Organic-inorganic hybrid resists are emerging as an effective way of addressing stringent process requirements for aggressive down-scaling of semiconducting devices. However, hybrid resists generally ...require complex chemical synthesis while being predominantly negative-tone with high dose requirements. For positive-tone processes and high-aspect-ratio pattern transfers, resist choices are limited to costly, non-hybrid alternatives, whose etch resistance is still inferior compared with hybrid resists. Here, we demonstrate a novel hybrid positive-tone resist platform utilizing simple
ex situ
vapor-phase inorganic infiltration into standard resist materials. A model system based on poly(methyl methacrylate) (PMMA) thin film hybridized with aluminum oxide has been demonstrated for electron-beam lithography patterning, featuring a fully controllable critical exposure dose, contrast, and etch resistance. The hybrid resist not only achieves contrast as high as ∼30, six-fold enhancement over standard PMMA, but also enables Si nanostructures with resolution down to ∼30 nm and an aspect ratio as high as ∼17, owing to enhancement of the Si etch selectivity to ∼70, with an estimated achievable maximum of ∼300, far exceeding known commercial positive-tone resist systems. The easy implementabilility, combined with versatile
ex situ
control of resist characteristics, makes this hybrid resist synthesis approach uniquely suited for addressing the resist performance and high throughput required for advanced nanolithography techniques, such as extreme ultraviolet lithography, potentially.
Novel positive-tone hybrid resists developed by vapor-phase inorganic infiltration feature fully tunable resist performance parameters and high-aspect-ratio pattern transfer capability.
Abstract
Motivated by the drawbacks of solution phase processing, an all‐dry resist formation process is presented that utilizes amorphous zinc‐imidazolate (aZnMIm) films deposited by ...atomic/molecular layer deposition (ALD/MLD), patterned with electron beam lithography (EBL), and developed by novel low temperature (120 °C) gas phase etching using 1,1,1,5,5,5‐hexafluoroacetylacetone (hfacH) to achieve well‐resolved 22 nm lines with a pitch of 30 nm. The effects of electron beam irradiation on the chemical structure and hfacH etch resistance of aZnMIm films are investigated, and it is found that electron irradiation degrades the 2‐methylimidazolate ligands and transforms aZnMIm into a more dense material that is resistant to etching by hfacH and has a C:N:Zn ratio effectively identical to that of unmodified aZnMIm. These findings showcase the potential for aZnMIm films to function in a dry resist technology. Sensitivity, contrast, and critical dimensions of the patterns are determined to be 37 mC cm
−2
, 0.87, and 29 nm, respectively, for aZnMIm deposited on silicon substrates and patterned at 30 keV. This work introduces a new direction for solvent‐free resist processing, offering the prospect of scalable, high‐resolution patterning techniques for advanced semiconductor fabrication processes.
In Sep 2011, a confident Prime Minister Erdogan visited Libya, Tunisia and Egypt to express Ankara's support for democratic change in the Middle East. After nearly a decade of implementing its ...foreign policy of strategic depth, the Justice and Development Party (AKP) felt that the Arab upheavals had provided Ankara with the opportunity to create a new regional order that placed Turkey at the centre of a region governed by Muslim Brotherhood-affiliated parties. Having previously prioritised relationships with regional autocrats, Sep 2011 thus saw the AKP change tack, embracing its role as a regional inspiration for the states in transition.
The AKP was not prepared for the start of the Arab upheavals in late Dec 2010. Consequently, as events unfolded, Turkey initially reacted cautiously and advocated for cosmetic democratic changes in ...every country affected except Egypt. This article briefly details the AKP's domestic consolidation of power, before discussing Turkey's policies shortly before, during and after the tumult in Tunisia, Egypt and Libya.
This article details Turkey's policies towards Syria, the Israel-Palestine question, and Iraq between 2002 and 2011, as well as the Justice and Development Party's (AKP) relationship with Iran since ...2002. During this period, the AKP's foreign policy towards the Middle East incorporated aspects of the policy of 'strategic depth', while blending this with elements of Turkey's traditional policies of non-interference. This resulted in the formulation of a nuanced and country-specific policy for regional states.
The spread of the Arab upheavals to Syria posed a unique set of problems for Turkey's ruling Justice and Development Party (AKP). Despite Ankara's tepid embrace of political change in Libya, ...then-Prime Minister Recep Tayyip Erdogan tried to capitalise on the changes sweeping through the Arab world. The AKP abandoned its policy of ostpolitik in relation to Egypt, while in Tunisia and Libya the party moved on from its early missteps and was eagerly working with Brotherhood-affiliated political parties.
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