Novolac‐based resists

Abstract

The performance of novolac-diazonaphthoquinone-based positive-working resists is discussed in terms of the molecular weight distributions and microstructures of the novolac resins and the structural variations in the photoactive dissolution inhibitor. Modelling studies leading to recent improvements allowing the delineation of 0.35 pm line and space patterns by ensuring a focal depth of 1.5 pm are outlined. Consideration is also given to the new problems such as pivotal shift and halation that arise in the application of high-resolution photolithography using novolac-diazonaphthoquinone resists.

Novel one-component positive-tone chemically amplified i-line molecular glass photoresist based on tannic acid

“…2-Diazo-1-naphthoquinone-4-sulfonyl chloride(2,1,4-DNQ-Cl) was purified by pouring a solution of 2,1,4-DNQ-Cl in dioxane into excess ethanol. 1 H NMR spectra were measured on a Bruker Avance 500 MHz spectrometer in dimethyl sulfoxide(DMSO-d 6 ). FTIR spectra were obtained with a Nicolet AVATAR 360 spectrometer.…”

“…In the field of the semiconductor industry, diazonaphthoquinone(DNQ)-novolac based positive photoresists systems are widely used for their good thermal stability, high contrast and excellent resistance to dry etching [1][2][3] .…”

“…Phenolic resins are prepared by the condensation reaction of phenols and formaldehyde. The products obtained with this strategy usually associate with some embarrassed problems, such as relative wide molecular weight distribution of phenolic resins, existence of a small amount of monomeric phenols and crosslinked products in the final mixture [4][5][6] . Another key problem is that the reproducibility is poor so that it is difficult to maintain the stable properties of the products.…”

An i-line molecular glass photoresist for high resolution patterning

“…These factors hinder the application of novolac-DNQ based resists for patterning with higher resolution. [3][4][5] Near eld optical lithography (NFOL) is a low-cost high resolution technique which is capable of patterning features beyond the diffraction limit of light. In recent years, some tentative investigation have been made to obtain sub-100 nm resolution patterns using the i-line exposure tool with the concept of near eld lithography.…”

Maskless photolithography: Embossed photoresist as its own optical element

“…Another serious drawback of conventional embossing in the application described here is that the temperature required to soften Novolac-based photoresists results in decomposition of the photosensitive component ͑the diazonaphtho-quinone͒. 6 Exposure to UV light and development of these embossed patterns does not yield features.…”