Patterned nanolithography and functionalized semiconductor surfaces

Patrick T Hurley, Purdue University

Abstract

The manipulation of matter on the nanometer scale has become a central focus from both fundamental and technological perspectives. Unique, unpredictable and highly intriguing physical, optical and electronic phenomena can result from the confinement of matter into nanoscale features. As a result, the burgeoning study and preparation of structures exhibiting such interesting and unusual phenomena has been termed nanotechnology or nanoscience, an exploding field still, however, in its infancy. Much of the driving force for building tiny devices and features on the nanoscale is their importance for existing and emerging technologies such as microelectronics, nanoelectromechanical systems (NEMS), diagnostic and sensors which communicate directly with cells, viruses and bacteria, single electron tunneling, microfluidics, and a host of other applications. Nanofabrication is, however, extremely challenging since perfect control over matter at these dimensions remains difficult. Fundamentally new approaches towards nanoscale manipulation are required to fully exploit the promises and potential of these tiny devices and features. The bulk of this thesis explores an electrochemical cathodic electrografting reaction, which previously has been demonstrated on bulk porous silicon surfaces, can be patterned on the nanoscale utilizing conducting probe atomic force microscopy (CP-AFM) Alkyne electrografting is particularly useful chemical technique since it leads to direct covalent attachment of conjugated alkynes to silicon. In addition, application of a forward bias during the reaction renders the surface less sensitive to oxidation and the resulting monolayers are very stable in air and basic aqueous solution. Alkyne monolayer lines can be drawn down to 40 nm resolution using a Pt-coated AFM tip, and the heights of the monolayers scale the molecular length of the terminal alkynes. The tip is biased (+) and the surface is biased (−) to drive the cathodic electrografting reaction under ambient conditions.

Degree

Ph.D.

Advisors

Buriak, Purdue University.

Subject Area

Chemistry

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