Impact of 2-Methyl-2-Adamantyl Group Used for 193-nm Single-Layer Resist

JapanDeblocking reaction mechanisms and lithographic performance in chemically amplified positive ArF resists were investigated by analyzing acid concentration and blocking levels. The resists consisted of poly(carboxytetracyclododecyl methacrylateS0-co-ethoxyethylcarboxytetracyclododecyl methacrylate50), poly(carboxytetracyclododecyl methacrylate70-co-tetrahydropyranylcarboxytetracyclododecyl methacrylate30), or poly(tricyclodecylacrylate~0-co-tetrahydropyranylmethacrylate20-co-methacrylic acid20), and triphenylsulfonium triflate as a photo acid generator. The deblocking reaction mechanisms were evaluated from Arrhenius plots of the deblocking reaction rate constant. It was found that the deblocking reaction of all resists is ruled by two rate-determining steps -a reactioncontrolled step in the low-temperature region and an acid-diffusion-controlled step in the high-temperature region. Furthermore, the relationship between deblocking reaction and lithographic performance, especially post exposure delay (PED) stability was investigated. As a result, it has been concluded that small acid loss induces better PED stability.

Section: Introductionmentioning

confidence: 99%

Deblocking reaction of chemically amplified positive DUV resists.

Yamana

Itani

Yoshino

et al. 1999

“…The resist formulations were based on a Fujitsulike [16] resist containing a copolymer of a lactone methacrylate and methyl-2-adamantyl methacrylate.…”

Section: Experimental 21 Formulationmentioning

confidence: 99%

Transparency versus Efficiency: Important Considerations in the Design of Photoacid Generators for ArF Lithography.

Cameron¹,

Pohlers²,

Suzuki³

et al. 2002

The advent of 193nm lithography has stimulated the search for novel photocid generators (PAGs) with increased transparency at 193nm. This need for more transparency stems from the use of phenyl groups in the classic 248nm PACs, such as triphenylsulfonium salts. Unfortunately for 193nm resist development, the phenyl group is highly absorbing at that wavelength, thereby severely restricting the PAG formulation space. It has not yet been pointed out, however, that photoacid generation efficiency has also become more important for 193nm systems. The reason is that 193 polymers cannot sensitize the PAG, as is the case for 248nm phenolic systems, i.e. the light absorbed by the polymer does not contribute to acid generation. Furthermore, the photoacid generation efficiency of sulfonium PACs drops considerably when going from 248nm to 193nm. Thus, the ability to quantify the photoefficiency of a new PAG quickly becomes key to successful new 193nm PAG development. While there are many ways to determine the quantum yield of photoacid generation (I of PACs, they are usually both time and labor-intensive. Therefore, in the first part of this paper, we describe the Pparameter as a fast, simple and more practical way than the quantum yield, 1 to characterize the photoefficiency of a PAG. Results for a number of sulfonium PAGs at both 248 and 193nm are determined this way, and the observed trends are discussed. In the second part of this work we investigate how lithographic performance is impacted by those two parameters. A transparency/efficiency matrix of nine PAGs is evaluated in a standard 193nm resist formulation. The results indicate that the PAGs with a combination of high efficiency and high transparency yield the best lithographic results, underlining the importance of efficiency and transparency as key parametesr in 193nm PAG design.

“…Methacrylate polymer based resists [1][2][3][4][5] generally offer the best performance for contact hole applications in terms of resolution and DoF due to their high dissolution contrast. Some advanced resists are capable of resolving 100 nm CDs with the use of optical enhancement techniques.…”

Section: Introductionmentioning

confidence: 99%

Optimization of 193 nm Contact Hole Resists for 100 nm Node.

Kudo

Alemy

Dammel

et al. 2002

San 136-1, Ami-ri, Bubal-eub, Ichon-si, Korea This paper discusses the 193 nm lithography of contact holes with various pitches for 100 nm node. We have studied 193 nm contact hole resists in view of resist components, process conditions and optical settings. Sidewall roughness was improved by optimizing photoacid generators. Side lobes were eliminated by applying higher post exposure bake temperature or modification of polymers. The influence of optical settings, types of masks and mask bias was discussed with simulation and lithographic results and guidelines for better resolution and iso-dense bias were proposed. The optimized formulation, AZ® AXTM l O50P has a high resolution combined with a large depth of focus and an iso-dense overlap window (130 nm (NA=0.63) DOF 0.38 µm C Exposure latitude 10%).