advanced technology nodes where pattern with sub-20 nm half pitch lines and spaces is required. Sequential infiltration synthesis (SIS) has never been used before in lithography for line-edge roughness mitigation, but this concept has proved its value for 14 nm half pitch block copolymer lines formed by directed self-assembly. During this process an inorganic scaffold is being deposited inside the resist material after performing several sequential infiltration cycles with metal-organic precursor and its oxidizing agent. Etching in oxygen atmosphere after is required to transform former resist pattern into metal oxide one and improve (up to 40%) the pattern roughness. In this paper, for the first time we demonstrate feasibility of sequential infiltration synthesis (SIS) for smoothing of EUV resist lines.