Nano-Scale MOSFET Devices Fabricated Using a Novel Carbon-Nanotube-based Lithography
- PDF / 1,892,487 Bytes
- 6 Pages / 595 x 842 pts (A4) Page_size
- 41 Downloads / 223 Views
0913-D04-07
Nano-Scale MOSFET Devices Fabricated Using a Novel Carbon-Nanotube-Based Lithography Jaber Derakhshandeh1, Yaser Abdi1,2, Shams Mohajerzadeh1, Mohammad Beikahmadi1, Ashkan Behnam1, Ezatollah Arzi2, Michael D. Robertson3, and C. J. Bennett3 1 Electrical & Computer Eng., Thin Film Laboratory, Department of Electrical and Computer Eng, University of Tehran, Tehran, Iran, Tehran, Tehran, 14395/515, Iran 2 Department of Physics, University of Tehran, Tehran, Iran, Tehran, Tehran, 14395/515, Iran 3 Department of Physics, Acadia University, Wolfville, Nova Scotia, B4P 2R6, Canada ABSTRACT: PECVD-grown carbon nanotubes on (100) silicon substrates have been studied and exploited for electron emission applications. The growth of CNT's is achieved by a mixture of hydrogen and acetylene gases in a CVD reactor and a 2-5nm thick nickel is used as the seed for the growth. The presence of DC-plasma yields a vertical growth and allows deposition at temperatures below 650oC. The grown nano-tubes are encapsulated by means of an insulating TiO2 layer, leading to beam-shape emission of electrons from the cathode towards the opposite anode electrode. The electron emission occurs using an anode-cathode voltage of 100 V with ability of direct writing on a photo-resist coated substrates. Straight lines with widths between 50 and 200nm have been successfully drawn. Scanning electron and transmission electron microscopy have been used to investigate the quality and fineness of the results. This technique has been applied on P-type (100) silicon substrates for the formation of the gate region of N-MOSFET devices, showing a drive current of 310µA/µm and Cox of 0.7µF/cm2. INTRODUCTION Modern MOSFET devices lend their success to the fine patterning of their gate constituent. The formation of ultra-fine gate regions requires high resolution lithography techniques beyond the capability of standard photo-lithography. There are several techniques for submicron and nano-lithography among which one can refer to the electron beam writing, ion beam lithography and extreme deep ultra violet lithography [1-3]. Electron beam writing is essentially capable of generating patterns in nano-meter scale, especially down to 10 nm regime. This technique can be used for writing the gate pattern and it is a time consuming method. By scanning the electron beam over an electro-resist coated sample desired patterns are generated on the sample. Usually electron energies in the range of 10-20 keV are exploited. High density polymers as PMMA are being used to minimize the proximity effect, a side-effect of the leaching of energetic electrons. On the other hand carbon nanotubes are suitable choices for emission of electrons, provided a proper electron beam is formed. The vertical growth of carbon nanotubes on silicon substrates is the most crucial step in achieving suitable electron emission. Several techniques are being exploited for the growth of single-wall and multi-wall nanotubes among which one can highlight the thermal catalyst-based CVD, laser vaporizat
Data Loading...
