Heavy metal incorporated helium ion active hybrid non-chemically amplified resists: Nano-patterning with low line edge roughness

Abstract

Helium (He) ion lithography is being considered as one of the most promising and emerging technology for the manufacturing of next generation integrated circuits (ICs) at nanolevel. However, He-ion active resists are rarely reported. In this context, we are introducing a new non-chemically amplified hybrid resist (n-CAR), MAPDSA-MAPDST, for high resolution He-ion beam lithography (HBL) applications. In the resist architecture, 2.15 % antimony is incorporated as heavy metal in the form of antimonate. This newly developed resists has successfully used for patterning 20 nm negative tone features at a dose of 60 μC/cm2. The resist offered very low line edge roughness (1.27±0.31 nm) for 20 nm line features. To our knowledge, this is the first He-ion active hybrid resist for nanopatterning. The contrast (γ) and sensitivity (E0) of this resist were calculated from the contrast curve as 0.73 and 7.2 μC/cm2, respectively.

EUV photofragmentation study of hybrid nonchemically amplified resists containing antimony as an absorption enhancer

“…Finally, the developed 2.15%-MAPDSA–MAPDST hybrid resist exhibits the following characteristics: 22,23,55 …”

“…23 The present results showed that the SbF 6 À inorganic moiety may control the deposited energy on the resist by gradual homolysis of Sb-F bonds which lost uorine atoms at a much lower rate that the sulfonium triate functionality. Finally, the developed 2.15%-MAPDSA-MAPDST hybrid resist exhibits the following characteristics: 22,23,55 (i) The resist offered a maximum resolution of 20 nm line features with the maximum sensitivity of 22 mJ cm À2 under EUVL (see the image in the ESI †).…”

“…Recently, the concepts of hybrid resists incorporating EUV absorbing metals such as antimony in a n-CAR platform and the EUV lithography results have also been studied. 22,23 The n-CAR 1.5 and 2.15% MAPDSA-MAPDST (where MAPDST ¼ (4-(methacryloyloxy) phenyl)dime-thylsulfoniumtriate and MAPDSA ¼ (4-(methacryloyloxy) phenyl)dimethylsulfoniumhexauoroantimonate) resists revealed improved sensitivity as compared to the poly-MAPDST resist for EUVL in spite the low concentration of hexa-uoroantimonate used. The sizing dose used for high resolution line patterns when the SbF 6 À units were incorporated in the 1.5% and 2.15% resists resulted in the improvement of the resists' sensitivity by 2.5 and 10 times, respectively, compared to the poly-MAPDST resist.…”

Multifunctional Structured Platforms: From Patterning of Polymer-Based Films to Their Subsequent Filling with Various Nanomaterials

“…For example, taking into account the characteristics of the resist, Reddy et al have fabricated sharp inner walls in a non-chemically amplified hybrid copolymer resist made through copolymerization of an organic monomer with another inorganic monomer. Using He ions, they have obtained 20 nm wide line patterns ( Figure 4 g) separated by different lateral distances [ 78 ].…”

A review of defect engineering, ion implantation, and nanofabrication using the helium ion microscope

“…The high sensitivity to helium ions of the inorganic HafSOx resist (designed for EUV lithography) has been explored [117] and the unique potential to use HIBL to pre-screen EUV resists has been evaluated [118][119][120]. The advantages of HIBL have also been highlighted using a number of other novel resists, including a fullerene-based molecular resist [121], a tetracene molecular resist [122], and various organic-inorganic resists [123][124][125][126][127][128][129]. The enhanced sensitivity of resists to helium ions has been attributed to the higher secondary electron emission yield and the fact that the helium ions deposit their energy over much shorter distances in the resist, thus increasing the local energy density.…”