Study of the Reaction of Acid Generators with Epithermal and Thermalized Electrons

Self Cite

333

319

Historically, in the mass production of semiconductor devices, exposure tools have been repeatedly replaced with those with a shorter wavelength to meet the resolution requirements projected in the International Technology Roadmap for Semiconductors issued by the Semiconductor Industry Association. After ArF immersion lithography, extreme ultraviolet (EUV; 92.5 eV) radiation is expected to be used as an exposure tool for the mass production at or below the 22 nm technology node. If realized, 92.5 eV EUV will be the first ionizing radiation used for the mass production of semiconductor devices. In EUV lithography, chemically amplified resists, which have been the standard resists for mass production since the use of KrF lithography, will be used to meet the sensitivity requirement. Above the ionization energy of resist materials, the fundamental science of imaging, however, changes from photochemistry to radiation chemistry. In this paper, we review the radiation chemistry of materials related to chemically amplified resists. The imaging mechanisms from energy deposition to proton migration in resist materials are discussed.

Section: )mentioning

confidence: 99%

Radiation Chemistry in Chemically Amplified Resists

Kozawa

Tagawa

2010

Self Cite

333

319

“…23) The photodecomposable quencher used was assumed to decompose through dissociative electron attachment, similarly to the decomposition of TPS-Tf. 24,25) This is an assumption based on the analogy of their molecular structures. However, it is later shown that the image quality cannot be improved unless an efficient decomposition mechanism comparable to that of acid generators is assumed.…”

Section: Simulation Model and Methodsmentioning

confidence: 99%

Effect of photodecomposable quencher on latent image quality in extreme ultraviolet lithography

Kozawa

2014

Self Cite

A basic compound, called a quencher, plays an important role in the formation of latent images in chemically amplified resists. In this study, the effect of photodecomposable quenchers on latent image quality was investigated using a simulation on the basis of the reaction mechanisms of chemically amplified extreme ultraviolet (EUV) resists. When the concentration of photodecomposable quenchers was relatively low (>10% of the acid generator concentration), the effect of photodecomposable quenchers was negligible because of the competition between acid generators and photodecomposable quenchers for thermalized electrons. When the concentration of photodecomposable quenchers was increased, latent image quality was improved, compared with that in the resist with non-photodecomposable quenchers. The concentration of photodecomposable quenchers relative to that of acid generators has to be increased to some degree for photodecomposable quenchers to enhance latent image quality.

“…25) The photodecomposable quencher used was assumed to decompose through dissociative electron attachment, similarly to the decomposition of TPS-Tf. 26,27) Although this is an assumption based on the analogy of their molecular structures, it has been reported that the image quality cannot be improved unless an efficient decomposition mechanism comparable to that of acid generators is assumed. 17) The reaction radius of the photodecomposable quenchers with thermalized electrons was assumed to be the same as that of TPS-Tf.…”

Section: Simulation Model and Methodsmentioning

confidence: 99%

Effects of dose shift on line width, line edge roughness, and stochastic defect generation in chemically amplified extreme ultraviolet resist with photodecomposable quencher

Kozawa¹

2014

Self Cite

In chemically amplified resists used for high-volume production of semiconductor devices, the control of acid catalytic reaction is essential for fine patterning. A basic compound, called a quencher, plays an important role in the control of acid catalytic reaction. In particular, the photodecomposable quencher is effective for the enhancement of the chemical gradient. In this study, the effects of photodecomposable quenchers on the dose shift (the deviation from the sizing dose) dependences of line width, line edge roughness (LER), and stochastic defect generation were investigated, assuming line-and-space patterns with 11 nm half-pitch. The exposure latitude of line width in a chemically amplified resist with photodecomposable quenchers was larger than that in a chemically amplified resist with conventional non-photodecomposable quenchers at sizing doses >20 mJ cm %2 . By using photodecomposable quenchers, LER and the probability of stochastic defect generation were decreased, while the dose shift dependences of LER and stochastic defect generation did not significantly differ, compared with those observed using conventional non-photodecomposable quenchers.