1. NanoFab Trainer Nick Reeder nick.reeder@sinclair.edu June 28, 2012

2. NanoFab Trainer Educational tool that lets user see the results of performing sequences of basic nano- fabrication operations on a silicon (Si) wafer. Runs under Windows operating system. Written in LabVIEW 2009; requires LabVIEW 2009 Run-Time Engine ( free download at http://joule.ni.com/nidu/cds/view/p/id/1600/lang/en ). http://joule.ni.com/nidu/cds/view/p/id/1600/lang/en

3. User Operations Ion implantation (“doping”) Thermal oxidation Photolithography Depositing layers of material Removing material

4. Ion Implantation Modifies the electrical characteristics of the silicon wafer. Such modification is the key technique underlying the operation of semiconductor devices (diodes, transistors, thyristors). Implanting boron results in “p-type” doping. Implanting phosphorus results in “n-type” doping.

6. Example: Fabricating a MOSFET MOSFET = Metal-oxide-semiconductor field effect transistor

7. Thermal oxidation Grows a layer of silicon dioxide (SiO 2 ) on the wafer surface. Key properties of SiO 2 : – Impervious to ion implantation. – Can be etched away by immersion in hydrofluoric acid (HF), which does not etch silicon.

8. Photolithography Steps in photolithography: – Spin-coat photoresist. – Create and place mask. Mask defines which areas will be exposed to UV light and which areas will be shaded. – Expose with UV light. – “Develop” the photoresist: UV-exposed areas are removed, while shaded areas remain. Wikipedia http://en.wikipedia.org/wiki/Photolithography http://en.wikipedia.org/wiki/Photolithography

9. Depositing Layers Methods of depositing layers of material – Electron-beam evaporation – Chemical vapor deposition (CVD) – Sputtering The materials deposited may be metals, dielectrics, or semiconductors.

10. Removing material Methods of removing material – Wet etching Low-tech Immerse wafer in a bath of liquid acid or solvent – Dry etching High-tech Expose wafer to plasma beam

11. Other Features of Trainer Maintains history of user operations. Will track cost, time, and quality of user operations. “Tutorial” page will provide photos and videos of operations being performed in the lab, along with text explaining theory.