Integrated fab process for metal oxide EUV photoresist

Self Cite

Limitations on current performances of the chemically amplified resists (CAR), as well as the productivity driven low exposure dose requirements (below 20 mJ/cm 2 ), have brought the researchers to look at a novel class of materials as possible alternative to the CA resists to simultaneously achieve resolution, line-width roughness (LWR) and sensitivity. In 2014, imec has started a new project to look into novel materials for EUV lithography with particular attention to metal containing materials (MCR) to explore alternative approaches that can offer superior characteristics in photoresist imaging: improved LWR and line collapse, high sensitivity and high etch resistance. In this paper we report the first assessment on the enablers of the MCRs from a manufacturing compatibility prospective, as metal cross-contamination and outgassing, to a device integration prospective through the patterning on the ASML NXE:3300 full field scanner exposure tool, the etch performances and new litho-etch integration scheme for 1x nm technology and below. The results obtained are highly promising and give a clear indication that other chemical paths in novel resist formulations are possible in advanced EUV lithography.

Section: Metal Containing Resist Challenges In Manufacturing Environmentmentioning

confidence: 99%

Metal-containing Materials as Turning Point of EUV Lithography

Simone¹,

Pollentier²,

Vandenberghe³

2015

Self Cite

“…Recently Kocsis et al, reported that some metal containing resists can print 9.5 nm L/S using EUV interference lithography tool, but this resist also needs ~50 mJ/cm 2 sensitivity [11]. As a brief conclusion, current EUV resists and processes have serious limitations on high volume manufacturing because industry requires both high resolution below 15 nm hp and high sensitivity below 20 mJ/cm 2 .…”

Section: Introductionmentioning

confidence: 99%

Negative-tone Imaging with EUV Exposure toward 13 nm hp

Tsubaki

Nihashi

Tsuchihashi

et al. 2016

Negative-tone imaging (NTI) with EUV exposure has major advantages with respect to line-width roughness (LWR) and resolution due in part to polymer swelling and favorable dissolution mechanics. In NTI process, both resist and organic solvents play important roles in determining lithography performances. The present study describes novel chemically amplified resist materials based on NTI technology with EUV using specific organic solvents. Lithographic performances of NTI process were described in this paper under exposures using ASML NXE:3300 EUV scanner at imec. It is emphasized that 14 nm hp was nicely resolved under exposure dose of 37 mJ/cm 2 without any bridge and collapse, which are attributed to the low swelling character of NTI process. Although 13 nm hp resolution was potentially obtained, a pattern collapse still restricts its resolution in case coating resist film thickness is 40 nm. Dark mask limitation due mainly to mask defectivity issue makes NTI with EUV favorable approach for printing block mask to produce logic circuit. A good resolution of CD-X 21 nm/CD-Y 32 nm was obtained for block mask pattern using NTI with usable process window and dose of 49 mJ/cm 2 . Minimum resolution now reaches CD-X 17 nm / CD-Y 23 nm for the block. A 21 nm block mask resolution was not affected by exposure dose and explored toward low dose down to 18 mJ/cm 2 by reducing quencher loading. In addition, there was a negligible amount of increase in LCDU for isolated dot pattern when decreasing exposure dose from 66 mJ/cm 2 to 24 mJ/cm 2 . On the other hand, there appeared tradeoff relationship between LCDU and dose for dense dot pattern, indicating photon-shot noise restriction, but strong dependency on patterning features. Design to improve acid generation efficiency was described based on acid generation mechanism in traditional chemically amplified materials which contains photoacid generator (PAG) and polymer. Conventional EUV absorber which comprises of organic compounds is expected to have 1.6 times higher EUV absorption than polyhydroxystyrene based on calculation. However, observed value of acid amount was comparable or significantly worse than polyhydroxystyrene.

“…Since the EUV photon energy is not react efficiently with an organic resist material because of having high transmittance, increasing the resist sensitivity is not so easy. In order to achieve high sensitive resist, some groups reported several methods [6] to introduce the high absorption compounds including such as hafnium and zinc [7][8][9], tin-oxide [10,11], and tellurium [12] in base resin. In order to evaluate the effect of the high absorption material, it is important to measure the EUV absorption accurately.…”

Section: Introductionmentioning

confidence: 99%

Absorption Coefficient Measurement Advanced Method of EUV Resist by Direct-Resist Coating on a Photodiode

Niihara

Mamezaki

Watanabe

et al. 2017

Since the resist thickness in EUV lithography of which base material mainly consists of an organic material is thin, the EUV photon energy is not be used efficiently for the EUV chemical reaction. In order to increase chemical reaction incidence in the EUV photon energy, a resist having a high-absorption material compounds for the EUV photons has been developed. It has been studied to increase the absorption including high-absorption materials such as hafnium and zinc, tin oxide, tellurium. For the development of the next-generation high sensitive resist materials, since it is significant to measure the EUV absorption coefficient accurately, it is necessary to measure the transmittance and resist thickness to obtain the absorption coefficient accurately. Thus, we have developed to evaluate the absorption coefficient of the EUV resist at BL 10 beamline of NewSUBARU synchrotron hlight facility. In the previous paper, we measured the EUV resist transmittance on a freestanding membrane. However, since it was very difficult to coat resist on a membrane with high uniformity, the transmittance could not be measured accurately. Thus, we have developed the precise transmittance measurement method by coating resist on a photodiode directly, and the resist thickness on a photodiode was measured by XRR accurately instead on conventional method. Finally, the accurate measurement of EUV resist absorption coefficient was achieved.