bottom up process for nenometirial
- 1. SARDAR VALLBHBHAI PATEL INSTITUTE OF TECHNOLOGY NAME:- Sangani Ankur G. BRANCH:- Information & Technology ID NO:- 16beitv122 BATCH:- B SUB:- Physics TOPIC:- Bottom up Processing Nanomaterials
- 2. Bottom-Up Approach The opposite of the top-down approach. Instead of taking material away to make structures, the bottom-up approach selectively adds atoms to create structures.
- 3. The Ideas Behind the Bottom-up Approach Nature uses the bottom up approach. − Cells − Crystals − Humans Chemistry and biology can help to assemble and control growth.
- 4. Top-Down v Bottom-up Etched wafer with desired pattern Apply layer of photoresist Expose wafer with UV light through mask and etch wafer Start with bulk wafer Top Down Process Bottom Up Process Start with bulk wafer Alter area of wafer where structure is to be created by adding polymer or seed crystals or other techniques. Grow or assemble the structure on the area determined by the seed crystals or polymer. (self assembly) Similar results can be obtained through bottom-up and top-down processes
- 5. Why is Bottom-Up Processing Needed? Allows smaller geometries than photolithography. Certain structures such as Carbon Nanotubes and Si nanowires are grown through a bottom-up process. New technologies such as organic semiconductors employ bottom-up processes to pattern them. Can make formation of films and structures much easier. Is more economical than top-down in that it does not waste material to etching.
- 6. Self Assembly The principle behind bottom-up processing. Self assembly is the coordinated action of independent entities to produce larger, ordered structures or achieve a desired shape. Found in nature. Start on the atomic scale.
- 7. Applications of Bottom-Up Processing Self-organizing deposition of silicon nanodots. Formation of Nanowires. Nanotube transistor. Self-assembled monolayers. Carbon nanotube interconnects.
- 8. Challenges for the Bottom-Up Approach Making sure that the structures grow and assemble in the correct way. Forming complex patterns and structures using self assembly. Contamination has a significant impact on devices with such small geometries. Fabricating robust structures.
- 9. Strategies for Bottom-Up Processing Combination of top- down and bottom- up processes to simplify construction. Use catalysts and stresses to achieve more one- directional growth.
- 10. What to Look For Vias and interconnects being implemented with carbon nanotubes. Nanotube transistors replacing conventional designs. SAMS being used to create organic semiconductor based devices. Carbon nanotubes becoming more and more prevalent as their growth is controlled. Nanotube array possibly used in future televisions.
- 11. Conclusion Top-down processing has been and will be the dominant process in semiconductor manufacturing. Newer technologies such as nanotubes and organic semiconductors will require a bottom-up approach for processing. Self-assembly eliminates the need for photolithography. Bottom-up processing will become more and more prevalent in semiconductor manufacturing.
- 12. Thank You