Relationship between sensitizer concentration and resist performance of chemically amplified extreme ultraviolet resists in sub-10 nm half-pitch resolution region

Abstract

The development of lithography processes with sub-10 nm resolution is challenging. Stochastic phenomena such as line width roughness (LWR) are significant problems. In this study, the feasibility of sub-10 nm fabrication using chemically amplified extreme ultraviolet resists with photodecomposable quenchers was investigated from the viewpoint of the suppression of LWR. The relationship between sensitizer concentration (the sum of acid generator and photodecomposable quencher concentrations) and resist performance was clarified, using the simulation based on the sensitization and reaction mechanisms of chemically amplified resists. For the total sensitizer concentration of 0.5 nm−3 and the effective reaction radius for the deprotection of 0.1 nm, the reachable half-pitch while maintaining 10% critical dimension (CD) LWR was 11 nm. The reachable half-pitch was 7 nm for 20% CD LWR. The increase in the effective reaction radius is required to realize the sub-10 nm fabrication with 10% CD LWR.

Line-Edge Roughness from Extreme Ultraviolet Lithography to Fin-Field-Effect-Transistor: Computational Study

“…and T are diffusion constant of acid, diffusion constant of base quenchers, rate constants of neutralization, rate constant of acid loss, rate constant of deprotection, concentration of base quenchers, concentration of protected unit, activation energy of acids, activation energy of quenches, activation energy of deprotection, ideal gas constant, time, and temperature, respectively [13,33]. For PEB process, equations (8-10) of acid and base quencher diffusion, deprotection reaction, and neutralization can reproduce experimental results [34,35]. When f LER is proportionality constant and m is normalized protected unit concentration, LER (≈ f LER /(dm/dx)) is proportional to protected unit fluctuation [36,37].…”

Effects of underlayer absorption coefficient on bridging risk in chemically amplified resist process for extreme ultraviolet lithography

“…The proton generation efficiency of the radical cation of the nonproton source was 0.3. 34) The dynamics of acids and PDQ during postexposure baking (PEB) were calculated by solving the reaction-diffusion equations 35) and using the Monte Carlo method. 36) The preneutralization between an acid and PDQ at RT 37,38) was taken into account.…”

“…The calculation method has been described in detail elsewhere. 35,36) The effective reaction radii for neutralization and catalytic chain reactions were 0.5 and 0.1 nm, respectively. Note that the effective reaction radii for catalytic chain reactions have been evaluated to be 0.06-0.16 nm for high-performance EUV resists.…”

Shielding effect of underlayer against secondary electrons generated in substrate in extreme ultraviolet lithography

“…29) The proton generation efficiencies of radical cations are listed in Table I. The dynamics of acids and PDQ during postexposure baking (PEB) after preneutralization at RT 30,31) were calculated by solving the reaction-diffusion equations 32) and using the Monte Carlo method. 33) The calculation methods have been described in detail elsewhere.…”