3 nm NiCr wires made using electron beam lithography and PMMA resist

Cumming, David R. S.; Thoms, S.; Weaver, Jonathan; Beaumont, S.P.

doi:10.1016/0167-9317(95)00278-2

Cited by 28 publications

(12 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The authors [26] suggested that these problems might be overcome by using a thinner resist layer, but this will make the transfer process more difficult to realize. Using PMMA in positive tone, Cumming et al [27] fabricated 3 nm wide NiCr wires at approximately 100 nm pitch using 100 keV EBL with a beam current of 12 pA and a 50 nm thick double layer of PMMA resist. The exposure dose was 1.8 nC cm −1 .…”

Section: Organic Resistsmentioning

confidence: 99%

See 1 more Smart Citation

Resists for sub-20-nm electron beam lithography with a focus on HSQ: state of the art

2009

View full text Add to dashboard Cite

In the past decade, the feature size in ultra large-scale integration (ULSI) has been continuously decreasing, leading to nanostructure fabrication. Nowadays, various lithographic techniques ranging from conventional methods (e.g. photolithography, x-rays) to unconventional ones (e.g. nanoimprint lithography, self-assembled monolayers) are used to create small features. Among all these, resist-based electron beam lithography (EBL) seems to be the most suitable technique when nanostructures are desired. The achievement of sub-20-nm structures using EBL is a very sensitive process determined by various factors, starting with the choice of resist material and ending with the development process. After a short introduction to nanolithography, a framework for the nanofabrication process is presented. To obtain finer patterns, improvements of the material properties of the resist are very important. The present review gives an overview of the best resolution obtained with several types of both organic and inorganic resists. For each resist, the advantages and disadvantages are presented. Although very small features (2-5 nm) have been obtained with PMMA and inorganic metal halides, for the former resist the low etch resistance and instability of the pattern, and for the latter the delicate handling of the samples and the difficulties encountered in the spinning session, prevent the wider use of these e-beam resists in nanostructure fabrication. A relatively new e-beam resist, hydrogen silsesquioxane (HSQ), is very suitable when aiming for sub-20-nm resolution. The changes that this resist undergoes before, during and after electron beam exposure are discussed and the influence of various parameters (e.g. pre-baking, exposure dose, writing strategy, development process) on the resolution is presented. In general, high resolution can be obtained using ultrathin resist layers and when the exposure is performed at high acceleration voltages. Usually, one of the properties of the resist material is improved to the detriment of another. It has been demonstrated that aging, baking at low temperature, immediate exposure after spin coating, the use of a weak developer and development at a low temperature increase the sensitivity but decrease the contrast. The surface roughness is more pronounced at low exposure doses (high sensitivity) and high baking temperatures. A delay between exposure and development seems to increase both contrast and the sensitivity of samples which are stored in a vacuum after exposure, compared to those stored in air. Due to its relative novelty, the capabilities of HSQ have not been completely explored, hence there is still room for improvement.Applications of this electron beam resist in lithographic techniques other than EBL are also discussed. Finally, conclusions and an outlook are presented.

show abstract

Section: Organic Resistsmentioning

confidence: 99%

“…However, this process Figure 5. Approximately 3 nm wide NiCr wires using 100 keV EBL and PMMA resist [27]. Reprinted from [27].…”

Section: Organic Resistsmentioning

confidence: 99%

Resists for sub-20-nm electron beam lithography with a focus on HSQ: state of the art

2009

View full text Add to dashboard Cite

show abstract

“…For all critical features on the membrane, ebeam lithography using a double layer PMMA resist followed by liftoff was used [42]. The metal was a stack of 165 nm thick gold with a 15 nm NiCr under layer deposited through evaporation in "A" of step iii.…”

Section: Device Design and Fabricationmentioning

confidence: 99%

Quantification of probe–sample interactions of a scanning thermal microscope using a nanofabricated calibration sample having programmable size

et al. 2016

View full text Add to dashboard Cite

Abstract. We report a method for quantifying scanning thermal microscopy (SThM) probe-sample thermal interactions in-air using a novel temperature calibration device.This new device has been designed, fabricated and characterized using SThM to provide an accurate and spatially variable temperature distribution that can be used as a temperature reference due to its unique design. The device was characterized by means of a microfabricated SThM probe operating in passive mode. This data was interpreted using a heat transfer model, built to describe the thermal interactions during a SThM thermal scan. This permitted the thermal contact resistance between the SThM tip and the device to be determined as 8.33 × 10 5 K/W. It also permitted the probe-sample contact radius to be clarified as being the same size as the probe's tip radius of curvature.Finally, the data was used in the construction of a lumped-system steady state model for the SThM probe and its potential applications were addressed.2

show abstract

“…In many papers, a resolution of developed PMMA patterns bellow 10 nm of isolated features and dense array of 30 nm parallel lines at a pitch of 30 nm (periodic grating) is demonstrated. For this aim thin membrane substrates, thick polymer sub-layer or high accelerating electron energy (80-200 keV), ultrasonic assisted development were used (Moreau et al, 1979;Cumming et al, 1996;Hatzakis, 1998;Yasin et al, 2002) The predominant mechanism of polymer solubility modification in PMMA is chain scission between the carbon atoms changing the molecular weight distribution and decomposition of carbonyl radicals to volatile products. The required irradiation dose is high (as example 50 µC/cm 2 at 20 keV accelerating electron energy and developer methyl butyl ketone -MIBK).…”

Section: Pmma In Nanolithographymentioning

confidence: 99%

Computer Simulation of Processes at Electron and Ion Beam Lithography, Part 2: Simulation of Resist Developed Images at Electron and Ion Beam Lithography

Vutova¹,

Koleva²,

Mladenov³

2010

Lithography

View full text Add to dashboard Cite

3 nm NiCr wires made using electron beam lithography and PMMA resist

Cited by 28 publications

References 7 publications

Resists for sub-20-nm electron beam lithography with a focus on HSQ: state of the art

Resists for sub-20-nm electron beam lithography with a focus on HSQ: state of the art

Quantification of probe–sample interactions of a scanning thermal microscope using a nanofabricated calibration sample having programmable size

Computer Simulation of Processes at Electron and Ion Beam Lithography, Part 2: Simulation of Resist Developed Images at Electron and Ion Beam Lithography

Contact Info

Product

Resources

About