Direct Fabrication of All-Inorganic Logic Elements and Microelectromechanical Systems from Nanoparticle Precursors
- PDF / 1,075,388 Bytes
- 7 Pages / 612 x 792 pts (letter) Page_size
- 90 Downloads / 176 Views
DIRECT FABRICATION OF ALL-INORGANIC LOGIC ELEMENTS AND MICROELECTROMECHANICAL SYSTEMS FROM NANOPARTICLE PRECURSORS
Colin Bulthaup, Eric Wilhelm, Brian Hubert, Brent Ridley, and Joe Jacobson Media Lab, Massachusetts Institute of Technology, Cambridge, MA 02139
ABSTRACT Here we describe the fabrication of electrostatic motors by liquid embossing, a contact stamp-based method of patterning liquids with sub-micron resolution. We also demonstrate AFM nano-assembly which can produce sub-40 nm dots and lines by transferring either liquid or solid material from a reservoir to a deposition area. Both of these non-lithographic patterning techniques are applicable to nanocrystal, organic, and polymeric solutions and liquids.
LIQUD EMBOSSING Liquid embossing is a physical process used to directly pattern features in functional materials [1-3]. We have demonstrated that the process can be used to pattern a wide range of materials including solutions of nanocrystals, spin-on glasses, insulating polymers, and aqueous biological solutions. Resolutions down to 200nm over areas exceeding 100cm2 have been reliably patterned with high yield. Prior work on non-lithographic patterning has been primarily based on microcontact printing [4-14] or nanoimprinting [15-17] a resist which acts as an etch mask for subsequent conventional liquid- or dry-etch techniques. Research groups have investigated other patterning techniques including microcontact printing a colloidal electroplating catalyst [18], molding or imprinting organic light emitters [19, 20], and micromolding organic or sol-gel materials [2126]. No additive printing technique has been reported with the ability to rapidly and directly pattern arbitrary sub-micron structures. Liquid embossing overcomes these limitations of the prior art through two critical differences. The first is that the patterned material remains a liquid throughout the embossing process, whereas prior techniques required that the material undergo a phase change during the patterning. Because of this, liquid embossing uniquely enables the rapid processing of a diverse materials set that ranges from aqueous biomolecules to polymers and inorganic nanocrystals in heavy organic solvents. The second difference is that the emboss pushes completely through the thin liquid film contacting the substrate beneath. This enables the additive fabrication of electrically isolated features and the direct formation of vias, both without the etching required for contact-printing [4-14] and imprint [15-17] schemes. The first step in the liquid embossing process is the creation of an elastomeric stamp. The stamp is created by casting PDMS on top of a master which is typically made of photoresist on a silicon wafer, but can in principle be any surface with raised physical features. As shown in Fig. 2, the stamp is then brought into contact with a thin film of functional material in liquid phase. The raised features on the stamp push through the thin liquid film to the underlying substrate. D10.4.1
The stamp is then removed while
Data Loading...
