The document discusses two approaches to fabricating nanostructures: top-down, which involves removing material from larger structures to make smaller ones, and bottom-up, which involves adding material to small structures to create larger ones. It then focuses on top-down techniques like e-beam lithography, scanning tunneling microscopy (STM), and self-assembly. E-beam lithography can create features as small as 4nm but typically 20-50nm, STM allows atomic manipulation at the nanoscale, and self-assembly uses stresses from lattice mismatches to form quantum dots.

1. Fabrication of Nanostructures

2. Two Fundamental ApproachesTop Down

3. Removing material from a larger structure of make smaller ones.

4. Etching

5. This is the one we will be talking about.

6. Bottom Up

7. Adding material to already small structures to create larger ones.

8. Molecular ChemistryTop down Techniques for Making NanostructuresE-Beam Lithography.

9. Scanning Tunneling Microscopy.

10. Self Assembly.E-beam Lithography Minimum features 4nm.

11. Typical features 20-50nm. As a result of back scattering of electrons.

12. Uses and high energy electron beam to break or add bonds to the photoresist.E-beam Lithography Photo resistsThe high energy electron beam breaks the bonds of positive photoresist.