LabAdviser/Technology Research/Organic Ice Resists for Electron-Beam Lithography - Instrumentation and Processes/Electron-Beam Lithography on Organic Ice Resists: Difference between revisions
| (3 intermediate revisions by the same user not shown) | |||
| Line 2: | Line 2: | ||
=Electron-Beam Lithography on Organic Ice Resists= | =Electron-Beam Lithography on Organic Ice Resists= | ||
[[image:ProcessOIR.png|500px|thumb|Lithography process for Organic Ice Resists]] | |||
Simple organic molecules, e.g. alcohols, condensed to form thin-films at low temperature demonstrate resist-like capabilities for EBL applications and beyond. The entire lithographic process takes place in a single instrument, and avoids exposing users to chemicals and the need of cleanrooms. Unlike EBL that requires large samples with optically flat surfaces, we patterned on fragile membranes only 5 nm-thin, and 2×2 mm2 diamond samples. We created patterns on the nanometer to sub-millimeter scale, as well as three-dimensional structures by stacking layers of frozen organic molecules. Finally, using plasma etching, the organic ice resist (OIR) patterns are used to structure the underlying material, and thus enable nanodevice fabrication. | |||
==Overview== | ==Overview== | ||
| Line 12: | Line 16: | ||
==Organic Ice Resists== | ==Organic Ice Resists== | ||
[[File:Comparison1_OIR.PNG|400px]] | |||
Vapour pressure is the tabulated value at room temperature. Freezing temperature is the tabulated value at atmospheric pressure. | |||
[[File:Comparison2_OIR.PNG|400px]] | |||
Thickness ranges are suggestions based on our experience, and are measured after sublimation via AFM. | |||
==Contrast Curve== | ==Contrast Curve== | ||
[[File:Contrast_OIR.png|600px]] | |||
==Multi-layers== | ==Multi-layers== | ||
| Line 29: | Line 42: | ||
==Diamond Nanofabrication== | ==Diamond Nanofabrication== | ||
[[File:Diamond_OIR.png|400px]] | |||
We defined OIR patterns onto diamond chips as small as 2x2 mm2 to be used as etch mask. OIR layers of well-controlled thickness can be deposited on the entire sample surface, regardless of the shape and sharp corners of the diamond chip, and the one-step lithography reduces manipulating these small samples to a minimum. | |||
To obtain a deeper etch, diamond chips were coated with 10 nm ALD Al2O3 to act as a hard mask, and then a OIR was deposited and patterned. | |||
Due to the insulating nature of diamond, localized charging was occasionally observed, resulting in distortion and displacement of the desired layout in denser exposure areas. A thin Al layer was added on top of the sample to ground it through the SEM clip, which solved the issue without affecting the following etch steps. | |||